Zoonoses

WASHINGTON — Advancing treatment for what has been variably called chronic Lyme and posttreatment Lyme disease (PTLD) is under the eyes of a National Academies of Science, Engineering, and Medicine (NASEM) committee of experts for the first time — a year after the NASEM shone a spotlight on the need to accelerate research on chronic illnesses that follow known or suspected infections.

The committee will not make recommendations on specific approaches to diagnosis and treatment when it issues a report in early 2025 but will instead present “consensus findings” on treatment for chronic illness associated with Lyme disease, including recommendations for advancing treatment.

There have been only a few randomized controlled trials (RCTs) conducted on what the committee is calling Lyme Infection-Associated Chronic Illness (Lyme IACI) for now, and no National Institutes of Health (NIH)-funded RCTs in the past 20 years or so. It’s an area void of the US Food and Drug Administration–approved therapies, void of any consensus on the off-label use of medications, and without any current standard of care or proven mechanisms and pathophysiology, said John Aucott, MD, director of the Johns Hopkins Medicine Lyme Disease Clinical Research Center, Baltimore, one of the invited speakers at a public meeting held by the NASEM in Washington, DC.

“The best way to look at this illness is not from the silos of infectious disease or the silos of rheumatology; you have to look across disciplines,” Dr. Aucott, also associate professor of medicine in the Division of Rheumatology, told the committee. “The story doesn’t fit anything I trained for in my infectious disease fellowship. Even today, I’d posit that PTLD is like an island — it’s still not connected to a lot of the mainstream of medicine.”

Rhisa Parera, who wrote and directed a 2021 documentary, Your Labs Are Normal, was one of several invited speakers who amplified the patient voice. Starting around age 7, she had pain in her knees, spine, and hips and vivid nightmares. In high school, she developed gastrointestinal issues, and in college, she developed debilitating neurologic symptoms.

Depression was her eventual diagnosis after having seen “every specialist in the book,” she said. At age 29, she received a positive western blot test and a Lyme disease diagnosis, at which point “I was prescribed 4 weeks of doxycycline and left in the dark,” the 34-year-old Black patient told the committee. Her health improved only after she began working with an “LLMD,” or Lyme-literate medical doctor (a term used in the patient community), while she lived with her mother and did not work, she said.

“I don’t share my Lyme disease history with other doctors. It’s pointless when you have those who will laugh at you, say you’re fine if you were treated, or just deny the disease completely,” Ms. Parera said. “We need this to be taught in medical school. It’s a literal emergency.”
 

Incidence and Potential Mechanisms

Limited research has suggested that 10%-20% of patients with Lyme disease develop persistent symptoms after standard antibiotic treatment advised by the Infectious Diseases Society of America (IDSA), Dr. Aucott said. (On its web page on chronic symptoms, the Centers for Disease Control and Prevention presents a more conservative range of 5%-10%.)

His own prospective cohort study at Johns Hopkins, published in 2022, found that 13.7% of 234 patients with prior Lyme disease met symptom and functional impact criteria for PTLD, compared with 4.1% of 49 participants without a history of Lyme disease — a statistically significant difference that he said should “put to rest” the question of “is it real?”

PTLD is the research case definition proposed by the IDSA in 2006; it requires that patients have prior documented Lyme disease, no other specific comorbidities, and specific symptoms (fatigue, widespread musculoskeletal pain, and/or cognitive difficulties) causing significant functional impact at least 6 months from their initial diagnosis and treatment.

In the real world, however, where diagnostics for acute Lyme disease are often inaccurate, erythema migrans is often absent, and the symptomatology of Lyme IACI is variable (and where there is no approved laboratory test or objective biomarker for diagnosing Lyme IACI), PTLD represents only a subset of a broader, heterogeneous population with persistent symptoms.

The term “Lyme IACI,” pronounced “Lyme eye-ACK-ee” at the meeting, builds on conversations at the 2023 NASEM workshop on infection-associated chronic illnesses and “encompasses a variety of terms that are used,” including PTLD, PTLD syndrome, persistent Lyme disease, and chronic Lyme disease, according to committee documents. Symptoms are distinct from the known complications of Lyme disease, such as arthritis or carditis.

The findings from Dr. Aucott’s SLICE cohort likely represent “the best outcome,” he said. They’re “probably not generalizable to a community setting where we see lots of missed diagnoses and delayed diagnoses,” as well as other tick-borne coinfections.

One of the challenges in designing future trials, in fact, relates to enrollment criteria and whether to use strict inclusion and exclusion criteria associated with the IDSA definition or take a broader approach to trial enrollment, he and others said. “You want to enroll patients for whom there’s no controversy that they’ve had Lyme infection ... for a study people believe in,” Dr. Aucott said during a discussion period, noting that it’s typical to screen over 100 patients to find one enrollee. “But it’s a tension we’re having.”

Timothy Sellati, PhD, chief scientific officer of the Global Lyme Alliance, urged change. “It’s really important to try to figure out how to alter our thinking on identifying and diagnosing chronic Lyme patients because they need to be recruited into clinical trials,” he said during his presentation.

“We think the best way to do this is to [develop and] employ composite diagnostic testing” that looks at unique Borrelia signatures (eg, protein, DNA, RNA, or metabolites), genetic and/or epigenetic signatures, inflammation signatures, T-cell-independent antibody signatures, and other elements, Dr. Sellati said.

Researchers designing treatment trials also face unknowns, Dr. Aucott and others said, about the role of potential mechanisms of Lyme IACI, from persistent Borrelia burgdorferi (or Borrelia mayonii) infection or the persistence of bacterial remnants (eg, nucleic acids or peptidoglycans) to infection-triggered pathology such as persistent immune dysregulation, chronic inflammation, autoimmunity, microbiome alterations, and dysautonomia and other neural network alterations.

The NASEM’s spotlight on Lyme IACI follows its long COVID-driven push last year to advance a common research agenda in infection-associated chronic illnesses. Investigators see common symptoms and potential shared mechanisms between long COVID, Lyme IACI, myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), and other complex chronic illnesses following infections.

At the Lyme IACI meeting, invited speakers described parts of the research landscape. Avindra Nath, MD, of the National Institute of Neurological Disorders and Stroke, for instance, described a recently published deep phenotyping study of 17 patients with ME/CFS that found decreased central catecholamine synthesis, circuit dysfunction of integrative brain regions, and immune profiling differences (eg, defects in B-cell maturation or T-cell exhaustion), compared with matched controls, that suggest the persistence of microbial antigens.

And John Leong, MD, PhD, of Tufts University, Boston, described his lab’s focus on understanding the microbe-host interactions that enable bloodstream dissemination and tissue invasion of B burgdorferi to take hold, increasing the risk for persistent symptoms. Other research at Tufts, he noted during a discussion period, has demonstrated the persistence of B burgdorferi to antibiotics in microtiter dishes. “Those organisms that survive are really difficult to eradicate in vitro,” Dr. Leong said.

Other physician investigators described research on nociplastic pain — a category of pain that can be triggered by infections, causing both amplified sensory processing and augmented central nervous system pain — and on whether reactivation of the Epstein-Barr virus could potentiate autoimmunity in the context of Borrelia infection.

Researchers are ready to test therapies while pathophysiology is unraveled — provided there is funding, Dr. Aucott said. The Clinical Trials Network for Lyme and Other Tick-Borne Diseases, coordinated by Brian Fallon, MD, of Columbia University, New York City, and funded several years ago by the Steven & Alexandra Cohen Foundation, has a slate of small pilot studies underway or being planned that address potential mechanisms (eg, studies of pulse intravenous ceftriaxone, tetracycline, transauricular vagus nerve stimulation, and mast cell modulation). And should full multisite trials be designed and funded, the network is ready with an infrastructure.
 

Need for Patient-Centered Outcomes

Persistent symptomatology is on the NIH’s radar screen. Efforts to understand causes were part of a strategic tick-borne disease research plan developed by the NIH in 2019. And in 2023, the National Institute of Allergy and Infectious Diseases (NIAID) funded seven projects addressing persistent symptoms that will run through 2028, C. Benjamin Beard, PhD, deputy division director of the CDC’s Division of Vector-Borne Disease, said at the NASEM committee meeting.

Patient advocates maintained that too much emphasis is placed on tick biology and pathophysiology. When Wendy Adams, research grant director and advisory board member of the Bay Area Lyme Foundation, and a colleague analyzed NIAID tick-borne disease funding from 2013 to 2021, they found that 75% of the funding went toward basic research, 15% to translational research, and “only 3% went to clinical research,” Ms. Adams told the committee.

Only 3% of the basic research budget was spent on coinfections, she said, and only 1% was spent on neurologic disease associated with tick-borne infections, both of which are survey-defined patient priorities. Moreover, “12% of the overall NIAID [tick-borne diseases] budget was spent on tick biology,” she said.

Research needs to involve community physicians who are utilizing the guidelines and approaches of the International Lyme and Associated Diseases Society to treat most patients with Lyme IACI, Ms. Adams said. “They have data to be mined,” she said, as does LymeDisease.org, which maintains a patient registry, MyLymeData, with over 18,000 patients. The organization has published two treatment studies, including one on antibiotic treatment response.

Lorraine Johnson, JD, MBA, CEO of LymeDisease.org and principal investigator of MyLymeData, stressed the importance of using patient-centered outcomes that incorporate minimal clinically important differences (MCIDs). “A change in the SF-36 score [without consideration of MCIDs] is not inherently important or meaningful to patients,” she said, referring to the SF-36 survey of health-related quality of life.

“This may seem like an esoteric issue, but two of the four clinical trials done [on retreatment of] persistent Lyme disease used the SF-36 as their outcome measure, and those studies, led by [Mark] Klempner, concluded that retreatment was not effective,” Ms. Johnson said. “Patients have been and continue to be harmed by [this research] because they’re told by physicians that antibiotics don’t work.”

A 2012 biostatistical review of these four RCTs — trials that helped inform the 2006 IDSA treatment guidelines — concluded that the Klempner studies “set the bar for treatment success too high,” Ms. Johnson said. Three of the four trials were likely underpowered to detect clinically meaningful treatment effects, the review also found.

The NASEM committee will hold additional public meetings and review a wide range of literature through this year. The formation of the committee was recommended by the US Department of Health and Human Services Tick-Borne Disease Working Group that was established by Congress in 2016 and concluded its work in 2022. The committee’s work is funded by the Cohen Foundation.
 

A version of this article appeared on Medscape.com.

WASHINGTON — Advancing treatment for what has been variably called chronic Lyme and posttreatment Lyme disease (PTLD) is under the eyes of a National Academies of Science, Engineering, and Medicine (NASEM) committee of experts for the first time — a year after the NASEM shone a spotlight on the need to accelerate research on chronic illnesses that follow known or suspected infections.

The committee will not make recommendations on specific approaches to diagnosis and treatment when it issues a report in early 2025 but will instead present “consensus findings” on treatment for chronic illness associated with Lyme disease, including recommendations for advancing treatment.

There have been only a few randomized controlled trials (RCTs) conducted on what the committee is calling Lyme Infection-Associated Chronic Illness (Lyme IACI) for now, and no National Institutes of Health (NIH)-funded RCTs in the past 20 years or so. It’s an area void of the US Food and Drug Administration–approved therapies, void of any consensus on the off-label use of medications, and without any current standard of care or proven mechanisms and pathophysiology, said John Aucott, MD, director of the Johns Hopkins Medicine Lyme Disease Clinical Research Center, Baltimore, one of the invited speakers at a public meeting held by the NASEM in Washington, DC.

“The best way to look at this illness is not from the silos of infectious disease or the silos of rheumatology; you have to look across disciplines,” Dr. Aucott, also associate professor of medicine in the Division of Rheumatology, told the committee. “The story doesn’t fit anything I trained for in my infectious disease fellowship. Even today, I’d posit that PTLD is like an island — it’s still not connected to a lot of the mainstream of medicine.”

Rhisa Parera, who wrote and directed a 2021 documentary, Your Labs Are Normal, was one of several invited speakers who amplified the patient voice. Starting around age 7, she had pain in her knees, spine, and hips and vivid nightmares. In high school, she developed gastrointestinal issues, and in college, she developed debilitating neurologic symptoms.

Depression was her eventual diagnosis after having seen “every specialist in the book,” she said. At age 29, she received a positive western blot test and a Lyme disease diagnosis, at which point “I was prescribed 4 weeks of doxycycline and left in the dark,” the 34-year-old Black patient told the committee. Her health improved only after she began working with an “LLMD,” or Lyme-literate medical doctor (a term used in the patient community), while she lived with her mother and did not work, she said.

“I don’t share my Lyme disease history with other doctors. It’s pointless when you have those who will laugh at you, say you’re fine if you were treated, or just deny the disease completely,” Ms. Parera said. “We need this to be taught in medical school. It’s a literal emergency.”
 

Incidence and Potential Mechanisms

Limited research has suggested that 10%-20% of patients with Lyme disease develop persistent symptoms after standard antibiotic treatment advised by the Infectious Diseases Society of America (IDSA), Dr. Aucott said. (On its web page on chronic symptoms, the Centers for Disease Control and Prevention presents a more conservative range of 5%-10%.)

His own prospective cohort study at Johns Hopkins, published in 2022, found that 13.7% of 234 patients with prior Lyme disease met symptom and functional impact criteria for PTLD, compared with 4.1% of 49 participants without a history of Lyme disease — a statistically significant difference that he said should “put to rest” the question of “is it real?”

PTLD is the research case definition proposed by the IDSA in 2006; it requires that patients have prior documented Lyme disease, no other specific comorbidities, and specific symptoms (fatigue, widespread musculoskeletal pain, and/or cognitive difficulties) causing significant functional impact at least 6 months from their initial diagnosis and treatment.

In the real world, however, where diagnostics for acute Lyme disease are often inaccurate, erythema migrans is often absent, and the symptomatology of Lyme IACI is variable (and where there is no approved laboratory test or objective biomarker for diagnosing Lyme IACI), PTLD represents only a subset of a broader, heterogeneous population with persistent symptoms.

The term “Lyme IACI,” pronounced “Lyme eye-ACK-ee” at the meeting, builds on conversations at the 2023 NASEM workshop on infection-associated chronic illnesses and “encompasses a variety of terms that are used,” including PTLD, PTLD syndrome, persistent Lyme disease, and chronic Lyme disease, according to committee documents. Symptoms are distinct from the known complications of Lyme disease, such as arthritis or carditis.

The findings from Dr. Aucott’s SLICE cohort likely represent “the best outcome,” he said. They’re “probably not generalizable to a community setting where we see lots of missed diagnoses and delayed diagnoses,” as well as other tick-borne coinfections.

One of the challenges in designing future trials, in fact, relates to enrollment criteria and whether to use strict inclusion and exclusion criteria associated with the IDSA definition or take a broader approach to trial enrollment, he and others said. “You want to enroll patients for whom there’s no controversy that they’ve had Lyme infection ... for a study people believe in,” Dr. Aucott said during a discussion period, noting that it’s typical to screen over 100 patients to find one enrollee. “But it’s a tension we’re having.”

Timothy Sellati, PhD, chief scientific officer of the Global Lyme Alliance, urged change. “It’s really important to try to figure out how to alter our thinking on identifying and diagnosing chronic Lyme patients because they need to be recruited into clinical trials,” he said during his presentation.

“We think the best way to do this is to [develop and] employ composite diagnostic testing” that looks at unique Borrelia signatures (eg, protein, DNA, RNA, or metabolites), genetic and/or epigenetic signatures, inflammation signatures, T-cell-independent antibody signatures, and other elements, Dr. Sellati said.

Researchers designing treatment trials also face unknowns, Dr. Aucott and others said, about the role of potential mechanisms of Lyme IACI, from persistent Borrelia burgdorferi (or Borrelia mayonii) infection or the persistence of bacterial remnants (eg, nucleic acids or peptidoglycans) to infection-triggered pathology such as persistent immune dysregulation, chronic inflammation, autoimmunity, microbiome alterations, and dysautonomia and other neural network alterations.

The NASEM’s spotlight on Lyme IACI follows its long COVID-driven push last year to advance a common research agenda in infection-associated chronic illnesses. Investigators see common symptoms and potential shared mechanisms between long COVID, Lyme IACI, myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), and other complex chronic illnesses following infections.

At the Lyme IACI meeting, invited speakers described parts of the research landscape. Avindra Nath, MD, of the National Institute of Neurological Disorders and Stroke, for instance, described a recently published deep phenotyping study of 17 patients with ME/CFS that found decreased central catecholamine synthesis, circuit dysfunction of integrative brain regions, and immune profiling differences (eg, defects in B-cell maturation or T-cell exhaustion), compared with matched controls, that suggest the persistence of microbial antigens.

And John Leong, MD, PhD, of Tufts University, Boston, described his lab’s focus on understanding the microbe-host interactions that enable bloodstream dissemination and tissue invasion of B burgdorferi to take hold, increasing the risk for persistent symptoms. Other research at Tufts, he noted during a discussion period, has demonstrated the persistence of B burgdorferi to antibiotics in microtiter dishes. “Those organisms that survive are really difficult to eradicate in vitro,” Dr. Leong said.

Other physician investigators described research on nociplastic pain — a category of pain that can be triggered by infections, causing both amplified sensory processing and augmented central nervous system pain — and on whether reactivation of the Epstein-Barr virus could potentiate autoimmunity in the context of Borrelia infection.

Researchers are ready to test therapies while pathophysiology is unraveled — provided there is funding, Dr. Aucott said. The Clinical Trials Network for Lyme and Other Tick-Borne Diseases, coordinated by Brian Fallon, MD, of Columbia University, New York City, and funded several years ago by the Steven & Alexandra Cohen Foundation, has a slate of small pilot studies underway or being planned that address potential mechanisms (eg, studies of pulse intravenous ceftriaxone, tetracycline, transauricular vagus nerve stimulation, and mast cell modulation). And should full multisite trials be designed and funded, the network is ready with an infrastructure.
 

Need for Patient-Centered Outcomes

Persistent symptomatology is on the NIH’s radar screen. Efforts to understand causes were part of a strategic tick-borne disease research plan developed by the NIH in 2019. And in 2023, the National Institute of Allergy and Infectious Diseases (NIAID) funded seven projects addressing persistent symptoms that will run through 2028, C. Benjamin Beard, PhD, deputy division director of the CDC’s Division of Vector-Borne Disease, said at the NASEM committee meeting.

Patient advocates maintained that too much emphasis is placed on tick biology and pathophysiology. When Wendy Adams, research grant director and advisory board member of the Bay Area Lyme Foundation, and a colleague analyzed NIAID tick-borne disease funding from 2013 to 2021, they found that 75% of the funding went toward basic research, 15% to translational research, and “only 3% went to clinical research,” Ms. Adams told the committee.

Only 3% of the basic research budget was spent on coinfections, she said, and only 1% was spent on neurologic disease associated with tick-borne infections, both of which are survey-defined patient priorities. Moreover, “12% of the overall NIAID [tick-borne diseases] budget was spent on tick biology,” she said.

Research needs to involve community physicians who are utilizing the guidelines and approaches of the International Lyme and Associated Diseases Society to treat most patients with Lyme IACI, Ms. Adams said. “They have data to be mined,” she said, as does LymeDisease.org, which maintains a patient registry, MyLymeData, with over 18,000 patients. The organization has published two treatment studies, including one on antibiotic treatment response.

Lorraine Johnson, JD, MBA, CEO of LymeDisease.org and principal investigator of MyLymeData, stressed the importance of using patient-centered outcomes that incorporate minimal clinically important differences (MCIDs). “A change in the SF-36 score [without consideration of MCIDs] is not inherently important or meaningful to patients,” she said, referring to the SF-36 survey of health-related quality of life.

“This may seem like an esoteric issue, but two of the four clinical trials done [on retreatment of] persistent Lyme disease used the SF-36 as their outcome measure, and those studies, led by [Mark] Klempner, concluded that retreatment was not effective,” Ms. Johnson said. “Patients have been and continue to be harmed by [this research] because they’re told by physicians that antibiotics don’t work.”

A 2012 biostatistical review of these four RCTs — trials that helped inform the 2006 IDSA treatment guidelines — concluded that the Klempner studies “set the bar for treatment success too high,” Ms. Johnson said. Three of the four trials were likely underpowered to detect clinically meaningful treatment effects, the review also found.

The NASEM committee will hold additional public meetings and review a wide range of literature through this year. The formation of the committee was recommended by the US Department of Health and Human Services Tick-Borne Disease Working Group that was established by Congress in 2016 and concluded its work in 2022. The committee’s work is funded by the Cohen Foundation.
 

A version of this article appeared on Medscape.com.

WASHINGTON — Advancing treatment for what has been variably called chronic Lyme and posttreatment Lyme disease (PTLD) is under the eyes of a National Academies of Science, Engineering, and Medicine (NASEM) committee of experts for the first time — a year after the NASEM shone a spotlight on the need to accelerate research on chronic illnesses that follow known or suspected infections.

The committee will not make recommendations on specific approaches to diagnosis and treatment when it issues a report in early 2025 but will instead present “consensus findings” on treatment for chronic illness associated with Lyme disease, including recommendations for advancing treatment.

There have been only a few randomized controlled trials (RCTs) conducted on what the committee is calling Lyme Infection-Associated Chronic Illness (Lyme IACI) for now, and no National Institutes of Health (NIH)-funded RCTs in the past 20 years or so. It’s an area void of the US Food and Drug Administration–approved therapies, void of any consensus on the off-label use of medications, and without any current standard of care or proven mechanisms and pathophysiology, said John Aucott, MD, director of the Johns Hopkins Medicine Lyme Disease Clinical Research Center, Baltimore, one of the invited speakers at a public meeting held by the NASEM in Washington, DC.

“The best way to look at this illness is not from the silos of infectious disease or the silos of rheumatology; you have to look across disciplines,” Dr. Aucott, also associate professor of medicine in the Division of Rheumatology, told the committee. “The story doesn’t fit anything I trained for in my infectious disease fellowship. Even today, I’d posit that PTLD is like an island — it’s still not connected to a lot of the mainstream of medicine.”

Rhisa Parera, who wrote and directed a 2021 documentary, Your Labs Are Normal, was one of several invited speakers who amplified the patient voice. Starting around age 7, she had pain in her knees, spine, and hips and vivid nightmares. In high school, she developed gastrointestinal issues, and in college, she developed debilitating neurologic symptoms.

Depression was her eventual diagnosis after having seen “every specialist in the book,” she said. At age 29, she received a positive western blot test and a Lyme disease diagnosis, at which point “I was prescribed 4 weeks of doxycycline and left in the dark,” the 34-year-old Black patient told the committee. Her health improved only after she began working with an “LLMD,” or Lyme-literate medical doctor (a term used in the patient community), while she lived with her mother and did not work, she said.

“I don’t share my Lyme disease history with other doctors. It’s pointless when you have those who will laugh at you, say you’re fine if you were treated, or just deny the disease completely,” Ms. Parera said. “We need this to be taught in medical school. It’s a literal emergency.”
 

Incidence and Potential Mechanisms

Limited research has suggested that 10%-20% of patients with Lyme disease develop persistent symptoms after standard antibiotic treatment advised by the Infectious Diseases Society of America (IDSA), Dr. Aucott said. (On its web page on chronic symptoms, the Centers for Disease Control and Prevention presents a more conservative range of 5%-10%.)

His own prospective cohort study at Johns Hopkins, published in 2022, found that 13.7% of 234 patients with prior Lyme disease met symptom and functional impact criteria for PTLD, compared with 4.1% of 49 participants without a history of Lyme disease — a statistically significant difference that he said should “put to rest” the question of “is it real?”

PTLD is the research case definition proposed by the IDSA in 2006; it requires that patients have prior documented Lyme disease, no other specific comorbidities, and specific symptoms (fatigue, widespread musculoskeletal pain, and/or cognitive difficulties) causing significant functional impact at least 6 months from their initial diagnosis and treatment.

In the real world, however, where diagnostics for acute Lyme disease are often inaccurate, erythema migrans is often absent, and the symptomatology of Lyme IACI is variable (and where there is no approved laboratory test or objective biomarker for diagnosing Lyme IACI), PTLD represents only a subset of a broader, heterogeneous population with persistent symptoms.

The term “Lyme IACI,” pronounced “Lyme eye-ACK-ee” at the meeting, builds on conversations at the 2023 NASEM workshop on infection-associated chronic illnesses and “encompasses a variety of terms that are used,” including PTLD, PTLD syndrome, persistent Lyme disease, and chronic Lyme disease, according to committee documents. Symptoms are distinct from the known complications of Lyme disease, such as arthritis or carditis.

The findings from Dr. Aucott’s SLICE cohort likely represent “the best outcome,” he said. They’re “probably not generalizable to a community setting where we see lots of missed diagnoses and delayed diagnoses,” as well as other tick-borne coinfections.

One of the challenges in designing future trials, in fact, relates to enrollment criteria and whether to use strict inclusion and exclusion criteria associated with the IDSA definition or take a broader approach to trial enrollment, he and others said. “You want to enroll patients for whom there’s no controversy that they’ve had Lyme infection ... for a study people believe in,” Dr. Aucott said during a discussion period, noting that it’s typical to screen over 100 patients to find one enrollee. “But it’s a tension we’re having.”

Timothy Sellati, PhD, chief scientific officer of the Global Lyme Alliance, urged change. “It’s really important to try to figure out how to alter our thinking on identifying and diagnosing chronic Lyme patients because they need to be recruited into clinical trials,” he said during his presentation.

“We think the best way to do this is to [develop and] employ composite diagnostic testing” that looks at unique Borrelia signatures (eg, protein, DNA, RNA, or metabolites), genetic and/or epigenetic signatures, inflammation signatures, T-cell-independent antibody signatures, and other elements, Dr. Sellati said.

Researchers designing treatment trials also face unknowns, Dr. Aucott and others said, about the role of potential mechanisms of Lyme IACI, from persistent Borrelia burgdorferi (or Borrelia mayonii) infection or the persistence of bacterial remnants (eg, nucleic acids or peptidoglycans) to infection-triggered pathology such as persistent immune dysregulation, chronic inflammation, autoimmunity, microbiome alterations, and dysautonomia and other neural network alterations.

The NASEM’s spotlight on Lyme IACI follows its long COVID-driven push last year to advance a common research agenda in infection-associated chronic illnesses. Investigators see common symptoms and potential shared mechanisms between long COVID, Lyme IACI, myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), and other complex chronic illnesses following infections.

At the Lyme IACI meeting, invited speakers described parts of the research landscape. Avindra Nath, MD, of the National Institute of Neurological Disorders and Stroke, for instance, described a recently published deep phenotyping study of 17 patients with ME/CFS that found decreased central catecholamine synthesis, circuit dysfunction of integrative brain regions, and immune profiling differences (eg, defects in B-cell maturation or T-cell exhaustion), compared with matched controls, that suggest the persistence of microbial antigens.

And John Leong, MD, PhD, of Tufts University, Boston, described his lab’s focus on understanding the microbe-host interactions that enable bloodstream dissemination and tissue invasion of B burgdorferi to take hold, increasing the risk for persistent symptoms. Other research at Tufts, he noted during a discussion period, has demonstrated the persistence of B burgdorferi to antibiotics in microtiter dishes. “Those organisms that survive are really difficult to eradicate in vitro,” Dr. Leong said.

Other physician investigators described research on nociplastic pain — a category of pain that can be triggered by infections, causing both amplified sensory processing and augmented central nervous system pain — and on whether reactivation of the Epstein-Barr virus could potentiate autoimmunity in the context of Borrelia infection.

Researchers are ready to test therapies while pathophysiology is unraveled — provided there is funding, Dr. Aucott said. The Clinical Trials Network for Lyme and Other Tick-Borne Diseases, coordinated by Brian Fallon, MD, of Columbia University, New York City, and funded several years ago by the Steven & Alexandra Cohen Foundation, has a slate of small pilot studies underway or being planned that address potential mechanisms (eg, studies of pulse intravenous ceftriaxone, tetracycline, transauricular vagus nerve stimulation, and mast cell modulation). And should full multisite trials be designed and funded, the network is ready with an infrastructure.
 

Need for Patient-Centered Outcomes

Persistent symptomatology is on the NIH’s radar screen. Efforts to understand causes were part of a strategic tick-borne disease research plan developed by the NIH in 2019. And in 2023, the National Institute of Allergy and Infectious Diseases (NIAID) funded seven projects addressing persistent symptoms that will run through 2028, C. Benjamin Beard, PhD, deputy division director of the CDC’s Division of Vector-Borne Disease, said at the NASEM committee meeting.

Patient advocates maintained that too much emphasis is placed on tick biology and pathophysiology. When Wendy Adams, research grant director and advisory board member of the Bay Area Lyme Foundation, and a colleague analyzed NIAID tick-borne disease funding from 2013 to 2021, they found that 75% of the funding went toward basic research, 15% to translational research, and “only 3% went to clinical research,” Ms. Adams told the committee.

Only 3% of the basic research budget was spent on coinfections, she said, and only 1% was spent on neurologic disease associated with tick-borne infections, both of which are survey-defined patient priorities. Moreover, “12% of the overall NIAID [tick-borne diseases] budget was spent on tick biology,” she said.

Research needs to involve community physicians who are utilizing the guidelines and approaches of the International Lyme and Associated Diseases Society to treat most patients with Lyme IACI, Ms. Adams said. “They have data to be mined,” she said, as does LymeDisease.org, which maintains a patient registry, MyLymeData, with over 18,000 patients. The organization has published two treatment studies, including one on antibiotic treatment response.

Lorraine Johnson, JD, MBA, CEO of LymeDisease.org and principal investigator of MyLymeData, stressed the importance of using patient-centered outcomes that incorporate minimal clinically important differences (MCIDs). “A change in the SF-36 score [without consideration of MCIDs] is not inherently important or meaningful to patients,” she said, referring to the SF-36 survey of health-related quality of life.

“This may seem like an esoteric issue, but two of the four clinical trials done [on retreatment of] persistent Lyme disease used the SF-36 as their outcome measure, and those studies, led by [Mark] Klempner, concluded that retreatment was not effective,” Ms. Johnson said. “Patients have been and continue to be harmed by [this research] because they’re told by physicians that antibiotics don’t work.”

A 2012 biostatistical review of these four RCTs — trials that helped inform the 2006 IDSA treatment guidelines — concluded that the Klempner studies “set the bar for treatment success too high,” Ms. Johnson said. Three of the four trials were likely underpowered to detect clinically meaningful treatment effects, the review also found.

The NASEM committee will hold additional public meetings and review a wide range of literature through this year. The formation of the committee was recommended by the US Department of Health and Human Services Tick-Borne Disease Working Group that was established by Congress in 2016 and concluded its work in 2022. The committee’s work is funded by the Cohen Foundation.
 

A version of this article appeared on Medscape.com.

Thanks to decades of successful vector control strategies, vector-borne transmission of Chagas disease has significantly decreased in many regions. Oral ingestion of Trypanosoma cruzi through contaminated food and beverages, however, is increasing. Unlike vector transmission, oral transmission of Chagas disease entails high lethality in pediatric and adult populations.

“The oral transmission of Chagas disease is becoming a much more recognized route, and it is crucial to understand that people can die from this type of transmission,” Norman L. Beatty, MD, assistant professor of infectious diseases and global medicine at the University of Florida College of Medicine in Gainesville, Florida, told this news organization. Dr. Beatty is the lead author of a recent article on the subject.

In regions where the parasite circulates in the environment, people are consuming foods, fruit juices, and possibly wild animal meat that may be contaminated. “As we experience changes in our environment and in the way we consume food, it is crucial to consider how food preparation is carried out in areas where T cruzi transmission occurs in the environment,” said Dr. Beatty. “And as organic farming methods without insecticides become increasingly common, more research is needed in these areas, both in Latin America and in the United States, to understand if oral transmission of T cruzi is occurring.”

In the Amazon basin, foodborne transmission is already the leading cause of acute Chagas disease. It has been described in Argentina, Bolivia, Brazil, Colombia, Ecuador, French Guiana, and Venezuela.

Dr. Beatty’s colleagues recently treated a Brazilian patient at the hospital in Florida. “He came to our hospital very ill, with acute myocarditis after consuming contaminated açaí.” Clarifying that there is widespread awareness about oral transmission in Brazil, he stated, “We are concerned that it may not be recognized in other areas of Latin America.”

Mexico and regions of Central America have little to no information on oral transmission, but it is likely occurring, and cases may be going undetected in the region, said Dr. Beatty.

He investigated the issue in Colombia as part of an international collaboration involving the University of Antioquia, aiming to find ways to mitigate oral transmission and create a model that can be used throughout Latin America and the United States. For the Colombia study, they reviewed all cases reported to the Ministry of Health and Social Protection, and oral transmission turned out to be more common than the research group expected. “Still, I imagine that in certain areas with limited resources…there are many more cases that are not being reported.

“A myth I would like to dispel is that Chagas disease is not being transmitted in the United States,” Dr. Beatty added. He mentioned that at least 30 American states have vectors, and in Florida, it was documented that triatomines invaded homes and bit residents. In addition, 30% of these insects are infected with T cruzi. Research is underway to determine whether Floridians are becoming infected and if they are also at risk of contracting Chagas disease orally, said Dr. Beatty. “In the United States, we know very little about how many people are infected and what the infection routes are. Much more research is needed.”

Roberto Chuit, MD, PhD, a doctor in public health and an external consultant for the Pan American Health Organization (PAHO), agreed that this route of food contamination, which occurs because of vector-borne parasites, was until recently masked or hidden by the predominance of vector presence. Just as it began to gain importance as other transmission routes were controlled, “it now has extremely high importance in the Americas, as does vertical transmission,” he said.

In 2023, more than 50 years after the first description of oral transmission, the PAHO expert meeting proposed to alert health services and the broader community about the severity and potential lethality of oral Chagas disease outbreaks to elicit immediate responses and mitigation measures. The body also proposed conducting studies to provide detailed information on the contamination source and the wild vectors present in oral transmission foci.
 

Unique Clinical Manifestations

The exacerbated signs and symptoms of oral infection (see sidebar) are attributed to the high parasite loads in contaminated food and beverages. A single crushed triatomine along with a food or beverage harboring T cruzi can contain an estimated 600,000 metacyclic trypomastigotes, compared with 3000-4000 per µL when infection occurs by triatomine fecal matter. The robust systemic immune response observed in patients with acute oral Chagas disease is thought to result from more efficient transmission after penetration through the oral, pharyngeal, and gastric mucosae.
 

Seven Things to Know About Orally Transmitted Chagas Disease

1. It presents with exacerbated symptoms and rapid disease progression in immunocompetent individuals. This presentation is not common in vector-borne, congenital, or transfusion-related transmission. It can cause fulminant myocarditis and heart failure, meningoencephalitis, or potentially fatal shock due to parasitemia.

2. Most patients (71%-100%) with acute oral Chagas present with fever.

3. Electrocardiographic abnormalities, specifically ventricular depolarization alterations and pericardial involvement, are observed in most patients.

4. Facial edema, which typically affects the entire face and parts of the lips, is present in 57%-100% of patients with acute oral Chagas disease. In those with acute symptoms from vector transmission, unilateral periorbital swelling (Romaña’s sign) is more common.

5. Other notable systemic symptoms include edema of the lower extremities, myalgia, generalized lymphadenopathy, abdominal discomfort, dyspnea, vomiting, diarrhea, hepatomegaly, splenomegaly, headache, chest pain, cutaneous erythematous rash, jaundice, arthralgia, epistaxis, hematemesis, melena, and palpitations.

6. The incubation period after oral ingestion of products contaminated with Trypanosoma cruzi is approximately 3-22 days, in contrast to 4-15 days for vector-borne transmission and 8-160 days for transfusion and transplant-related transmission.

7. Patients need antiparasitic drugs immediately.
 

Thinking Epidemiologically

Dr. Chuit recalled that suspicion of food contamination should be based on epidemiology, especially in outbreaks affecting several people and in regions where Chagas vectors have been described. Sometimes, however, a single careless tourist consumes contaminated products.

“The difficulty is that many times it is not considered, and if it is not considered, the search for the parasite is not requested,” said Dr. Chuit. He added that it is common for the professional to consider Chagas disease only if viral and bacterial isolation tests are negative. Clinicians sometimes consider Chagas disease because the patient has not responded to regular treatments for other causes, such as antibiotics and hydration.

Epidemiology is important, especially when Chagas disease is diagnosed in groups or a family, because they are usually not isolated cases but outbreaks of 3-40 cases, according to Dr. Chuit. “Under these conditions, it must be quickly considered…that this parasite may be involved.”

One of the difficulties is that the source of these oral transmissions is not recognized most of the time. In general, the sources are usually foods that are more likely to be contaminated by insects or insect feces, such as orange juice or sugarcane. But in fact, any food or beverage left unattended could be contaminated by vectors or possible secretions from infected marsupial odoriferous glands.

An analysis of 32 outbreaks from 1965 to 2022 showed that the main foods involved in oral transmission were homemade fruit juices. But different vector species were identified, and the reservoirs were mainly dogs, rodents, and large American opossums (Didelphis).

The largest oral Chagas outbreak was linked to the consumption of contaminated guava juice in a primary school in Caracas, Venezuela. Nonindustrially produced açaí is a common source of orally acquired Chagas disease in Brazil. In Colombia, Chagas disease has been associated with the consumption of palm wine, sugar cane, and tangerine juice. Other oral transmission routes include consuming meat from wild animals and ingesting blood from infected armadillos, which is related to a traditional medicine practice.
 

Deadly Yet Easily Treatable

In the outbreak of 119 confirmed and suspected cases in Venezuela, 20.3% required hospitalization, and a 5-year-old child died of acute myocarditis. These percentages differ from those reported in vector transmission, which is asymptomatic in the acute phase for 95%-99% of cases or will only develop a mild febrile illness that resolves on its own.

“Not all cases will present as severe, because depending on the inoculum, there may be individuals with subclinical situations. But any food poisoning that occurs in endemic areas, where food is not properly controlled, and these street foods are associated with processes in jungle areas, raises the possibility that T cruzi is involved and should be considered as a differential diagnosis,» noted Dr. Chuit. “The treatment is highly effective, and people recover quickly.”

“The most important thing about oral transmission of Chagas is that someone infected in this way needs antiparasitic drugs immediately. We can cure them if we treat them immediately,” said Dr. Beatty, adding that treatment is sometimes delayed due to lack of access to appropriate antiparasitic drugs. “Here in the United States and in Latin America, it is quite common for healthcare professionals not to understand the differences between vector, vertical, and oral transmission. By not treating these patients, they become ill quickly.”

Dr. Beatty and Dr. Chuit declared no relevant financial conflicts of interest.

This story was translated from the Medscape Spanish edition using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication. A version of this article appeared on Medscape.com.

Thanks to decades of successful vector control strategies, vector-borne transmission of Chagas disease has significantly decreased in many regions. Oral ingestion of Trypanosoma cruzi through contaminated food and beverages, however, is increasing. Unlike vector transmission, oral transmission of Chagas disease entails high lethality in pediatric and adult populations.

“The oral transmission of Chagas disease is becoming a much more recognized route, and it is crucial to understand that people can die from this type of transmission,” Norman L. Beatty, MD, assistant professor of infectious diseases and global medicine at the University of Florida College of Medicine in Gainesville, Florida, told this news organization. Dr. Beatty is the lead author of a recent article on the subject.

In regions where the parasite circulates in the environment, people are consuming foods, fruit juices, and possibly wild animal meat that may be contaminated. “As we experience changes in our environment and in the way we consume food, it is crucial to consider how food preparation is carried out in areas where T cruzi transmission occurs in the environment,” said Dr. Beatty. “And as organic farming methods without insecticides become increasingly common, more research is needed in these areas, both in Latin America and in the United States, to understand if oral transmission of T cruzi is occurring.”

In the Amazon basin, foodborne transmission is already the leading cause of acute Chagas disease. It has been described in Argentina, Bolivia, Brazil, Colombia, Ecuador, French Guiana, and Venezuela.

Dr. Beatty’s colleagues recently treated a Brazilian patient at the hospital in Florida. “He came to our hospital very ill, with acute myocarditis after consuming contaminated açaí.” Clarifying that there is widespread awareness about oral transmission in Brazil, he stated, “We are concerned that it may not be recognized in other areas of Latin America.”

Mexico and regions of Central America have little to no information on oral transmission, but it is likely occurring, and cases may be going undetected in the region, said Dr. Beatty.

He investigated the issue in Colombia as part of an international collaboration involving the University of Antioquia, aiming to find ways to mitigate oral transmission and create a model that can be used throughout Latin America and the United States. For the Colombia study, they reviewed all cases reported to the Ministry of Health and Social Protection, and oral transmission turned out to be more common than the research group expected. “Still, I imagine that in certain areas with limited resources…there are many more cases that are not being reported.

“A myth I would like to dispel is that Chagas disease is not being transmitted in the United States,” Dr. Beatty added. He mentioned that at least 30 American states have vectors, and in Florida, it was documented that triatomines invaded homes and bit residents. In addition, 30% of these insects are infected with T cruzi. Research is underway to determine whether Floridians are becoming infected and if they are also at risk of contracting Chagas disease orally, said Dr. Beatty. “In the United States, we know very little about how many people are infected and what the infection routes are. Much more research is needed.”

Roberto Chuit, MD, PhD, a doctor in public health and an external consultant for the Pan American Health Organization (PAHO), agreed that this route of food contamination, which occurs because of vector-borne parasites, was until recently masked or hidden by the predominance of vector presence. Just as it began to gain importance as other transmission routes were controlled, “it now has extremely high importance in the Americas, as does vertical transmission,” he said.

In 2023, more than 50 years after the first description of oral transmission, the PAHO expert meeting proposed to alert health services and the broader community about the severity and potential lethality of oral Chagas disease outbreaks to elicit immediate responses and mitigation measures. The body also proposed conducting studies to provide detailed information on the contamination source and the wild vectors present in oral transmission foci.
 

Unique Clinical Manifestations

The exacerbated signs and symptoms of oral infection (see sidebar) are attributed to the high parasite loads in contaminated food and beverages. A single crushed triatomine along with a food or beverage harboring T cruzi can contain an estimated 600,000 metacyclic trypomastigotes, compared with 3000-4000 per µL when infection occurs by triatomine fecal matter. The robust systemic immune response observed in patients with acute oral Chagas disease is thought to result from more efficient transmission after penetration through the oral, pharyngeal, and gastric mucosae.
 

Seven Things to Know About Orally Transmitted Chagas Disease

1. It presents with exacerbated symptoms and rapid disease progression in immunocompetent individuals. This presentation is not common in vector-borne, congenital, or transfusion-related transmission. It can cause fulminant myocarditis and heart failure, meningoencephalitis, or potentially fatal shock due to parasitemia.

2. Most patients (71%-100%) with acute oral Chagas present with fever.

3. Electrocardiographic abnormalities, specifically ventricular depolarization alterations and pericardial involvement, are observed in most patients.

4. Facial edema, which typically affects the entire face and parts of the lips, is present in 57%-100% of patients with acute oral Chagas disease. In those with acute symptoms from vector transmission, unilateral periorbital swelling (Romaña’s sign) is more common.

5. Other notable systemic symptoms include edema of the lower extremities, myalgia, generalized lymphadenopathy, abdominal discomfort, dyspnea, vomiting, diarrhea, hepatomegaly, splenomegaly, headache, chest pain, cutaneous erythematous rash, jaundice, arthralgia, epistaxis, hematemesis, melena, and palpitations.

6. The incubation period after oral ingestion of products contaminated with Trypanosoma cruzi is approximately 3-22 days, in contrast to 4-15 days for vector-borne transmission and 8-160 days for transfusion and transplant-related transmission.

7. Patients need antiparasitic drugs immediately.
 

Thinking Epidemiologically

Dr. Chuit recalled that suspicion of food contamination should be based on epidemiology, especially in outbreaks affecting several people and in regions where Chagas vectors have been described. Sometimes, however, a single careless tourist consumes contaminated products.

“The difficulty is that many times it is not considered, and if it is not considered, the search for the parasite is not requested,” said Dr. Chuit. He added that it is common for the professional to consider Chagas disease only if viral and bacterial isolation tests are negative. Clinicians sometimes consider Chagas disease because the patient has not responded to regular treatments for other causes, such as antibiotics and hydration.

Epidemiology is important, especially when Chagas disease is diagnosed in groups or a family, because they are usually not isolated cases but outbreaks of 3-40 cases, according to Dr. Chuit. “Under these conditions, it must be quickly considered…that this parasite may be involved.”

One of the difficulties is that the source of these oral transmissions is not recognized most of the time. In general, the sources are usually foods that are more likely to be contaminated by insects or insect feces, such as orange juice or sugarcane. But in fact, any food or beverage left unattended could be contaminated by vectors or possible secretions from infected marsupial odoriferous glands.

An analysis of 32 outbreaks from 1965 to 2022 showed that the main foods involved in oral transmission were homemade fruit juices. But different vector species were identified, and the reservoirs were mainly dogs, rodents, and large American opossums (Didelphis).

The largest oral Chagas outbreak was linked to the consumption of contaminated guava juice in a primary school in Caracas, Venezuela. Nonindustrially produced açaí is a common source of orally acquired Chagas disease in Brazil. In Colombia, Chagas disease has been associated with the consumption of palm wine, sugar cane, and tangerine juice. Other oral transmission routes include consuming meat from wild animals and ingesting blood from infected armadillos, which is related to a traditional medicine practice.
 

Deadly Yet Easily Treatable

In the outbreak of 119 confirmed and suspected cases in Venezuela, 20.3% required hospitalization, and a 5-year-old child died of acute myocarditis. These percentages differ from those reported in vector transmission, which is asymptomatic in the acute phase for 95%-99% of cases or will only develop a mild febrile illness that resolves on its own.

“Not all cases will present as severe, because depending on the inoculum, there may be individuals with subclinical situations. But any food poisoning that occurs in endemic areas, where food is not properly controlled, and these street foods are associated with processes in jungle areas, raises the possibility that T cruzi is involved and should be considered as a differential diagnosis,» noted Dr. Chuit. “The treatment is highly effective, and people recover quickly.”

“The most important thing about oral transmission of Chagas is that someone infected in this way needs antiparasitic drugs immediately. We can cure them if we treat them immediately,” said Dr. Beatty, adding that treatment is sometimes delayed due to lack of access to appropriate antiparasitic drugs. “Here in the United States and in Latin America, it is quite common for healthcare professionals not to understand the differences between vector, vertical, and oral transmission. By not treating these patients, they become ill quickly.”

Dr. Beatty and Dr. Chuit declared no relevant financial conflicts of interest.

This story was translated from the Medscape Spanish edition using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication. A version of this article appeared on Medscape.com.

Thanks to decades of successful vector control strategies, vector-borne transmission of Chagas disease has significantly decreased in many regions. Oral ingestion of Trypanosoma cruzi through contaminated food and beverages, however, is increasing. Unlike vector transmission, oral transmission of Chagas disease entails high lethality in pediatric and adult populations.

“The oral transmission of Chagas disease is becoming a much more recognized route, and it is crucial to understand that people can die from this type of transmission,” Norman L. Beatty, MD, assistant professor of infectious diseases and global medicine at the University of Florida College of Medicine in Gainesville, Florida, told this news organization. Dr. Beatty is the lead author of a recent article on the subject.

In regions where the parasite circulates in the environment, people are consuming foods, fruit juices, and possibly wild animal meat that may be contaminated. “As we experience changes in our environment and in the way we consume food, it is crucial to consider how food preparation is carried out in areas where T cruzi transmission occurs in the environment,” said Dr. Beatty. “And as organic farming methods without insecticides become increasingly common, more research is needed in these areas, both in Latin America and in the United States, to understand if oral transmission of T cruzi is occurring.”

In the Amazon basin, foodborne transmission is already the leading cause of acute Chagas disease. It has been described in Argentina, Bolivia, Brazil, Colombia, Ecuador, French Guiana, and Venezuela.

Dr. Beatty’s colleagues recently treated a Brazilian patient at the hospital in Florida. “He came to our hospital very ill, with acute myocarditis after consuming contaminated açaí.” Clarifying that there is widespread awareness about oral transmission in Brazil, he stated, “We are concerned that it may not be recognized in other areas of Latin America.”

Mexico and regions of Central America have little to no information on oral transmission, but it is likely occurring, and cases may be going undetected in the region, said Dr. Beatty.

He investigated the issue in Colombia as part of an international collaboration involving the University of Antioquia, aiming to find ways to mitigate oral transmission and create a model that can be used throughout Latin America and the United States. For the Colombia study, they reviewed all cases reported to the Ministry of Health and Social Protection, and oral transmission turned out to be more common than the research group expected. “Still, I imagine that in certain areas with limited resources…there are many more cases that are not being reported.

“A myth I would like to dispel is that Chagas disease is not being transmitted in the United States,” Dr. Beatty added. He mentioned that at least 30 American states have vectors, and in Florida, it was documented that triatomines invaded homes and bit residents. In addition, 30% of these insects are infected with T cruzi. Research is underway to determine whether Floridians are becoming infected and if they are also at risk of contracting Chagas disease orally, said Dr. Beatty. “In the United States, we know very little about how many people are infected and what the infection routes are. Much more research is needed.”

Roberto Chuit, MD, PhD, a doctor in public health and an external consultant for the Pan American Health Organization (PAHO), agreed that this route of food contamination, which occurs because of vector-borne parasites, was until recently masked or hidden by the predominance of vector presence. Just as it began to gain importance as other transmission routes were controlled, “it now has extremely high importance in the Americas, as does vertical transmission,” he said.

In 2023, more than 50 years after the first description of oral transmission, the PAHO expert meeting proposed to alert health services and the broader community about the severity and potential lethality of oral Chagas disease outbreaks to elicit immediate responses and mitigation measures. The body also proposed conducting studies to provide detailed information on the contamination source and the wild vectors present in oral transmission foci.
 

Unique Clinical Manifestations

The exacerbated signs and symptoms of oral infection (see sidebar) are attributed to the high parasite loads in contaminated food and beverages. A single crushed triatomine along with a food or beverage harboring T cruzi can contain an estimated 600,000 metacyclic trypomastigotes, compared with 3000-4000 per µL when infection occurs by triatomine fecal matter. The robust systemic immune response observed in patients with acute oral Chagas disease is thought to result from more efficient transmission after penetration through the oral, pharyngeal, and gastric mucosae.
 

Seven Things to Know About Orally Transmitted Chagas Disease

1. It presents with exacerbated symptoms and rapid disease progression in immunocompetent individuals. This presentation is not common in vector-borne, congenital, or transfusion-related transmission. It can cause fulminant myocarditis and heart failure, meningoencephalitis, or potentially fatal shock due to parasitemia.

2. Most patients (71%-100%) with acute oral Chagas present with fever.

3. Electrocardiographic abnormalities, specifically ventricular depolarization alterations and pericardial involvement, are observed in most patients.

4. Facial edema, which typically affects the entire face and parts of the lips, is present in 57%-100% of patients with acute oral Chagas disease. In those with acute symptoms from vector transmission, unilateral periorbital swelling (Romaña’s sign) is more common.

5. Other notable systemic symptoms include edema of the lower extremities, myalgia, generalized lymphadenopathy, abdominal discomfort, dyspnea, vomiting, diarrhea, hepatomegaly, splenomegaly, headache, chest pain, cutaneous erythematous rash, jaundice, arthralgia, epistaxis, hematemesis, melena, and palpitations.

6. The incubation period after oral ingestion of products contaminated with Trypanosoma cruzi is approximately 3-22 days, in contrast to 4-15 days for vector-borne transmission and 8-160 days for transfusion and transplant-related transmission.

7. Patients need antiparasitic drugs immediately.
 

Thinking Epidemiologically

Dr. Chuit recalled that suspicion of food contamination should be based on epidemiology, especially in outbreaks affecting several people and in regions where Chagas vectors have been described. Sometimes, however, a single careless tourist consumes contaminated products.

“The difficulty is that many times it is not considered, and if it is not considered, the search for the parasite is not requested,” said Dr. Chuit. He added that it is common for the professional to consider Chagas disease only if viral and bacterial isolation tests are negative. Clinicians sometimes consider Chagas disease because the patient has not responded to regular treatments for other causes, such as antibiotics and hydration.

Epidemiology is important, especially when Chagas disease is diagnosed in groups or a family, because they are usually not isolated cases but outbreaks of 3-40 cases, according to Dr. Chuit. “Under these conditions, it must be quickly considered…that this parasite may be involved.”

One of the difficulties is that the source of these oral transmissions is not recognized most of the time. In general, the sources are usually foods that are more likely to be contaminated by insects or insect feces, such as orange juice or sugarcane. But in fact, any food or beverage left unattended could be contaminated by vectors or possible secretions from infected marsupial odoriferous glands.

An analysis of 32 outbreaks from 1965 to 2022 showed that the main foods involved in oral transmission were homemade fruit juices. But different vector species were identified, and the reservoirs were mainly dogs, rodents, and large American opossums (Didelphis).

The largest oral Chagas outbreak was linked to the consumption of contaminated guava juice in a primary school in Caracas, Venezuela. Nonindustrially produced açaí is a common source of orally acquired Chagas disease in Brazil. In Colombia, Chagas disease has been associated with the consumption of palm wine, sugar cane, and tangerine juice. Other oral transmission routes include consuming meat from wild animals and ingesting blood from infected armadillos, which is related to a traditional medicine practice.
 

Deadly Yet Easily Treatable

In the outbreak of 119 confirmed and suspected cases in Venezuela, 20.3% required hospitalization, and a 5-year-old child died of acute myocarditis. These percentages differ from those reported in vector transmission, which is asymptomatic in the acute phase for 95%-99% of cases or will only develop a mild febrile illness that resolves on its own.

“Not all cases will present as severe, because depending on the inoculum, there may be individuals with subclinical situations. But any food poisoning that occurs in endemic areas, where food is not properly controlled, and these street foods are associated with processes in jungle areas, raises the possibility that T cruzi is involved and should be considered as a differential diagnosis,» noted Dr. Chuit. “The treatment is highly effective, and people recover quickly.”

“The most important thing about oral transmission of Chagas is that someone infected in this way needs antiparasitic drugs immediately. We can cure them if we treat them immediately,” said Dr. Beatty, adding that treatment is sometimes delayed due to lack of access to appropriate antiparasitic drugs. “Here in the United States and in Latin America, it is quite common for healthcare professionals not to understand the differences between vector, vertical, and oral transmission. By not treating these patients, they become ill quickly.”

Dr. Beatty and Dr. Chuit declared no relevant financial conflicts of interest.

This story was translated from the Medscape Spanish edition using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication. A version of this article appeared on Medscape.com.

Non–Lyme disease, tick-borne illnesses — such as spotted fever group rickettsiosis (SFGR), ehrlichiosis, and alpha-gal syndrome (AGS) — are emerging public health threats, but whether prior tick exposures are responsible for long-term complications, such as musculoskeletal symptoms or osteoarthritis, has been unclear.

Many patients attribute their nonspecific long-term symptoms, such as musculoskeletal pain, to previous illnesses from tick bites, note authors of a study published in JAMA Network Open. But the researchers, led by Diana L. Zychowski, MD, MPH, with the Division of Infectious Diseases at the University of North Carolina at Chapel Hill, found that Ehrlichia or Rickettsia seropositivity was not associated with chronic musculoskeletal symptoms, though they write that “further investigation into the pathogenesis of [alpha-gal] syndrome is needed.”
 

Tick-Borne Illness Cases Multiplying

Cases of tick-borne illness (TBD) in the United States have multiplied in recent years. More than 50,000 cases of TBD in the United States were reported in 2019, which doubled the number of cases over the previous 2 decades, the authors note.

Most of the cases are Lyme disease, but others — including SFGR and ehrlichiosis — represent an important public health threat, especially in southeastern states, the authors write. Cases of ehrlichiosis, for example, transmitted by the lone star tick, soared more than 10-fold since 2000.

The goal of this study was to evaluate whether there was an association between prior exposure to TBDs endemic to the southeastern United States and chronic musculoskeletal symptoms and radiographic measures of osteoarthritis.

Researchers analyzed 488 blood samples from the fourth visit (2017-2018) of the Johnston County Osteoarthritis (JoCo OA) project, an ongoing population-based study in Johnston County, North Carolina. JoCo OA participants include noninstitutionalized White and Black Johnston County residents 45 years old or older with osteoarthritis.

They measured seroprevalence of Rickettsia- and Ehrlichia-specific immunoglobulin G (IgG) as well as alpha-gal immunoglobulin E (IgE) in patient samples. Only alpha-gal IgE was linked in the study with knee pain, aching, or stiffness. Antibodies to Rickettsia, Ehrlichia, and alpha-gal were not associated with radiographic, symptomatic knee osteoarthritis.

“To our knowledge,” the authors write, “this study was the first population-based seroprevalence study of SFGR, Ehrlichia, and [alpha]-gal.”

The study also found a high prevalence of TBD exposure in the cohort. More than a third (36.5%) had either an alpha-gal IgE level greater than 0.1 IU/mL, a positive test for SFGR IgG antibodies, or a positive test for Ehrlichia IgG antibodies.

Given that not every tick carries an infectious pathogen, the findings show human-tick interactions are common, they write.

“These findings suggest that substantial investment is required to examine the pathogenesis of these TBDs and interventions to reduce human-tick interactions,” the authors conclude.

This study was funded by a Creativity Hub Award from the University of North Carolina Office of the Vice Chancellor for Research. The JoCo OA project is supported in part by grants from the Association of Schools of Public Health/Centers for Disease Control and Prevention (CDC); and grants from the National Institute of Arthritis and Musculoskeletal and Skin Diseases. Authors reported grants from the National Institutes of Health, the CDC, and several pharmaceutical companies.

Non–Lyme disease, tick-borne illnesses — such as spotted fever group rickettsiosis (SFGR), ehrlichiosis, and alpha-gal syndrome (AGS) — are emerging public health threats, but whether prior tick exposures are responsible for long-term complications, such as musculoskeletal symptoms or osteoarthritis, has been unclear.

Many patients attribute their nonspecific long-term symptoms, such as musculoskeletal pain, to previous illnesses from tick bites, note authors of a study published in JAMA Network Open. But the researchers, led by Diana L. Zychowski, MD, MPH, with the Division of Infectious Diseases at the University of North Carolina at Chapel Hill, found that Ehrlichia or Rickettsia seropositivity was not associated with chronic musculoskeletal symptoms, though they write that “further investigation into the pathogenesis of [alpha-gal] syndrome is needed.”
 

Tick-Borne Illness Cases Multiplying

Cases of tick-borne illness (TBD) in the United States have multiplied in recent years. More than 50,000 cases of TBD in the United States were reported in 2019, which doubled the number of cases over the previous 2 decades, the authors note.

Most of the cases are Lyme disease, but others — including SFGR and ehrlichiosis — represent an important public health threat, especially in southeastern states, the authors write. Cases of ehrlichiosis, for example, transmitted by the lone star tick, soared more than 10-fold since 2000.

The goal of this study was to evaluate whether there was an association between prior exposure to TBDs endemic to the southeastern United States and chronic musculoskeletal symptoms and radiographic measures of osteoarthritis.

Researchers analyzed 488 blood samples from the fourth visit (2017-2018) of the Johnston County Osteoarthritis (JoCo OA) project, an ongoing population-based study in Johnston County, North Carolina. JoCo OA participants include noninstitutionalized White and Black Johnston County residents 45 years old or older with osteoarthritis.

They measured seroprevalence of Rickettsia- and Ehrlichia-specific immunoglobulin G (IgG) as well as alpha-gal immunoglobulin E (IgE) in patient samples. Only alpha-gal IgE was linked in the study with knee pain, aching, or stiffness. Antibodies to Rickettsia, Ehrlichia, and alpha-gal were not associated with radiographic, symptomatic knee osteoarthritis.

“To our knowledge,” the authors write, “this study was the first population-based seroprevalence study of SFGR, Ehrlichia, and [alpha]-gal.”

The study also found a high prevalence of TBD exposure in the cohort. More than a third (36.5%) had either an alpha-gal IgE level greater than 0.1 IU/mL, a positive test for SFGR IgG antibodies, or a positive test for Ehrlichia IgG antibodies.

Given that not every tick carries an infectious pathogen, the findings show human-tick interactions are common, they write.

“These findings suggest that substantial investment is required to examine the pathogenesis of these TBDs and interventions to reduce human-tick interactions,” the authors conclude.

This study was funded by a Creativity Hub Award from the University of North Carolina Office of the Vice Chancellor for Research. The JoCo OA project is supported in part by grants from the Association of Schools of Public Health/Centers for Disease Control and Prevention (CDC); and grants from the National Institute of Arthritis and Musculoskeletal and Skin Diseases. Authors reported grants from the National Institutes of Health, the CDC, and several pharmaceutical companies.

Non–Lyme disease, tick-borne illnesses — such as spotted fever group rickettsiosis (SFGR), ehrlichiosis, and alpha-gal syndrome (AGS) — are emerging public health threats, but whether prior tick exposures are responsible for long-term complications, such as musculoskeletal symptoms or osteoarthritis, has been unclear.

Many patients attribute their nonspecific long-term symptoms, such as musculoskeletal pain, to previous illnesses from tick bites, note authors of a study published in JAMA Network Open. But the researchers, led by Diana L. Zychowski, MD, MPH, with the Division of Infectious Diseases at the University of North Carolina at Chapel Hill, found that Ehrlichia or Rickettsia seropositivity was not associated with chronic musculoskeletal symptoms, though they write that “further investigation into the pathogenesis of [alpha-gal] syndrome is needed.”
 

Tick-Borne Illness Cases Multiplying

Cases of tick-borne illness (TBD) in the United States have multiplied in recent years. More than 50,000 cases of TBD in the United States were reported in 2019, which doubled the number of cases over the previous 2 decades, the authors note.

Most of the cases are Lyme disease, but others — including SFGR and ehrlichiosis — represent an important public health threat, especially in southeastern states, the authors write. Cases of ehrlichiosis, for example, transmitted by the lone star tick, soared more than 10-fold since 2000.

The goal of this study was to evaluate whether there was an association between prior exposure to TBDs endemic to the southeastern United States and chronic musculoskeletal symptoms and radiographic measures of osteoarthritis.

Researchers analyzed 488 blood samples from the fourth visit (2017-2018) of the Johnston County Osteoarthritis (JoCo OA) project, an ongoing population-based study in Johnston County, North Carolina. JoCo OA participants include noninstitutionalized White and Black Johnston County residents 45 years old or older with osteoarthritis.

They measured seroprevalence of Rickettsia- and Ehrlichia-specific immunoglobulin G (IgG) as well as alpha-gal immunoglobulin E (IgE) in patient samples. Only alpha-gal IgE was linked in the study with knee pain, aching, or stiffness. Antibodies to Rickettsia, Ehrlichia, and alpha-gal were not associated with radiographic, symptomatic knee osteoarthritis.

“To our knowledge,” the authors write, “this study was the first population-based seroprevalence study of SFGR, Ehrlichia, and [alpha]-gal.”

The study also found a high prevalence of TBD exposure in the cohort. More than a third (36.5%) had either an alpha-gal IgE level greater than 0.1 IU/mL, a positive test for SFGR IgG antibodies, or a positive test for Ehrlichia IgG antibodies.

Given that not every tick carries an infectious pathogen, the findings show human-tick interactions are common, they write.

“These findings suggest that substantial investment is required to examine the pathogenesis of these TBDs and interventions to reduce human-tick interactions,” the authors conclude.

This study was funded by a Creativity Hub Award from the University of North Carolina Office of the Vice Chancellor for Research. The JoCo OA project is supported in part by grants from the Association of Schools of Public Health/Centers for Disease Control and Prevention (CDC); and grants from the National Institute of Arthritis and Musculoskeletal and Skin Diseases. Authors reported grants from the National Institutes of Health, the CDC, and several pharmaceutical companies.

When they started the open biopsy, surgeons didn’t know what they were going to find, but they certainly didn’t expect this.

The stringlike worm was five-sixteenths of an inch long, was alive, and wiggled.

“It stunned everyone in that operating theater,” Sanjaya Senanayake, MBBS, an associate professor of infectious disease at Australian National University, Canberra, and senior author of the case report, said in an interview. “When you operate on a brain, you don’t expect to find anything alive.”

The parasitic worm was about half the width of a dime. Helminths like it can usually be seen with the naked eye but are often found in the intestines after being transmitted by soil and infecting the gastrointestinal tract. But this one made it into a woman’s brain in a first-of-its-kind case reported in the journal Emerging Infectious Diseases).

“We weren’t suspecting a worm at all,” Dr. Senanayake said. “There was something abnormal there. Was it going to be granulomatous lesion? Was it going to be cancer? Who knows, but it needed to be biopsied, and a worm was the last thing at the back of anyone’s mind,” he said.
 

A year of inexplicable symptoms

The 64-year-old woman was diagnosed with pneumonia and had a high white blood cell count, low hemoglobin, high platelets, and a very high C-reactive protein of 102 mg/L.

She hadn’t fully recovered from her illness when the abdominal pain and diarrhea started. And then she had a dry cough and night sweats.

After 3 weeks of discomfort, she was admitted to the hospital. She had a history of diabetes, hypothyroidism, and depression, and doctors began looking for answers to her acute illness.

They tested for autoimmune diseases and parasitic infections and prescribed prednisolone to help ease symptoms.

But 3 weeks later, her fever and cough persisted, and she was readmitted to the hospital. Doctors ordered more tests, and her eosinophils were still high, plus there were lesions on her liver, spleen, and lungs.

But tests were negative for bacterial, fungal, and mycobacterial cultures. Her stools showed no evidence of parasites.

She was prescribed mycophenolate and then ivermectin in case her tests for roundworm were a false negative. Doctors suspected Strongyloides, but lesions remained on her spleen even as the liver and lung lesions improved.

Reducing the prednisolone dose affected respiratory symptoms, so by January 2022, a year after initial symptoms began, the medical team added the monoclonal antibody mepolizumab. But her symptoms worsened, and she developed forgetfulness and more depression.

After a brain MRI revealed a right frontal lobe lesion, the team recommended an open biopsy and discovered the worm. The specimen was Ophidascaris robertsi, the intestinal roundworm typically of the carpet python. Never before seen in a human, the only other animals in its life cycle are small marsupials or mammals consumed by pythons.
 

A snake’s bug

Although this is the first case of an Ophidascaris infection in a human, other cases could occur, warn the doctors in their case report.

The best guess for how the patient contracted the infection was by inadvertently consuming larval eggs on wild vegetation that she collected near her home to eat. She lived near a lake known to be home to carpet pythons, so the eggs could have been on the plants she collected or on her hands or kitchen equipment.

“If you’re foraging or using native grasses or plants in recipes, it would be a good idea to cook those instead of having a salad,” Dr. Senanayake said. “That would make the chance of getting something really rare even less likely.”

It’s unclear how or why the worm, which usually stays in the gut, made its way into the patient’s brain, but her long course of immunosuppressing drugs may have played a role, the team points out. “If the normal immune barriers are reduced, then it’s easier for the parasite to move around between organ systems,” Dr. Senanayake said.

Doctors also wondered if she may have been getting re-infected when she went home between hospital admissions. After removing the worm, she received 4 weeks of treatment with albendazole to eliminate any other possible larvae in other organs, especially since Ophidascaris larvae have been known to survive for long periods – more than 4 years in laboratory rats. “The hope is that she’s been cured of this parasitic infection,” Dr. Senanayake said.

As people around the world contend with the global COVID pandemic, they might not realize that new infections are arising around the world every year, he explained.
 

Novel parasitic infections

“The reality is that 30 new infections appeared in the last 30 years, and three-quarters of them are zoonotic, animal infections spilling over into the human world,” Dr. Senanayake said.

Though some of that number is the result of improved surveillance and diagnostics, a real increase has been occurring as human settlements continue expanding.

“This is just a reflection of how burgeoning human populations are encroaching upon animal habitats, and we’re getting more interactions between humans and wild animals, domestic animals and wild animals, and humans and natural flora, which is increasing the risk of this type of infection being recognized,” he explained.

The Ophidascaris worm found in this instance is in other snake species in different continents around the world, too. “Awareness of this case will hopefully lead to the diagnosis and treatment of other cases,” Dr. Senanayake added.

Though it’s certainly surprising to find this particular parasite in a human, finding a zoonotic organism in a person isn’t that strange, according to Janet Foley, DVM, PhD, a professor of veterinary medicine at the University of California, Davis. This is especially true if the usual host is closely related to humans, like primates, or spends a lot of time around them, like rats.

“There are still a lot of parasites and diseases out there in wildlife that haven’t been discovered, and we don’t know the risk,” said Dr. Foley. “But still, the risk would have to be low, generally, or we would see more human cases.”

In the United States, the roundworm common in raccoon feces is Baylisascaris procyonis and can be dangerous for people. “There have been deaths in people exposed to these worms, which do seem to prefer to travel to a human brain,” Dr. Foley said.

A 2016 Centers for Disease Control and Prevention report described seven U.S. cases identified between May 2013 and December 2015, including six that caused central nervous system disease. Another case report in 2018 involved a toddler who had eaten dirt and animal feces in his backyard.

And this past June, an Emerging Infectious Diseases case report described a B. procyonis infection in a 7-year-old with autism spectrum disorder and a history of pica. He had put material in his mouth from the ground near a tree where epidemiologists later found raccoon feces.

Still, Dr. Senanayake cautions against people jumping to conclusions about parasitic infections when they experience symptoms that aren’t otherwise immediately explainable.

The typical person who develops forgetfulness, depression, and a fever probably doesn’t have a worm in their brain or need an immediate MRI, he pointed out. “There may be other cases out there, but common things happen commonly, and this is likely to be rare,” Dr. Senanayake said.

This case demonstrates the challenge in picking a course of treatment when the differential diagnoses for hypereosinophilic syndromes is so broad.
 

Tricky hypereosinophilic syndromes

One of those differentials for the syndromes is parasitic infections, for which treatment would be antiparasitic agents, but another differential is an autoimmune condition that would call for immunosuppression.

“Obviously, as with this case, you don’t want to give someone immunosuppressive treatment if they’ve got a parasite, so you want to look really hard for a parasite before you start them on immunosuppressive treatment for an immunological condition,” Dr. Senanayake said.

But all the blood tests for different antibodies came back negative for parasites, “and this parasite was simply difficult to find until they pulled it from her brain,” he said.

Infectious disease physicians are always looking for the unusual and exotic, Dr. Senanayake explained. But it’s important to exclude the common, easy things first, he added. It’s after exhausting all the likely culprits that “you have to start really thinking laterally and putting resources into unusual tests.”

A version of this article first appeared on Medscape.com.

When they started the open biopsy, surgeons didn’t know what they were going to find, but they certainly didn’t expect this.

The stringlike worm was five-sixteenths of an inch long, was alive, and wiggled.

“It stunned everyone in that operating theater,” Sanjaya Senanayake, MBBS, an associate professor of infectious disease at Australian National University, Canberra, and senior author of the case report, said in an interview. “When you operate on a brain, you don’t expect to find anything alive.”

The parasitic worm was about half the width of a dime. Helminths like it can usually be seen with the naked eye but are often found in the intestines after being transmitted by soil and infecting the gastrointestinal tract. But this one made it into a woman’s brain in a first-of-its-kind case reported in the journal Emerging Infectious Diseases).

“We weren’t suspecting a worm at all,” Dr. Senanayake said. “There was something abnormal there. Was it going to be granulomatous lesion? Was it going to be cancer? Who knows, but it needed to be biopsied, and a worm was the last thing at the back of anyone’s mind,” he said.
 

A year of inexplicable symptoms

The 64-year-old woman was diagnosed with pneumonia and had a high white blood cell count, low hemoglobin, high platelets, and a very high C-reactive protein of 102 mg/L.

She hadn’t fully recovered from her illness when the abdominal pain and diarrhea started. And then she had a dry cough and night sweats.

After 3 weeks of discomfort, she was admitted to the hospital. She had a history of diabetes, hypothyroidism, and depression, and doctors began looking for answers to her acute illness.

They tested for autoimmune diseases and parasitic infections and prescribed prednisolone to help ease symptoms.

But 3 weeks later, her fever and cough persisted, and she was readmitted to the hospital. Doctors ordered more tests, and her eosinophils were still high, plus there were lesions on her liver, spleen, and lungs.

But tests were negative for bacterial, fungal, and mycobacterial cultures. Her stools showed no evidence of parasites.

She was prescribed mycophenolate and then ivermectin in case her tests for roundworm were a false negative. Doctors suspected Strongyloides, but lesions remained on her spleen even as the liver and lung lesions improved.

Reducing the prednisolone dose affected respiratory symptoms, so by January 2022, a year after initial symptoms began, the medical team added the monoclonal antibody mepolizumab. But her symptoms worsened, and she developed forgetfulness and more depression.

After a brain MRI revealed a right frontal lobe lesion, the team recommended an open biopsy and discovered the worm. The specimen was Ophidascaris robertsi, the intestinal roundworm typically of the carpet python. Never before seen in a human, the only other animals in its life cycle are small marsupials or mammals consumed by pythons.
 

A snake’s bug

Although this is the first case of an Ophidascaris infection in a human, other cases could occur, warn the doctors in their case report.

The best guess for how the patient contracted the infection was by inadvertently consuming larval eggs on wild vegetation that she collected near her home to eat. She lived near a lake known to be home to carpet pythons, so the eggs could have been on the plants she collected or on her hands or kitchen equipment.

“If you’re foraging or using native grasses or plants in recipes, it would be a good idea to cook those instead of having a salad,” Dr. Senanayake said. “That would make the chance of getting something really rare even less likely.”

It’s unclear how or why the worm, which usually stays in the gut, made its way into the patient’s brain, but her long course of immunosuppressing drugs may have played a role, the team points out. “If the normal immune barriers are reduced, then it’s easier for the parasite to move around between organ systems,” Dr. Senanayake said.

Doctors also wondered if she may have been getting re-infected when she went home between hospital admissions. After removing the worm, she received 4 weeks of treatment with albendazole to eliminate any other possible larvae in other organs, especially since Ophidascaris larvae have been known to survive for long periods – more than 4 years in laboratory rats. “The hope is that she’s been cured of this parasitic infection,” Dr. Senanayake said.

As people around the world contend with the global COVID pandemic, they might not realize that new infections are arising around the world every year, he explained.
 

Novel parasitic infections

“The reality is that 30 new infections appeared in the last 30 years, and three-quarters of them are zoonotic, animal infections spilling over into the human world,” Dr. Senanayake said.

Though some of that number is the result of improved surveillance and diagnostics, a real increase has been occurring as human settlements continue expanding.

“This is just a reflection of how burgeoning human populations are encroaching upon animal habitats, and we’re getting more interactions between humans and wild animals, domestic animals and wild animals, and humans and natural flora, which is increasing the risk of this type of infection being recognized,” he explained.

The Ophidascaris worm found in this instance is in other snake species in different continents around the world, too. “Awareness of this case will hopefully lead to the diagnosis and treatment of other cases,” Dr. Senanayake added.

Though it’s certainly surprising to find this particular parasite in a human, finding a zoonotic organism in a person isn’t that strange, according to Janet Foley, DVM, PhD, a professor of veterinary medicine at the University of California, Davis. This is especially true if the usual host is closely related to humans, like primates, or spends a lot of time around them, like rats.

“There are still a lot of parasites and diseases out there in wildlife that haven’t been discovered, and we don’t know the risk,” said Dr. Foley. “But still, the risk would have to be low, generally, or we would see more human cases.”

In the United States, the roundworm common in raccoon feces is Baylisascaris procyonis and can be dangerous for people. “There have been deaths in people exposed to these worms, which do seem to prefer to travel to a human brain,” Dr. Foley said.

A 2016 Centers for Disease Control and Prevention report described seven U.S. cases identified between May 2013 and December 2015, including six that caused central nervous system disease. Another case report in 2018 involved a toddler who had eaten dirt and animal feces in his backyard.

And this past June, an Emerging Infectious Diseases case report described a B. procyonis infection in a 7-year-old with autism spectrum disorder and a history of pica. He had put material in his mouth from the ground near a tree where epidemiologists later found raccoon feces.

Still, Dr. Senanayake cautions against people jumping to conclusions about parasitic infections when they experience symptoms that aren’t otherwise immediately explainable.

The typical person who develops forgetfulness, depression, and a fever probably doesn’t have a worm in their brain or need an immediate MRI, he pointed out. “There may be other cases out there, but common things happen commonly, and this is likely to be rare,” Dr. Senanayake said.

This case demonstrates the challenge in picking a course of treatment when the differential diagnoses for hypereosinophilic syndromes is so broad.
 

Tricky hypereosinophilic syndromes

One of those differentials for the syndromes is parasitic infections, for which treatment would be antiparasitic agents, but another differential is an autoimmune condition that would call for immunosuppression.

“Obviously, as with this case, you don’t want to give someone immunosuppressive treatment if they’ve got a parasite, so you want to look really hard for a parasite before you start them on immunosuppressive treatment for an immunological condition,” Dr. Senanayake said.

But all the blood tests for different antibodies came back negative for parasites, “and this parasite was simply difficult to find until they pulled it from her brain,” he said.

Infectious disease physicians are always looking for the unusual and exotic, Dr. Senanayake explained. But it’s important to exclude the common, easy things first, he added. It’s after exhausting all the likely culprits that “you have to start really thinking laterally and putting resources into unusual tests.”

A version of this article first appeared on Medscape.com.

When they started the open biopsy, surgeons didn’t know what they were going to find, but they certainly didn’t expect this.

The stringlike worm was five-sixteenths of an inch long, was alive, and wiggled.

“It stunned everyone in that operating theater,” Sanjaya Senanayake, MBBS, an associate professor of infectious disease at Australian National University, Canberra, and senior author of the case report, said in an interview. “When you operate on a brain, you don’t expect to find anything alive.”

The parasitic worm was about half the width of a dime. Helminths like it can usually be seen with the naked eye but are often found in the intestines after being transmitted by soil and infecting the gastrointestinal tract. But this one made it into a woman’s brain in a first-of-its-kind case reported in the journal Emerging Infectious Diseases).

“We weren’t suspecting a worm at all,” Dr. Senanayake said. “There was something abnormal there. Was it going to be granulomatous lesion? Was it going to be cancer? Who knows, but it needed to be biopsied, and a worm was the last thing at the back of anyone’s mind,” he said.
 

A year of inexplicable symptoms

The 64-year-old woman was diagnosed with pneumonia and had a high white blood cell count, low hemoglobin, high platelets, and a very high C-reactive protein of 102 mg/L.

She hadn’t fully recovered from her illness when the abdominal pain and diarrhea started. And then she had a dry cough and night sweats.

After 3 weeks of discomfort, she was admitted to the hospital. She had a history of diabetes, hypothyroidism, and depression, and doctors began looking for answers to her acute illness.

They tested for autoimmune diseases and parasitic infections and prescribed prednisolone to help ease symptoms.

But 3 weeks later, her fever and cough persisted, and she was readmitted to the hospital. Doctors ordered more tests, and her eosinophils were still high, plus there were lesions on her liver, spleen, and lungs.

But tests were negative for bacterial, fungal, and mycobacterial cultures. Her stools showed no evidence of parasites.

She was prescribed mycophenolate and then ivermectin in case her tests for roundworm were a false negative. Doctors suspected Strongyloides, but lesions remained on her spleen even as the liver and lung lesions improved.

Reducing the prednisolone dose affected respiratory symptoms, so by January 2022, a year after initial symptoms began, the medical team added the monoclonal antibody mepolizumab. But her symptoms worsened, and she developed forgetfulness and more depression.

After a brain MRI revealed a right frontal lobe lesion, the team recommended an open biopsy and discovered the worm. The specimen was Ophidascaris robertsi, the intestinal roundworm typically of the carpet python. Never before seen in a human, the only other animals in its life cycle are small marsupials or mammals consumed by pythons.
 

A snake’s bug

Although this is the first case of an Ophidascaris infection in a human, other cases could occur, warn the doctors in their case report.

The best guess for how the patient contracted the infection was by inadvertently consuming larval eggs on wild vegetation that she collected near her home to eat. She lived near a lake known to be home to carpet pythons, so the eggs could have been on the plants she collected or on her hands or kitchen equipment.

“If you’re foraging or using native grasses or plants in recipes, it would be a good idea to cook those instead of having a salad,” Dr. Senanayake said. “That would make the chance of getting something really rare even less likely.”

It’s unclear how or why the worm, which usually stays in the gut, made its way into the patient’s brain, but her long course of immunosuppressing drugs may have played a role, the team points out. “If the normal immune barriers are reduced, then it’s easier for the parasite to move around between organ systems,” Dr. Senanayake said.

Doctors also wondered if she may have been getting re-infected when she went home between hospital admissions. After removing the worm, she received 4 weeks of treatment with albendazole to eliminate any other possible larvae in other organs, especially since Ophidascaris larvae have been known to survive for long periods – more than 4 years in laboratory rats. “The hope is that she’s been cured of this parasitic infection,” Dr. Senanayake said.

As people around the world contend with the global COVID pandemic, they might not realize that new infections are arising around the world every year, he explained.
 

Novel parasitic infections

“The reality is that 30 new infections appeared in the last 30 years, and three-quarters of them are zoonotic, animal infections spilling over into the human world,” Dr. Senanayake said.

Though some of that number is the result of improved surveillance and diagnostics, a real increase has been occurring as human settlements continue expanding.

“This is just a reflection of how burgeoning human populations are encroaching upon animal habitats, and we’re getting more interactions between humans and wild animals, domestic animals and wild animals, and humans and natural flora, which is increasing the risk of this type of infection being recognized,” he explained.

The Ophidascaris worm found in this instance is in other snake species in different continents around the world, too. “Awareness of this case will hopefully lead to the diagnosis and treatment of other cases,” Dr. Senanayake added.

Though it’s certainly surprising to find this particular parasite in a human, finding a zoonotic organism in a person isn’t that strange, according to Janet Foley, DVM, PhD, a professor of veterinary medicine at the University of California, Davis. This is especially true if the usual host is closely related to humans, like primates, or spends a lot of time around them, like rats.

“There are still a lot of parasites and diseases out there in wildlife that haven’t been discovered, and we don’t know the risk,” said Dr. Foley. “But still, the risk would have to be low, generally, or we would see more human cases.”

In the United States, the roundworm common in raccoon feces is Baylisascaris procyonis and can be dangerous for people. “There have been deaths in people exposed to these worms, which do seem to prefer to travel to a human brain,” Dr. Foley said.

A 2016 Centers for Disease Control and Prevention report described seven U.S. cases identified between May 2013 and December 2015, including six that caused central nervous system disease. Another case report in 2018 involved a toddler who had eaten dirt and animal feces in his backyard.

And this past June, an Emerging Infectious Diseases case report described a B. procyonis infection in a 7-year-old with autism spectrum disorder and a history of pica. He had put material in his mouth from the ground near a tree where epidemiologists later found raccoon feces.

Still, Dr. Senanayake cautions against people jumping to conclusions about parasitic infections when they experience symptoms that aren’t otherwise immediately explainable.

The typical person who develops forgetfulness, depression, and a fever probably doesn’t have a worm in their brain or need an immediate MRI, he pointed out. “There may be other cases out there, but common things happen commonly, and this is likely to be rare,” Dr. Senanayake said.

This case demonstrates the challenge in picking a course of treatment when the differential diagnoses for hypereosinophilic syndromes is so broad.
 

Tricky hypereosinophilic syndromes

One of those differentials for the syndromes is parasitic infections, for which treatment would be antiparasitic agents, but another differential is an autoimmune condition that would call for immunosuppression.

“Obviously, as with this case, you don’t want to give someone immunosuppressive treatment if they’ve got a parasite, so you want to look really hard for a parasite before you start them on immunosuppressive treatment for an immunological condition,” Dr. Senanayake said.

But all the blood tests for different antibodies came back negative for parasites, “and this parasite was simply difficult to find until they pulled it from her brain,” he said.

Infectious disease physicians are always looking for the unusual and exotic, Dr. Senanayake explained. But it’s important to exclude the common, easy things first, he added. It’s after exhausting all the likely culprits that “you have to start really thinking laterally and putting resources into unusual tests.”

A version of this article first appeared on Medscape.com.

Several signs are pointing to an impending surge in the number of human cases of West Nile virus in several regions of the United States.

West Nile virus is spread by infected mosquitoes and currently there is no cure or virus-specific treatment. In rare cases, it can be deadly. It can infect humans, birds, horses, and other mammals.

West Nile Virus is the leading cause of mosquito-borne disease in the continental United States. As of Aug. 8, 126 human cases had been identified across 22 states, according to the Centers for Disease Control and Prevention.

“Particularly here in California, it’s peak risk right now,” said Vicki Kramer, PhD, chief of vector-borne diseases in the California Department of Public Health. She said scientists there are seeing higher mosquito and infected mosquito numbers.
 

“Peak risk right now”

Dead birds are tested for the virus and by Aug. 4, 181 of the 913 birds tested in California have been positive, three times the total testing positive by this time in 2022.

“Last year at this time, we had 60 positive dead birds out of 817 tested,” Dr. Kramer said.

Severe flooding and high heat can contribute to the rise in mosquito populations and many parts of the country have seen plenty of both.

One of the ways scientists track infected mosquito patterns in California is by using flocks of strategically placed sentinel chickens.

“Chickens are a mosquito magnet,” Dr. Kramer said.

Chickens don’t get sick with the virus, but they do build antibodies to it. Surveillance teams check their blood every other week to track the virus.

Daniel Pastula, MD, MHS, chief of neuroinfectious diseases and global neurology at the University of Colorado School of Medicine and the Colorado School of Public Health, said the state is watching troubling signs as well.

“The concern this year,” Dr. Pastula said, “particularly along the Front Range in Colorado, is we’ve found many more mosquitoes [that are] positive for West Nile earlier in the season compared with other years.

“We’re bracing for higher-than-baseline human cases,” he said.

Asked about this year’s first human case, reported in Toronto, a region with a long winter and low incidence of the virus, he said that provides a further example that people need to be prepared even in climates not known to be mosquito-dense.

He added, however, that climate is only one factor in the severity of the season. Others include birds’ immunity and migratory patterns.

Dr. Pastula said that fluctuations in temperature and rainfall are rising with climate change and are disrupting normal baseline levels of West Nile.

“That shows we need to be prepared for West Nile virus and other mosquito-borne diseases in any place in North America or really the world. We recently saw malaria cases in the southern United States. It just shows you how dangerous mosquitoes can be.”
 

Avoid mosquito bites

Dr. Pastula and Dr. Kramer list the precautions people can take to protect themselves from West Nile virus:

• Limit outdoor exposure particularly at dusk and dawn.
• Wear protective clothing.
• Use .
• Repair window screens so mosquitoes cannot fly through.
• Dump and drain standing water on your property and maintain swimming pools.

Dr. Pastula noted that summer is the time human cases start to mount – typically from July and August to the first hard freeze.

“We have been warning people here up and down the Front Range of Colorado to take prevention very seriously,” Dr. Pastula said.

He pointed out that 80% who are infected with West Nile will have no symptoms.

About 20% will have flu-like illness – high fever, body and joint aches, rash, diarrhea, or headaches. Symptoms may last for weeks. About 1% of the time, he said, people can get neuroinvasive West Nile.

Dr. Pastula explained that the virus can infect the covering of the brain and spinal cord causing meningitis with very high fever, severe headaches, stiff neck, and sensitivity to light.

So far this year, there have been 89 neuroinvasive cases reported nationally, according to the CDC.

With West Nile encephalitis, the virus “can infect the brain itself causing altered mental status, movement disorders, or weakness,” Dr. Pastula said.

Sometimes it can infect the gray matter of the spinal cord causing a West Nile virus poliomyelitis, which brings polio-like symptoms.

“The West Nile encephalitis and poliomyelitis can cause permanent deficits or even death,” he said. “It’s uncommon but it’s not trivial.”

Several vaccine candidates are in development, Dr. Pastula said, but none has reached clinical trials. Part of the reason for that, he said, is that scientists must be able to predict the timing of an outbreak.

“We’re not really great at predicting outbreaks,” he said.

Although the risk for neuroinvasive disease is small, it can be higher in certain groups, he said – those who are over age 60 years or are immunocompromised; those who have diabetes, cancer, or kidney disease; or those who have undergone organ transplants.

Those infected should see a health care professional and may be able to get relief with the usual medications for flu-like illness.

Some with severe infection may need to go to the hospital, Dr. Pastula said.
 

A version of this article first appeared on Medscape.com.

Several signs are pointing to an impending surge in the number of human cases of West Nile virus in several regions of the United States.

West Nile virus is spread by infected mosquitoes and currently there is no cure or virus-specific treatment. In rare cases, it can be deadly. It can infect humans, birds, horses, and other mammals.

West Nile Virus is the leading cause of mosquito-borne disease in the continental United States. As of Aug. 8, 126 human cases had been identified across 22 states, according to the Centers for Disease Control and Prevention.

“Particularly here in California, it’s peak risk right now,” said Vicki Kramer, PhD, chief of vector-borne diseases in the California Department of Public Health. She said scientists there are seeing higher mosquito and infected mosquito numbers.
 

“Peak risk right now”

Dead birds are tested for the virus and by Aug. 4, 181 of the 913 birds tested in California have been positive, three times the total testing positive by this time in 2022.

“Last year at this time, we had 60 positive dead birds out of 817 tested,” Dr. Kramer said.

Severe flooding and high heat can contribute to the rise in mosquito populations and many parts of the country have seen plenty of both.

One of the ways scientists track infected mosquito patterns in California is by using flocks of strategically placed sentinel chickens.

“Chickens are a mosquito magnet,” Dr. Kramer said.

Chickens don’t get sick with the virus, but they do build antibodies to it. Surveillance teams check their blood every other week to track the virus.

Daniel Pastula, MD, MHS, chief of neuroinfectious diseases and global neurology at the University of Colorado School of Medicine and the Colorado School of Public Health, said the state is watching troubling signs as well.

“The concern this year,” Dr. Pastula said, “particularly along the Front Range in Colorado, is we’ve found many more mosquitoes [that are] positive for West Nile earlier in the season compared with other years.

“We’re bracing for higher-than-baseline human cases,” he said.

Asked about this year’s first human case, reported in Toronto, a region with a long winter and low incidence of the virus, he said that provides a further example that people need to be prepared even in climates not known to be mosquito-dense.

He added, however, that climate is only one factor in the severity of the season. Others include birds’ immunity and migratory patterns.

Dr. Pastula said that fluctuations in temperature and rainfall are rising with climate change and are disrupting normal baseline levels of West Nile.

“That shows we need to be prepared for West Nile virus and other mosquito-borne diseases in any place in North America or really the world. We recently saw malaria cases in the southern United States. It just shows you how dangerous mosquitoes can be.”
 

Avoid mosquito bites

Dr. Pastula and Dr. Kramer list the precautions people can take to protect themselves from West Nile virus:

• Limit outdoor exposure particularly at dusk and dawn.
• Wear protective clothing.
• Use .
• Repair window screens so mosquitoes cannot fly through.
• Dump and drain standing water on your property and maintain swimming pools.

Dr. Pastula noted that summer is the time human cases start to mount – typically from July and August to the first hard freeze.

“We have been warning people here up and down the Front Range of Colorado to take prevention very seriously,” Dr. Pastula said.

He pointed out that 80% who are infected with West Nile will have no symptoms.

About 20% will have flu-like illness – high fever, body and joint aches, rash, diarrhea, or headaches. Symptoms may last for weeks. About 1% of the time, he said, people can get neuroinvasive West Nile.

Dr. Pastula explained that the virus can infect the covering of the brain and spinal cord causing meningitis with very high fever, severe headaches, stiff neck, and sensitivity to light.

So far this year, there have been 89 neuroinvasive cases reported nationally, according to the CDC.

With West Nile encephalitis, the virus “can infect the brain itself causing altered mental status, movement disorders, or weakness,” Dr. Pastula said.

Sometimes it can infect the gray matter of the spinal cord causing a West Nile virus poliomyelitis, which brings polio-like symptoms.

“The West Nile encephalitis and poliomyelitis can cause permanent deficits or even death,” he said. “It’s uncommon but it’s not trivial.”

Several vaccine candidates are in development, Dr. Pastula said, but none has reached clinical trials. Part of the reason for that, he said, is that scientists must be able to predict the timing of an outbreak.

“We’re not really great at predicting outbreaks,” he said.

Although the risk for neuroinvasive disease is small, it can be higher in certain groups, he said – those who are over age 60 years or are immunocompromised; those who have diabetes, cancer, or kidney disease; or those who have undergone organ transplants.

Those infected should see a health care professional and may be able to get relief with the usual medications for flu-like illness.

Some with severe infection may need to go to the hospital, Dr. Pastula said.
 

A version of this article first appeared on Medscape.com.

Several signs are pointing to an impending surge in the number of human cases of West Nile virus in several regions of the United States.

West Nile virus is spread by infected mosquitoes and currently there is no cure or virus-specific treatment. In rare cases, it can be deadly. It can infect humans, birds, horses, and other mammals.

West Nile Virus is the leading cause of mosquito-borne disease in the continental United States. As of Aug. 8, 126 human cases had been identified across 22 states, according to the Centers for Disease Control and Prevention.

“Particularly here in California, it’s peak risk right now,” said Vicki Kramer, PhD, chief of vector-borne diseases in the California Department of Public Health. She said scientists there are seeing higher mosquito and infected mosquito numbers.
 

“Peak risk right now”

Dead birds are tested for the virus and by Aug. 4, 181 of the 913 birds tested in California have been positive, three times the total testing positive by this time in 2022.

“Last year at this time, we had 60 positive dead birds out of 817 tested,” Dr. Kramer said.

Severe flooding and high heat can contribute to the rise in mosquito populations and many parts of the country have seen plenty of both.

One of the ways scientists track infected mosquito patterns in California is by using flocks of strategically placed sentinel chickens.

“Chickens are a mosquito magnet,” Dr. Kramer said.

Chickens don’t get sick with the virus, but they do build antibodies to it. Surveillance teams check their blood every other week to track the virus.

Daniel Pastula, MD, MHS, chief of neuroinfectious diseases and global neurology at the University of Colorado School of Medicine and the Colorado School of Public Health, said the state is watching troubling signs as well.

“The concern this year,” Dr. Pastula said, “particularly along the Front Range in Colorado, is we’ve found many more mosquitoes [that are] positive for West Nile earlier in the season compared with other years.

“We’re bracing for higher-than-baseline human cases,” he said.

Asked about this year’s first human case, reported in Toronto, a region with a long winter and low incidence of the virus, he said that provides a further example that people need to be prepared even in climates not known to be mosquito-dense.

He added, however, that climate is only one factor in the severity of the season. Others include birds’ immunity and migratory patterns.

Dr. Pastula said that fluctuations in temperature and rainfall are rising with climate change and are disrupting normal baseline levels of West Nile.

“That shows we need to be prepared for West Nile virus and other mosquito-borne diseases in any place in North America or really the world. We recently saw malaria cases in the southern United States. It just shows you how dangerous mosquitoes can be.”
 

Avoid mosquito bites

Dr. Pastula and Dr. Kramer list the precautions people can take to protect themselves from West Nile virus:

• Limit outdoor exposure particularly at dusk and dawn.
• Wear protective clothing.
• Use .
• Repair window screens so mosquitoes cannot fly through.
• Dump and drain standing water on your property and maintain swimming pools.

Dr. Pastula noted that summer is the time human cases start to mount – typically from July and August to the first hard freeze.

“We have been warning people here up and down the Front Range of Colorado to take prevention very seriously,” Dr. Pastula said.

He pointed out that 80% who are infected with West Nile will have no symptoms.

About 20% will have flu-like illness – high fever, body and joint aches, rash, diarrhea, or headaches. Symptoms may last for weeks. About 1% of the time, he said, people can get neuroinvasive West Nile.

Dr. Pastula explained that the virus can infect the covering of the brain and spinal cord causing meningitis with very high fever, severe headaches, stiff neck, and sensitivity to light.

So far this year, there have been 89 neuroinvasive cases reported nationally, according to the CDC.

With West Nile encephalitis, the virus “can infect the brain itself causing altered mental status, movement disorders, or weakness,” Dr. Pastula said.

Sometimes it can infect the gray matter of the spinal cord causing a West Nile virus poliomyelitis, which brings polio-like symptoms.

“The West Nile encephalitis and poliomyelitis can cause permanent deficits or even death,” he said. “It’s uncommon but it’s not trivial.”

Several vaccine candidates are in development, Dr. Pastula said, but none has reached clinical trials. Part of the reason for that, he said, is that scientists must be able to predict the timing of an outbreak.

“We’re not really great at predicting outbreaks,” he said.

Although the risk for neuroinvasive disease is small, it can be higher in certain groups, he said – those who are over age 60 years or are immunocompromised; those who have diabetes, cancer, or kidney disease; or those who have undergone organ transplants.

Those infected should see a health care professional and may be able to get relief with the usual medications for flu-like illness.

Some with severe infection may need to go to the hospital, Dr. Pastula said.
 

A version of this article first appeared on Medscape.com.

Experience with long COVID has shone a spotlight on persistent Lyme disease and other often debilitating chronic illnesses that follow known or suspected infections – and on the urgent need for a common and well-funded research agenda, education of physicians, growth of multidisciplinary clinics, and financially supported clinical care.

“We critically need to understand the epidemiology and pathogenesis of chronic symptoms, and identify more effective ways to manage, treat, and potentially cure these illnesses,” Lyle Petersen, MD, MPH, director of the division of vector-borne diseases at the Centers for Disease Control and Prevention, said at the start of a 2-day National Academies of Science, Engineering, and Medicine (NASEM) workshop, “Toward a Common Research Agenda in Infection-Associated Chronic Illnesses.”

Thinking about infection-associated chronic illnesses as an entity – one predicated on commonalities in chronic symptoms and in leading hypotheses for causes – represents a paradigm shift that researchers and patient advocates said can avoid research redundancies and is essential to address what the NASEM calls an overlooked, growing public health problem.

An estimated 2 million people in the United States are living with what’s called posttreatment Lyme disease (PTLD) – a subset of patients with persistent or chronic Lyme disease – and an estimated 1.7-3.3 million people in the United States have diagnoses of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). More than 700,000 people are living with multiple sclerosis. And as of January 2023, 11% of people in the United States reported having long COVID symptoms; the incidence of long COVID is currently estimated at 10%-30% of nonhospitalized cases of COVID-19.

These illnesses “have come under one umbrella,” said Avindra Nath, MD, clinical director of the National Institute of Neurologic Disorders and Stroke (NINDS), Bethesda, Md.

Dr. Nath

Persistent infection, viral reactivation

RNA viral infections can lead to persistent inflammation and dysregulated immunity, with or without viral persistence over time, Timothy J. Henrich, MD, MMSc, associate professor of medicine at the University of California, San Francisco, said in a keynote address.

Research on Ebola survivors has documented long-lasting inflammation and severe immune dysfunction 2 years after infection, for instance. And it’s well known that HIV-1 leads to aberrant immune responses, inflammation, and organ damage despite antiretroviral therapy, said Dr. Henrich, who leads a laboratory/research group that studies approaches to HIV-1 cure and PET-based imaging approaches to characterize viral reservoirs and immune sequelae.

Viral persistence, which can be difficult to measure, has also been documented in Ebola survivors. And in patients living with HIV-1, HIV-1 RNA and protein expression have been shown to persist, again despite antiretroviral therapy. The UCSF Long-Term Immunological Impact of Novel Coronavirus (LIINC) study, for which Dr. Henrich is the principal investigator, found spike RNA in colorectal tissue more than 22 months post COVID, and other research documented viral protein in gut tissue for up to 6 months, he said.

“I think we’re appreciating now, in at least the scientific and treatment community, that there’s a potential for ‘acute’ infections to exhibit some degree of persistence leading to clinical morbidity,” said Dr. Henrich, one of several speakers to describe reports of pathogen persistence. Regarding long COVID, its “etiology is likely heterogeneous,” he said, but persistence of SARS-CoV-2 “may lay behind” other described mechanisms, from clotting/microvascular dysfunction to inflammation and tissue damage to immune dysregulation.

Reactivation of existing latent viral infections in the setting of new acute microbial illness may also play an etiologic role in chronic illnesses, Dr. Henrich said. Epstein-Barr virus (EBV) reactivation has been shown in some studies, including their UCSF COVID-19 cohort, to be associated with long COVID.

“Physicians have been trained to be skeptical about the role [of latent viral infections],” Michael Peluso, MD, an infectious disease physician and assistant professor at UCSF, said during a talk on viral reactivation. This skepticism needs to be “reexamined and overcome,” he said.

Herpesviruses have frequently been associated with ME/CFS, he noted. And evidence of a strong association between EBV and multiple sclerosis came recently from a prospective study of 10 million military recruits that found a 32-fold increased risk of MS after EBV infection but no increase after infection with other viruses, Dr. Peluso and Dr. Henrich both noted.
 

Research needs, treatment trials

Research needs are vast: The need to learn more about the mechanisms of pathogen persistence and immune evasion, for instance, and the need for more biomarker studies, more imaging studies and tissue analyses, more study of microbiome composition and activity, and continued development and application of metagenomic next-generation sequencing.

Workshop participants also spoke of the need to better understand the molecular mimicry that can occur between pathogen-produced proteins and self-antigens, for instance, and the effects of inflammation and infection-related immune changes on neuronal and microglial function in the brain.

“We should perform similar forms of analysis [across] patients with different infection-associated chronic conditions,” said Amy Proal, PhD, president of the PolyBio Research Foundation, which funds research on infection-associated chronic infections. And within individual conditions and well-characterized study groups “we should perform many different forms of analysis … so we can define endotypes and get more solid biomarkers so that industry [will have more confidence] to run clinical trials.”

In the meantime, patients need fast-moving treatment trials for long COVID, long Lyme, and other infection-associated chronic illnesses, speakers emphasized. “We all agree that treatment trials are overdue,” said the NINDS’ Dr. Nath. “We can’t afford to wait for another decade until we understand all the mechanisms, but rather we can do clinical trials based on what we understand now and study the pathophysiology in the context of the clinical trials.”

Just as was done with HIV, said Steven G. Deeks, MD, professor of medicine at UCSF, researchers must “practice experimental medicine” and select pathways and mechanisms of interest, interrupt those pathways in a controlled manner, and assess impact. “Much of this can be done by repurposing existing drugs,” he said, like antivirals for persistent viral infection, EBV-directed therapies for EBV reactivation, anti-inflammatory drugs for inflammation, B–cell-directed therapies for autoantibodies, and antiplatelet drugs for microvascular disease.

When done correctly, he said, such “probe” studies can deepen mechanistic understandings, lead to biomarkers, and provide proof-of-concept that “will encourage massive investment in developing new therapies” for long COVID and other infection-associated chronic illnesses.

Trials of treatments for long COVID “are starting, so I’m optimistic,” said Dr. Deeks, an expert on HIV pathogenesis and treatment and a principal investigator of the Researching COVID to Enhance Recovery (RECOVER) study. Among the trials: A study of intravenous immunoglobulin (IVIG) for neurologic long COVID; a study of an anti-SARS-CoV-2 monoclonal antibody that can deplete tissue/cellular reservoirs of viral particles (replicating or not); and a study evaluating baricitinib (Olumiant), a Janus kinase inhibitor, for neurocognitive impairment and cardiopulmonary symptoms of long COVID.

Alessio Fasano, MD, professor of pediatrics at Harvard Medical School and professor of nutrition at the Harvard T.H. Chan School of Public Health, Boston, described at the workshop how he began investigating the use of larazotide acetate – an inhibitor of the protein zonulin, which increases intestinal permeability – in children with COVID-19 Multisystem Inflammatory Syndrome (MIS-C) after learning that SARS-CoV-2 viral particles persist in the gastrointestinal tract, causing dysbiosis and zonulin upregulation.

In an ongoing phase 2, double-blind, placebo-controlled trial, the agent thus far has expedited the resolution of gastrointestinal symptoms and clearance of spike protein from the circulation, he said. A phase 2 trial of the agent for pediatric patients with long COVID and SARS-CoV-2 antigenemia is underway. “What if we were to stop [chains of events] by stopping the passage of elements from the virus into circulation?’ he said.

In the realm of Lyme disease, a recently launched Clinical Trials Network for Lyme and Other Tick-Borne Diseases has awarded pilot study grants to evaluate treatments aimed at a variety of possible disease mechanisms that, notably, are similar to those of other chronic illnesses: persistence of infection or remnants of infection, immune dysregulation and autoimmune reactions, neural dysfunction, and gut microbiome changes. (Microclots and mitochondrial dysfunction have not been as well studied in Lyme.)

Current and upcoming studies include evaluations of transcutaneous auricular vagus nerve stimulation for those with persistent Lyme fatigue, transcranial direct current stimulation with cognitive retraining for Lyme brain fog, and tetracycline for PTLD, said Brian Fallon, MD, MPH, professor of clinical psychiatry at Columbia University, New York, who directs the Lyme & Tick-Borne Diseases Research Center and the coordinating center of the new network.

Columbia University Irving Medical Center

Calls for a new NIH center and patient involvement

Patients and patient advocacy organizations have played a vital role in research thus far: They’ve documented post-COVID symptoms that academic researchers said they would not otherwise have known of. Leaders of the Patient-Led Research Collaborative have coauthored published reviews with leading long COVID experts. And patients with tick-borne illnesses have enrolled in the MyLymeData patient registry run by LymeDisease.org, which has documented patient-experienced efficacy of alternative treatments and described antibiotic responders and nonresponders.

At the workshop, they shared findings alongside academic experts, and researchers called for their continued involvement. “Patient engagement at every step of the research process is critical,” Dr. Nath said.

“We need to ensure that research is reflective of lived experiences … and [that we’re] accelerating clinical trials of therapeutics that are of priority to the patient community,” said Lisa McCorkell, cofounder of the long COVID-focused Patient-Led Research Collaborative.

Ms. McCorkell also called for the creation of an office for infection-associated chronic illnesses in the NIH director’s office. Others voiced their support. “I think it’s a great idea to have an NIH center for infection-associated chronic illnesses,” said Dr. Fallon. “I think it would have a profound impact.”

The other great need, of course, is funding. “We have ideas, we have drugs that can be repurposed, we have a highly informed and engaged community that will enroll in and be retained in studies, and we have outcomes we can measure,” Dr. Deeks said. “What we’re missing is industry engagement and funding. We need massive engagement from the NIH.”
 

Real-world treatment needs

In the meantime, patients are seeking treatment, and “clinicians need to have uncertainty tolerance” and try multiple treatments simultaneously, said David Putrino, PT, PhD, director of rehabilitation innovation for the Mount Sinai Health System and professor of rehabilitation and human performance at the Icahn School of Medicine at Mount Sinai, New York. He oversees a multidisciplinary hybrid clinical care research center that has seen over 1,500 patients with long COVID and is beginning to see patients with other infection-associated chronic illnesses.

Claudia Paul

It’s a model that should be replicated to help fill the “enormous unmet clinical need” of patients with infection-associated chronic illness, said Peter Rowe, MD, professor of pediatrics at the Johns Hopkins School of Medicine and an expert on ME/CFS. And “as we request [more research funding], we will also need [financial] support for clinical care,” he emphasized, to provide equitable access for patients and to attract treating physicians.

Moreover, said Linda Geng, MD, PhD, the culture of stigma needs to change. Right now, patients with long COVID often feel dismissed not only by friends, families, and coworkers, but by clinicians who find it find it hard “to grasp that this is real and a biological condition.”

And it’s not just conditions such as long COVID that are stigmatized, but treatments as well, she said. For instance, some clinicians view low-dose naltrexone, a treatment increasingly being used for inflammation, with suspicion because it is used for opioid use disorder and alcohol use disorder – or because the “low-dose” label summons mistrust of homeopathy. “Even with therapies, there are preconceived notions and biases,” said Dr. Geng, cofounder and codirector of the Stanford (Calif.) Long COVID program.

“What almost killed me,” said Meghan O’Rourke, who has ongoing effects from long-undiagnosed tick-borne illness, “was the invisibility of the illness.” Ms. O’Rourke teaches at Yale University and is the author of “The Invisible Kingdom: Reimagining Chronic Illness.”

Teaching young physicians about these illnesses would help, she and others said. During a question and answer session, Dr. Putrino shared that the Icahn School of Medicine has recently committed to “create a complex chronic illness medical curriculum” that will impact medical education from the first year of medical school through residencies. Dr. Putrino said his team is also working on materials to help other clinics develop care models similar to those at his Mount Sinai clinic.

The NASEM workshop did not collect or require disclosures of its participants.

Experience with long COVID has shone a spotlight on persistent Lyme disease and other often debilitating chronic illnesses that follow known or suspected infections – and on the urgent need for a common and well-funded research agenda, education of physicians, growth of multidisciplinary clinics, and financially supported clinical care.

“We critically need to understand the epidemiology and pathogenesis of chronic symptoms, and identify more effective ways to manage, treat, and potentially cure these illnesses,” Lyle Petersen, MD, MPH, director of the division of vector-borne diseases at the Centers for Disease Control and Prevention, said at the start of a 2-day National Academies of Science, Engineering, and Medicine (NASEM) workshop, “Toward a Common Research Agenda in Infection-Associated Chronic Illnesses.”

Thinking about infection-associated chronic illnesses as an entity – one predicated on commonalities in chronic symptoms and in leading hypotheses for causes – represents a paradigm shift that researchers and patient advocates said can avoid research redundancies and is essential to address what the NASEM calls an overlooked, growing public health problem.

An estimated 2 million people in the United States are living with what’s called posttreatment Lyme disease (PTLD) – a subset of patients with persistent or chronic Lyme disease – and an estimated 1.7-3.3 million people in the United States have diagnoses of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). More than 700,000 people are living with multiple sclerosis. And as of January 2023, 11% of people in the United States reported having long COVID symptoms; the incidence of long COVID is currently estimated at 10%-30% of nonhospitalized cases of COVID-19.

These illnesses “have come under one umbrella,” said Avindra Nath, MD, clinical director of the National Institute of Neurologic Disorders and Stroke (NINDS), Bethesda, Md.

Dr. Nath

Persistent infection, viral reactivation

RNA viral infections can lead to persistent inflammation and dysregulated immunity, with or without viral persistence over time, Timothy J. Henrich, MD, MMSc, associate professor of medicine at the University of California, San Francisco, said in a keynote address.

Research on Ebola survivors has documented long-lasting inflammation and severe immune dysfunction 2 years after infection, for instance. And it’s well known that HIV-1 leads to aberrant immune responses, inflammation, and organ damage despite antiretroviral therapy, said Dr. Henrich, who leads a laboratory/research group that studies approaches to HIV-1 cure and PET-based imaging approaches to characterize viral reservoirs and immune sequelae.

Viral persistence, which can be difficult to measure, has also been documented in Ebola survivors. And in patients living with HIV-1, HIV-1 RNA and protein expression have been shown to persist, again despite antiretroviral therapy. The UCSF Long-Term Immunological Impact of Novel Coronavirus (LIINC) study, for which Dr. Henrich is the principal investigator, found spike RNA in colorectal tissue more than 22 months post COVID, and other research documented viral protein in gut tissue for up to 6 months, he said.

“I think we’re appreciating now, in at least the scientific and treatment community, that there’s a potential for ‘acute’ infections to exhibit some degree of persistence leading to clinical morbidity,” said Dr. Henrich, one of several speakers to describe reports of pathogen persistence. Regarding long COVID, its “etiology is likely heterogeneous,” he said, but persistence of SARS-CoV-2 “may lay behind” other described mechanisms, from clotting/microvascular dysfunction to inflammation and tissue damage to immune dysregulation.

Reactivation of existing latent viral infections in the setting of new acute microbial illness may also play an etiologic role in chronic illnesses, Dr. Henrich said. Epstein-Barr virus (EBV) reactivation has been shown in some studies, including their UCSF COVID-19 cohort, to be associated with long COVID.

“Physicians have been trained to be skeptical about the role [of latent viral infections],” Michael Peluso, MD, an infectious disease physician and assistant professor at UCSF, said during a talk on viral reactivation. This skepticism needs to be “reexamined and overcome,” he said.

Herpesviruses have frequently been associated with ME/CFS, he noted. And evidence of a strong association between EBV and multiple sclerosis came recently from a prospective study of 10 million military recruits that found a 32-fold increased risk of MS after EBV infection but no increase after infection with other viruses, Dr. Peluso and Dr. Henrich both noted.
 

Research needs, treatment trials

Research needs are vast: The need to learn more about the mechanisms of pathogen persistence and immune evasion, for instance, and the need for more biomarker studies, more imaging studies and tissue analyses, more study of microbiome composition and activity, and continued development and application of metagenomic next-generation sequencing.

Workshop participants also spoke of the need to better understand the molecular mimicry that can occur between pathogen-produced proteins and self-antigens, for instance, and the effects of inflammation and infection-related immune changes on neuronal and microglial function in the brain.

“We should perform similar forms of analysis [across] patients with different infection-associated chronic conditions,” said Amy Proal, PhD, president of the PolyBio Research Foundation, which funds research on infection-associated chronic infections. And within individual conditions and well-characterized study groups “we should perform many different forms of analysis … so we can define endotypes and get more solid biomarkers so that industry [will have more confidence] to run clinical trials.”

In the meantime, patients need fast-moving treatment trials for long COVID, long Lyme, and other infection-associated chronic illnesses, speakers emphasized. “We all agree that treatment trials are overdue,” said the NINDS’ Dr. Nath. “We can’t afford to wait for another decade until we understand all the mechanisms, but rather we can do clinical trials based on what we understand now and study the pathophysiology in the context of the clinical trials.”

Just as was done with HIV, said Steven G. Deeks, MD, professor of medicine at UCSF, researchers must “practice experimental medicine” and select pathways and mechanisms of interest, interrupt those pathways in a controlled manner, and assess impact. “Much of this can be done by repurposing existing drugs,” he said, like antivirals for persistent viral infection, EBV-directed therapies for EBV reactivation, anti-inflammatory drugs for inflammation, B–cell-directed therapies for autoantibodies, and antiplatelet drugs for microvascular disease.

When done correctly, he said, such “probe” studies can deepen mechanistic understandings, lead to biomarkers, and provide proof-of-concept that “will encourage massive investment in developing new therapies” for long COVID and other infection-associated chronic illnesses.

Trials of treatments for long COVID “are starting, so I’m optimistic,” said Dr. Deeks, an expert on HIV pathogenesis and treatment and a principal investigator of the Researching COVID to Enhance Recovery (RECOVER) study. Among the trials: A study of intravenous immunoglobulin (IVIG) for neurologic long COVID; a study of an anti-SARS-CoV-2 monoclonal antibody that can deplete tissue/cellular reservoirs of viral particles (replicating or not); and a study evaluating baricitinib (Olumiant), a Janus kinase inhibitor, for neurocognitive impairment and cardiopulmonary symptoms of long COVID.

Alessio Fasano, MD, professor of pediatrics at Harvard Medical School and professor of nutrition at the Harvard T.H. Chan School of Public Health, Boston, described at the workshop how he began investigating the use of larazotide acetate – an inhibitor of the protein zonulin, which increases intestinal permeability – in children with COVID-19 Multisystem Inflammatory Syndrome (MIS-C) after learning that SARS-CoV-2 viral particles persist in the gastrointestinal tract, causing dysbiosis and zonulin upregulation.

In an ongoing phase 2, double-blind, placebo-controlled trial, the agent thus far has expedited the resolution of gastrointestinal symptoms and clearance of spike protein from the circulation, he said. A phase 2 trial of the agent for pediatric patients with long COVID and SARS-CoV-2 antigenemia is underway. “What if we were to stop [chains of events] by stopping the passage of elements from the virus into circulation?’ he said.

In the realm of Lyme disease, a recently launched Clinical Trials Network for Lyme and Other Tick-Borne Diseases has awarded pilot study grants to evaluate treatments aimed at a variety of possible disease mechanisms that, notably, are similar to those of other chronic illnesses: persistence of infection or remnants of infection, immune dysregulation and autoimmune reactions, neural dysfunction, and gut microbiome changes. (Microclots and mitochondrial dysfunction have not been as well studied in Lyme.)

Current and upcoming studies include evaluations of transcutaneous auricular vagus nerve stimulation for those with persistent Lyme fatigue, transcranial direct current stimulation with cognitive retraining for Lyme brain fog, and tetracycline for PTLD, said Brian Fallon, MD, MPH, professor of clinical psychiatry at Columbia University, New York, who directs the Lyme & Tick-Borne Diseases Research Center and the coordinating center of the new network.

Columbia University Irving Medical Center

Calls for a new NIH center and patient involvement

Patients and patient advocacy organizations have played a vital role in research thus far: They’ve documented post-COVID symptoms that academic researchers said they would not otherwise have known of. Leaders of the Patient-Led Research Collaborative have coauthored published reviews with leading long COVID experts. And patients with tick-borne illnesses have enrolled in the MyLymeData patient registry run by LymeDisease.org, which has documented patient-experienced efficacy of alternative treatments and described antibiotic responders and nonresponders.

At the workshop, they shared findings alongside academic experts, and researchers called for their continued involvement. “Patient engagement at every step of the research process is critical,” Dr. Nath said.

“We need to ensure that research is reflective of lived experiences … and [that we’re] accelerating clinical trials of therapeutics that are of priority to the patient community,” said Lisa McCorkell, cofounder of the long COVID-focused Patient-Led Research Collaborative.

Ms. McCorkell also called for the creation of an office for infection-associated chronic illnesses in the NIH director’s office. Others voiced their support. “I think it’s a great idea to have an NIH center for infection-associated chronic illnesses,” said Dr. Fallon. “I think it would have a profound impact.”

The other great need, of course, is funding. “We have ideas, we have drugs that can be repurposed, we have a highly informed and engaged community that will enroll in and be retained in studies, and we have outcomes we can measure,” Dr. Deeks said. “What we’re missing is industry engagement and funding. We need massive engagement from the NIH.”
 

Real-world treatment needs

In the meantime, patients are seeking treatment, and “clinicians need to have uncertainty tolerance” and try multiple treatments simultaneously, said David Putrino, PT, PhD, director of rehabilitation innovation for the Mount Sinai Health System and professor of rehabilitation and human performance at the Icahn School of Medicine at Mount Sinai, New York. He oversees a multidisciplinary hybrid clinical care research center that has seen over 1,500 patients with long COVID and is beginning to see patients with other infection-associated chronic illnesses.

Claudia Paul

It’s a model that should be replicated to help fill the “enormous unmet clinical need” of patients with infection-associated chronic illness, said Peter Rowe, MD, professor of pediatrics at the Johns Hopkins School of Medicine and an expert on ME/CFS. And “as we request [more research funding], we will also need [financial] support for clinical care,” he emphasized, to provide equitable access for patients and to attract treating physicians.

Moreover, said Linda Geng, MD, PhD, the culture of stigma needs to change. Right now, patients with long COVID often feel dismissed not only by friends, families, and coworkers, but by clinicians who find it find it hard “to grasp that this is real and a biological condition.”

And it’s not just conditions such as long COVID that are stigmatized, but treatments as well, she said. For instance, some clinicians view low-dose naltrexone, a treatment increasingly being used for inflammation, with suspicion because it is used for opioid use disorder and alcohol use disorder – or because the “low-dose” label summons mistrust of homeopathy. “Even with therapies, there are preconceived notions and biases,” said Dr. Geng, cofounder and codirector of the Stanford (Calif.) Long COVID program.

“What almost killed me,” said Meghan O’Rourke, who has ongoing effects from long-undiagnosed tick-borne illness, “was the invisibility of the illness.” Ms. O’Rourke teaches at Yale University and is the author of “The Invisible Kingdom: Reimagining Chronic Illness.”

Teaching young physicians about these illnesses would help, she and others said. During a question and answer session, Dr. Putrino shared that the Icahn School of Medicine has recently committed to “create a complex chronic illness medical curriculum” that will impact medical education from the first year of medical school through residencies. Dr. Putrino said his team is also working on materials to help other clinics develop care models similar to those at his Mount Sinai clinic.

The NASEM workshop did not collect or require disclosures of its participants.

Experience with long COVID has shone a spotlight on persistent Lyme disease and other often debilitating chronic illnesses that follow known or suspected infections – and on the urgent need for a common and well-funded research agenda, education of physicians, growth of multidisciplinary clinics, and financially supported clinical care.

“We critically need to understand the epidemiology and pathogenesis of chronic symptoms, and identify more effective ways to manage, treat, and potentially cure these illnesses,” Lyle Petersen, MD, MPH, director of the division of vector-borne diseases at the Centers for Disease Control and Prevention, said at the start of a 2-day National Academies of Science, Engineering, and Medicine (NASEM) workshop, “Toward a Common Research Agenda in Infection-Associated Chronic Illnesses.”

Thinking about infection-associated chronic illnesses as an entity – one predicated on commonalities in chronic symptoms and in leading hypotheses for causes – represents a paradigm shift that researchers and patient advocates said can avoid research redundancies and is essential to address what the NASEM calls an overlooked, growing public health problem.

An estimated 2 million people in the United States are living with what’s called posttreatment Lyme disease (PTLD) – a subset of patients with persistent or chronic Lyme disease – and an estimated 1.7-3.3 million people in the United States have diagnoses of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). More than 700,000 people are living with multiple sclerosis. And as of January 2023, 11% of people in the United States reported having long COVID symptoms; the incidence of long COVID is currently estimated at 10%-30% of nonhospitalized cases of COVID-19.

These illnesses “have come under one umbrella,” said Avindra Nath, MD, clinical director of the National Institute of Neurologic Disorders and Stroke (NINDS), Bethesda, Md.

Dr. Nath

Persistent infection, viral reactivation

RNA viral infections can lead to persistent inflammation and dysregulated immunity, with or without viral persistence over time, Timothy J. Henrich, MD, MMSc, associate professor of medicine at the University of California, San Francisco, said in a keynote address.

Research on Ebola survivors has documented long-lasting inflammation and severe immune dysfunction 2 years after infection, for instance. And it’s well known that HIV-1 leads to aberrant immune responses, inflammation, and organ damage despite antiretroviral therapy, said Dr. Henrich, who leads a laboratory/research group that studies approaches to HIV-1 cure and PET-based imaging approaches to characterize viral reservoirs and immune sequelae.

Viral persistence, which can be difficult to measure, has also been documented in Ebola survivors. And in patients living with HIV-1, HIV-1 RNA and protein expression have been shown to persist, again despite antiretroviral therapy. The UCSF Long-Term Immunological Impact of Novel Coronavirus (LIINC) study, for which Dr. Henrich is the principal investigator, found spike RNA in colorectal tissue more than 22 months post COVID, and other research documented viral protein in gut tissue for up to 6 months, he said.

“I think we’re appreciating now, in at least the scientific and treatment community, that there’s a potential for ‘acute’ infections to exhibit some degree of persistence leading to clinical morbidity,” said Dr. Henrich, one of several speakers to describe reports of pathogen persistence. Regarding long COVID, its “etiology is likely heterogeneous,” he said, but persistence of SARS-CoV-2 “may lay behind” other described mechanisms, from clotting/microvascular dysfunction to inflammation and tissue damage to immune dysregulation.

Reactivation of existing latent viral infections in the setting of new acute microbial illness may also play an etiologic role in chronic illnesses, Dr. Henrich said. Epstein-Barr virus (EBV) reactivation has been shown in some studies, including their UCSF COVID-19 cohort, to be associated with long COVID.

“Physicians have been trained to be skeptical about the role [of latent viral infections],” Michael Peluso, MD, an infectious disease physician and assistant professor at UCSF, said during a talk on viral reactivation. This skepticism needs to be “reexamined and overcome,” he said.

Herpesviruses have frequently been associated with ME/CFS, he noted. And evidence of a strong association between EBV and multiple sclerosis came recently from a prospective study of 10 million military recruits that found a 32-fold increased risk of MS after EBV infection but no increase after infection with other viruses, Dr. Peluso and Dr. Henrich both noted.
 

Research needs, treatment trials

Research needs are vast: The need to learn more about the mechanisms of pathogen persistence and immune evasion, for instance, and the need for more biomarker studies, more imaging studies and tissue analyses, more study of microbiome composition and activity, and continued development and application of metagenomic next-generation sequencing.

Workshop participants also spoke of the need to better understand the molecular mimicry that can occur between pathogen-produced proteins and self-antigens, for instance, and the effects of inflammation and infection-related immune changes on neuronal and microglial function in the brain.

“We should perform similar forms of analysis [across] patients with different infection-associated chronic conditions,” said Amy Proal, PhD, president of the PolyBio Research Foundation, which funds research on infection-associated chronic infections. And within individual conditions and well-characterized study groups “we should perform many different forms of analysis … so we can define endotypes and get more solid biomarkers so that industry [will have more confidence] to run clinical trials.”

In the meantime, patients need fast-moving treatment trials for long COVID, long Lyme, and other infection-associated chronic illnesses, speakers emphasized. “We all agree that treatment trials are overdue,” said the NINDS’ Dr. Nath. “We can’t afford to wait for another decade until we understand all the mechanisms, but rather we can do clinical trials based on what we understand now and study the pathophysiology in the context of the clinical trials.”

Just as was done with HIV, said Steven G. Deeks, MD, professor of medicine at UCSF, researchers must “practice experimental medicine” and select pathways and mechanisms of interest, interrupt those pathways in a controlled manner, and assess impact. “Much of this can be done by repurposing existing drugs,” he said, like antivirals for persistent viral infection, EBV-directed therapies for EBV reactivation, anti-inflammatory drugs for inflammation, B–cell-directed therapies for autoantibodies, and antiplatelet drugs for microvascular disease.

When done correctly, he said, such “probe” studies can deepen mechanistic understandings, lead to biomarkers, and provide proof-of-concept that “will encourage massive investment in developing new therapies” for long COVID and other infection-associated chronic illnesses.

Trials of treatments for long COVID “are starting, so I’m optimistic,” said Dr. Deeks, an expert on HIV pathogenesis and treatment and a principal investigator of the Researching COVID to Enhance Recovery (RECOVER) study. Among the trials: A study of intravenous immunoglobulin (IVIG) for neurologic long COVID; a study of an anti-SARS-CoV-2 monoclonal antibody that can deplete tissue/cellular reservoirs of viral particles (replicating or not); and a study evaluating baricitinib (Olumiant), a Janus kinase inhibitor, for neurocognitive impairment and cardiopulmonary symptoms of long COVID.

Alessio Fasano, MD, professor of pediatrics at Harvard Medical School and professor of nutrition at the Harvard T.H. Chan School of Public Health, Boston, described at the workshop how he began investigating the use of larazotide acetate – an inhibitor of the protein zonulin, which increases intestinal permeability – in children with COVID-19 Multisystem Inflammatory Syndrome (MIS-C) after learning that SARS-CoV-2 viral particles persist in the gastrointestinal tract, causing dysbiosis and zonulin upregulation.

In an ongoing phase 2, double-blind, placebo-controlled trial, the agent thus far has expedited the resolution of gastrointestinal symptoms and clearance of spike protein from the circulation, he said. A phase 2 trial of the agent for pediatric patients with long COVID and SARS-CoV-2 antigenemia is underway. “What if we were to stop [chains of events] by stopping the passage of elements from the virus into circulation?’ he said.

In the realm of Lyme disease, a recently launched Clinical Trials Network for Lyme and Other Tick-Borne Diseases has awarded pilot study grants to evaluate treatments aimed at a variety of possible disease mechanisms that, notably, are similar to those of other chronic illnesses: persistence of infection or remnants of infection, immune dysregulation and autoimmune reactions, neural dysfunction, and gut microbiome changes. (Microclots and mitochondrial dysfunction have not been as well studied in Lyme.)

Current and upcoming studies include evaluations of transcutaneous auricular vagus nerve stimulation for those with persistent Lyme fatigue, transcranial direct current stimulation with cognitive retraining for Lyme brain fog, and tetracycline for PTLD, said Brian Fallon, MD, MPH, professor of clinical psychiatry at Columbia University, New York, who directs the Lyme & Tick-Borne Diseases Research Center and the coordinating center of the new network.

Columbia University Irving Medical Center

Calls for a new NIH center and patient involvement

Patients and patient advocacy organizations have played a vital role in research thus far: They’ve documented post-COVID symptoms that academic researchers said they would not otherwise have known of. Leaders of the Patient-Led Research Collaborative have coauthored published reviews with leading long COVID experts. And patients with tick-borne illnesses have enrolled in the MyLymeData patient registry run by LymeDisease.org, which has documented patient-experienced efficacy of alternative treatments and described antibiotic responders and nonresponders.

At the workshop, they shared findings alongside academic experts, and researchers called for their continued involvement. “Patient engagement at every step of the research process is critical,” Dr. Nath said.

“We need to ensure that research is reflective of lived experiences … and [that we’re] accelerating clinical trials of therapeutics that are of priority to the patient community,” said Lisa McCorkell, cofounder of the long COVID-focused Patient-Led Research Collaborative.

Ms. McCorkell also called for the creation of an office for infection-associated chronic illnesses in the NIH director’s office. Others voiced their support. “I think it’s a great idea to have an NIH center for infection-associated chronic illnesses,” said Dr. Fallon. “I think it would have a profound impact.”

The other great need, of course, is funding. “We have ideas, we have drugs that can be repurposed, we have a highly informed and engaged community that will enroll in and be retained in studies, and we have outcomes we can measure,” Dr. Deeks said. “What we’re missing is industry engagement and funding. We need massive engagement from the NIH.”
 

Real-world treatment needs

In the meantime, patients are seeking treatment, and “clinicians need to have uncertainty tolerance” and try multiple treatments simultaneously, said David Putrino, PT, PhD, director of rehabilitation innovation for the Mount Sinai Health System and professor of rehabilitation and human performance at the Icahn School of Medicine at Mount Sinai, New York. He oversees a multidisciplinary hybrid clinical care research center that has seen over 1,500 patients with long COVID and is beginning to see patients with other infection-associated chronic illnesses.

Claudia Paul

It’s a model that should be replicated to help fill the “enormous unmet clinical need” of patients with infection-associated chronic illness, said Peter Rowe, MD, professor of pediatrics at the Johns Hopkins School of Medicine and an expert on ME/CFS. And “as we request [more research funding], we will also need [financial] support for clinical care,” he emphasized, to provide equitable access for patients and to attract treating physicians.

Moreover, said Linda Geng, MD, PhD, the culture of stigma needs to change. Right now, patients with long COVID often feel dismissed not only by friends, families, and coworkers, but by clinicians who find it find it hard “to grasp that this is real and a biological condition.”

And it’s not just conditions such as long COVID that are stigmatized, but treatments as well, she said. For instance, some clinicians view low-dose naltrexone, a treatment increasingly being used for inflammation, with suspicion because it is used for opioid use disorder and alcohol use disorder – or because the “low-dose” label summons mistrust of homeopathy. “Even with therapies, there are preconceived notions and biases,” said Dr. Geng, cofounder and codirector of the Stanford (Calif.) Long COVID program.

“What almost killed me,” said Meghan O’Rourke, who has ongoing effects from long-undiagnosed tick-borne illness, “was the invisibility of the illness.” Ms. O’Rourke teaches at Yale University and is the author of “The Invisible Kingdom: Reimagining Chronic Illness.”

Teaching young physicians about these illnesses would help, she and others said. During a question and answer session, Dr. Putrino shared that the Icahn School of Medicine has recently committed to “create a complex chronic illness medical curriculum” that will impact medical education from the first year of medical school through residencies. Dr. Putrino said his team is also working on materials to help other clinics develop care models similar to those at his Mount Sinai clinic.

The NASEM workshop did not collect or require disclosures of its participants.

Several recent developments in Lyme disease treatment and diagnosis may pave the way forward for combating disease that persists following missed or delayed diagnoses or remains following standard treatment. These include combination therapy to address “persister” bacteria and diagnostic tests that test directly for the pathogen and/or indirectly test for host response, according to experts who presented at a 2-day National Academies of Science, Engineering and Medicine workshop on infection-associated chronic illnesses.

Research has shown that 60% of people who are infected and not treated during the early or early disseminated stages of Lyme disease go on to develop late Lyme arthritis, said John Aucott, MD, director of the Johns Hopkins Lyme Disease Clinical Research Center in Baltimore. And in the real world, there’s an additional category of patients: Those who are misdiagnosed and develop infection-related persistent symptoms – such as fatigue, brain fog/cognitive dysfunction, and musculoskeletal problems – that don’t match the “textbook schematic” involving late Lyme arthritis and late neurologic disease.

Moreover, of patients who are treated with protocols recommended by the Infectious Diseases Society of America (IDSA), about 15% go on to develop persistent symptoms at 6 months – again, symptoms that don’t match textbook manifestations and do match symptoms of other infection-associated chronic illnesses. As a “research construct,” this has been coined posttreatment Lyme disease (PTLD), he said at the workshop, “Toward a Common Research Agenda in Infection-Associated Chronic Illnesses.”

(On a practical level, it is hard to know clinically who has early disseminated disease unless they have multiple erythema migrans rashes or neurologic or cardiac involvement, he said after the meeting.)

All this points to the need for tests that are sensitive and specific for diagnosis at all stages of infection and disease, he said in a talk on diagnostics. Currently available tests – those that fit into the widely used two-tiered enzyme-linked immunosorbent assay, Western Blot serology testing – have significant limitations in sensitivity and specificity, including for acute infection when the body has not generated enough antibodies, yet treatment is most likely to succeed.
 

Move toward combination therapy research

Lyme disease is most commonly treated with doxycycline, and that’s problematic because the antibiotic is a microstatic whose efficacy relies on immune clearance of static bacteria, said Monica E. Embers, PhD, director of vector-borne disease at the Tulane National Primate Research Center and associate professor of immunology at Tulane University, New Orleans.

courtesy Tulane University-Paula Burch-Celentano

“But we know that Borrelia burgdorferi has the capability to evade the host immune response in almost every way possible. Persistence is the norm in an immunocompetent host ... [and] dormant bacteria/persisters are more tolerant of microstatic antibiotics,” she said.

Other considerations for antibiotic efficacy include the fact that B. burgdorferi survives for many months inside ticks without nutrient replenishment or replication, “so dormancy is part of their life cycle,” she said. Moreover, the bacteria can be found deep in connective tissues and joints.

The efficacy of accepted regimens of antibiotic treatment has been “a very contentious issue,” she said, noting that guidelines from the International Lyme and Associated Diseases Society “leave open the possibility for antibiotic retreatment when a chronic infection is judged to be a possible cause [of ongoing symptoms].”

The development of persister B. burgdorferi in the presence of antibiotics has been well studied in vitro, which has limitations, Dr. Embers said. But her group specializes in animal models and has shown persistence of antimicrobial-tolerant B. burgdorferi in tick-inoculated rhesus macaques 8-9 months after treatment with oral doxycycline.

“We [also] saw persistence of mild-moderate inflammation in the brain, peripheral nerves, spinal cord, joints and skeletal muscle, and in the heart,” Dr. Embers said, who coauthored a 2022 review of B. burgdorferi antimicrobial-tolerant persistence in Lyme disease and PTLD.

Her work has also shown that ceftriaxone, which is recommended by IDSA for patients with clinically evident neurological and/or cardiac involvement, does not clear infection in mice. “In general, single drugs have not been capable of clearing the infection, yet combinations show promise,” she said.

Dr. Embers has combed large drug libraries looking for combinations of antibiotics that employ different mechanisms of action in hopes of eliminating persister spirochetes. Certain combinations have shown promise in mice and have been tested in her rhesus macaque model; data analyses are underway.

Other research teams, such as that of Ying Zhang, MD, PhD, at Johns Hopkins, have similarly been screening combinations of antibiotics and other compounds, identifying candidates for further testing.

During a question and answer period, Dr. Embers said her team is also investigating the pathophysiology and long-term effects of tick-borne coinfections, including Bartonella, and is pursuing a hypothesis that infection with Borrelia allows Bartonella to cause more extensive disease and persist longer. “I think Lyme is at the core because of its ability to evade and suppress the immune response so effectively.”
 

Diagnostic possibilities, biomarkers for PTLD

Direct diagnostic tests for microbial nucleic acid and proteins “are promising alternatives for indirect serologic tests,” Dr. Aucott said. For instance, in addition to polymerase chain reaction tests, which “are making advances,” it may be possible to target the B. burgdorferi peptidoglycan for antigen detection.

Researchers have shown that peptidoglycan, a component of the B. burgdorferi cell envelope, is a persistent antigen in the synovial fluid of patients with Lyme arthritis who have been treated with oral and intravenous antibiotics, and that it likely contributes to inflammation.

“Maybe the infection is gone but parts of the bacteria are still there that are driving inflammation,” said Dr. Aucott, also associate professor of medicine at John Hopkins.

Researchers have also been looking at the host response to B. burgdorferi – including cytokines, chemokines, and autoantibiodies – to identify biomarkers for PTLD and to identify patients during posttreatment follow-up who are at increased risk of developing PTLD, with the hope of someday intervening. Persistently high levels of interleukin-23, CCL19, and interferon-alpha have each been associated in different studies with persistent symptoms after treatment, Dr. Aucott said.

In addition, metabolomics research is showing that patients with PTLD have metabolic fingerprints that are different from those who return to good health after treatment, and it may be possible to identify an epigenetic signature for Lyme disease. A project sponsored by the Defense Advanced Research Projects Agency called ECHO (Epigenetic Characterization and Observation) aims to identify epigenetic signatures of exposures to various threats, including B. burgdorferi.

“At the very proximal end of [indirectly testing for host response], there are modifications of the DNA that can occur in response to infectious insults ... and that changed DNA changes RNA expression and protein synthesis,” Dr. Aucott explained. DARPA’s project is “exciting because their goal [at DARPA] is to have a diagnostic test quickly as a result of this epigenetics work.”

Imaging research is also fast offering diagnostic opportunities, Dr. Aucott said. Levels of microglial activation on brain PET imaging have been found to correlate with PTLD, and a study at Johns Hopkins of multimodal neuroimaging with functional MRI and diffusion tensor imaging has shown distinct changes to white matter activation within the frontal lobe of patients with PTLD, compared with controls.

The NASEM workshop did not collect or require disclosures of its participants.

Several recent developments in Lyme disease treatment and diagnosis may pave the way forward for combating disease that persists following missed or delayed diagnoses or remains following standard treatment. These include combination therapy to address “persister” bacteria and diagnostic tests that test directly for the pathogen and/or indirectly test for host response, according to experts who presented at a 2-day National Academies of Science, Engineering and Medicine workshop on infection-associated chronic illnesses.

Research has shown that 60% of people who are infected and not treated during the early or early disseminated stages of Lyme disease go on to develop late Lyme arthritis, said John Aucott, MD, director of the Johns Hopkins Lyme Disease Clinical Research Center in Baltimore. And in the real world, there’s an additional category of patients: Those who are misdiagnosed and develop infection-related persistent symptoms – such as fatigue, brain fog/cognitive dysfunction, and musculoskeletal problems – that don’t match the “textbook schematic” involving late Lyme arthritis and late neurologic disease.

Moreover, of patients who are treated with protocols recommended by the Infectious Diseases Society of America (IDSA), about 15% go on to develop persistent symptoms at 6 months – again, symptoms that don’t match textbook manifestations and do match symptoms of other infection-associated chronic illnesses. As a “research construct,” this has been coined posttreatment Lyme disease (PTLD), he said at the workshop, “Toward a Common Research Agenda in Infection-Associated Chronic Illnesses.”

(On a practical level, it is hard to know clinically who has early disseminated disease unless they have multiple erythema migrans rashes or neurologic or cardiac involvement, he said after the meeting.)

All this points to the need for tests that are sensitive and specific for diagnosis at all stages of infection and disease, he said in a talk on diagnostics. Currently available tests – those that fit into the widely used two-tiered enzyme-linked immunosorbent assay, Western Blot serology testing – have significant limitations in sensitivity and specificity, including for acute infection when the body has not generated enough antibodies, yet treatment is most likely to succeed.
 

Move toward combination therapy research

Lyme disease is most commonly treated with doxycycline, and that’s problematic because the antibiotic is a microstatic whose efficacy relies on immune clearance of static bacteria, said Monica E. Embers, PhD, director of vector-borne disease at the Tulane National Primate Research Center and associate professor of immunology at Tulane University, New Orleans.

courtesy Tulane University-Paula Burch-Celentano

“But we know that Borrelia burgdorferi has the capability to evade the host immune response in almost every way possible. Persistence is the norm in an immunocompetent host ... [and] dormant bacteria/persisters are more tolerant of microstatic antibiotics,” she said.

Other considerations for antibiotic efficacy include the fact that B. burgdorferi survives for many months inside ticks without nutrient replenishment or replication, “so dormancy is part of their life cycle,” she said. Moreover, the bacteria can be found deep in connective tissues and joints.

The efficacy of accepted regimens of antibiotic treatment has been “a very contentious issue,” she said, noting that guidelines from the International Lyme and Associated Diseases Society “leave open the possibility for antibiotic retreatment when a chronic infection is judged to be a possible cause [of ongoing symptoms].”

The development of persister B. burgdorferi in the presence of antibiotics has been well studied in vitro, which has limitations, Dr. Embers said. But her group specializes in animal models and has shown persistence of antimicrobial-tolerant B. burgdorferi in tick-inoculated rhesus macaques 8-9 months after treatment with oral doxycycline.

“We [also] saw persistence of mild-moderate inflammation in the brain, peripheral nerves, spinal cord, joints and skeletal muscle, and in the heart,” Dr. Embers said, who coauthored a 2022 review of B. burgdorferi antimicrobial-tolerant persistence in Lyme disease and PTLD.

Her work has also shown that ceftriaxone, which is recommended by IDSA for patients with clinically evident neurological and/or cardiac involvement, does not clear infection in mice. “In general, single drugs have not been capable of clearing the infection, yet combinations show promise,” she said.

Dr. Embers has combed large drug libraries looking for combinations of antibiotics that employ different mechanisms of action in hopes of eliminating persister spirochetes. Certain combinations have shown promise in mice and have been tested in her rhesus macaque model; data analyses are underway.

Other research teams, such as that of Ying Zhang, MD, PhD, at Johns Hopkins, have similarly been screening combinations of antibiotics and other compounds, identifying candidates for further testing.

During a question and answer period, Dr. Embers said her team is also investigating the pathophysiology and long-term effects of tick-borne coinfections, including Bartonella, and is pursuing a hypothesis that infection with Borrelia allows Bartonella to cause more extensive disease and persist longer. “I think Lyme is at the core because of its ability to evade and suppress the immune response so effectively.”
 

Diagnostic possibilities, biomarkers for PTLD

Direct diagnostic tests for microbial nucleic acid and proteins “are promising alternatives for indirect serologic tests,” Dr. Aucott said. For instance, in addition to polymerase chain reaction tests, which “are making advances,” it may be possible to target the B. burgdorferi peptidoglycan for antigen detection.

Researchers have shown that peptidoglycan, a component of the B. burgdorferi cell envelope, is a persistent antigen in the synovial fluid of patients with Lyme arthritis who have been treated with oral and intravenous antibiotics, and that it likely contributes to inflammation.

“Maybe the infection is gone but parts of the bacteria are still there that are driving inflammation,” said Dr. Aucott, also associate professor of medicine at John Hopkins.

Researchers have also been looking at the host response to B. burgdorferi – including cytokines, chemokines, and autoantibiodies – to identify biomarkers for PTLD and to identify patients during posttreatment follow-up who are at increased risk of developing PTLD, with the hope of someday intervening. Persistently high levels of interleukin-23, CCL19, and interferon-alpha have each been associated in different studies with persistent symptoms after treatment, Dr. Aucott said.

In addition, metabolomics research is showing that patients with PTLD have metabolic fingerprints that are different from those who return to good health after treatment, and it may be possible to identify an epigenetic signature for Lyme disease. A project sponsored by the Defense Advanced Research Projects Agency called ECHO (Epigenetic Characterization and Observation) aims to identify epigenetic signatures of exposures to various threats, including B. burgdorferi.

“At the very proximal end of [indirectly testing for host response], there are modifications of the DNA that can occur in response to infectious insults ... and that changed DNA changes RNA expression and protein synthesis,” Dr. Aucott explained. DARPA’s project is “exciting because their goal [at DARPA] is to have a diagnostic test quickly as a result of this epigenetics work.”

Imaging research is also fast offering diagnostic opportunities, Dr. Aucott said. Levels of microglial activation on brain PET imaging have been found to correlate with PTLD, and a study at Johns Hopkins of multimodal neuroimaging with functional MRI and diffusion tensor imaging has shown distinct changes to white matter activation within the frontal lobe of patients with PTLD, compared with controls.

The NASEM workshop did not collect or require disclosures of its participants.

Several recent developments in Lyme disease treatment and diagnosis may pave the way forward for combating disease that persists following missed or delayed diagnoses or remains following standard treatment. These include combination therapy to address “persister” bacteria and diagnostic tests that test directly for the pathogen and/or indirectly test for host response, according to experts who presented at a 2-day National Academies of Science, Engineering and Medicine workshop on infection-associated chronic illnesses.

Research has shown that 60% of people who are infected and not treated during the early or early disseminated stages of Lyme disease go on to develop late Lyme arthritis, said John Aucott, MD, director of the Johns Hopkins Lyme Disease Clinical Research Center in Baltimore. And in the real world, there’s an additional category of patients: Those who are misdiagnosed and develop infection-related persistent symptoms – such as fatigue, brain fog/cognitive dysfunction, and musculoskeletal problems – that don’t match the “textbook schematic” involving late Lyme arthritis and late neurologic disease.

Moreover, of patients who are treated with protocols recommended by the Infectious Diseases Society of America (IDSA), about 15% go on to develop persistent symptoms at 6 months – again, symptoms that don’t match textbook manifestations and do match symptoms of other infection-associated chronic illnesses. As a “research construct,” this has been coined posttreatment Lyme disease (PTLD), he said at the workshop, “Toward a Common Research Agenda in Infection-Associated Chronic Illnesses.”

(On a practical level, it is hard to know clinically who has early disseminated disease unless they have multiple erythema migrans rashes or neurologic or cardiac involvement, he said after the meeting.)

All this points to the need for tests that are sensitive and specific for diagnosis at all stages of infection and disease, he said in a talk on diagnostics. Currently available tests – those that fit into the widely used two-tiered enzyme-linked immunosorbent assay, Western Blot serology testing – have significant limitations in sensitivity and specificity, including for acute infection when the body has not generated enough antibodies, yet treatment is most likely to succeed.
 

Move toward combination therapy research

Lyme disease is most commonly treated with doxycycline, and that’s problematic because the antibiotic is a microstatic whose efficacy relies on immune clearance of static bacteria, said Monica E. Embers, PhD, director of vector-borne disease at the Tulane National Primate Research Center and associate professor of immunology at Tulane University, New Orleans.

courtesy Tulane University-Paula Burch-Celentano

“But we know that Borrelia burgdorferi has the capability to evade the host immune response in almost every way possible. Persistence is the norm in an immunocompetent host ... [and] dormant bacteria/persisters are more tolerant of microstatic antibiotics,” she said.

Other considerations for antibiotic efficacy include the fact that B. burgdorferi survives for many months inside ticks without nutrient replenishment or replication, “so dormancy is part of their life cycle,” she said. Moreover, the bacteria can be found deep in connective tissues and joints.

The efficacy of accepted regimens of antibiotic treatment has been “a very contentious issue,” she said, noting that guidelines from the International Lyme and Associated Diseases Society “leave open the possibility for antibiotic retreatment when a chronic infection is judged to be a possible cause [of ongoing symptoms].”

The development of persister B. burgdorferi in the presence of antibiotics has been well studied in vitro, which has limitations, Dr. Embers said. But her group specializes in animal models and has shown persistence of antimicrobial-tolerant B. burgdorferi in tick-inoculated rhesus macaques 8-9 months after treatment with oral doxycycline.

“We [also] saw persistence of mild-moderate inflammation in the brain, peripheral nerves, spinal cord, joints and skeletal muscle, and in the heart,” Dr. Embers said, who coauthored a 2022 review of B. burgdorferi antimicrobial-tolerant persistence in Lyme disease and PTLD.

Her work has also shown that ceftriaxone, which is recommended by IDSA for patients with clinically evident neurological and/or cardiac involvement, does not clear infection in mice. “In general, single drugs have not been capable of clearing the infection, yet combinations show promise,” she said.

Dr. Embers has combed large drug libraries looking for combinations of antibiotics that employ different mechanisms of action in hopes of eliminating persister spirochetes. Certain combinations have shown promise in mice and have been tested in her rhesus macaque model; data analyses are underway.

Other research teams, such as that of Ying Zhang, MD, PhD, at Johns Hopkins, have similarly been screening combinations of antibiotics and other compounds, identifying candidates for further testing.

During a question and answer period, Dr. Embers said her team is also investigating the pathophysiology and long-term effects of tick-borne coinfections, including Bartonella, and is pursuing a hypothesis that infection with Borrelia allows Bartonella to cause more extensive disease and persist longer. “I think Lyme is at the core because of its ability to evade and suppress the immune response so effectively.”
 

Diagnostic possibilities, biomarkers for PTLD

Direct diagnostic tests for microbial nucleic acid and proteins “are promising alternatives for indirect serologic tests,” Dr. Aucott said. For instance, in addition to polymerase chain reaction tests, which “are making advances,” it may be possible to target the B. burgdorferi peptidoglycan for antigen detection.

Researchers have shown that peptidoglycan, a component of the B. burgdorferi cell envelope, is a persistent antigen in the synovial fluid of patients with Lyme arthritis who have been treated with oral and intravenous antibiotics, and that it likely contributes to inflammation.

“Maybe the infection is gone but parts of the bacteria are still there that are driving inflammation,” said Dr. Aucott, also associate professor of medicine at John Hopkins.

Researchers have also been looking at the host response to B. burgdorferi – including cytokines, chemokines, and autoantibiodies – to identify biomarkers for PTLD and to identify patients during posttreatment follow-up who are at increased risk of developing PTLD, with the hope of someday intervening. Persistently high levels of interleukin-23, CCL19, and interferon-alpha have each been associated in different studies with persistent symptoms after treatment, Dr. Aucott said.

In addition, metabolomics research is showing that patients with PTLD have metabolic fingerprints that are different from those who return to good health after treatment, and it may be possible to identify an epigenetic signature for Lyme disease. A project sponsored by the Defense Advanced Research Projects Agency called ECHO (Epigenetic Characterization and Observation) aims to identify epigenetic signatures of exposures to various threats, including B. burgdorferi.

“At the very proximal end of [indirectly testing for host response], there are modifications of the DNA that can occur in response to infectious insults ... and that changed DNA changes RNA expression and protein synthesis,” Dr. Aucott explained. DARPA’s project is “exciting because their goal [at DARPA] is to have a diagnostic test quickly as a result of this epigenetics work.”

Imaging research is also fast offering diagnostic opportunities, Dr. Aucott said. Levels of microglial activation on brain PET imaging have been found to correlate with PTLD, and a study at Johns Hopkins of multimodal neuroimaging with functional MRI and diffusion tensor imaging has shown distinct changes to white matter activation within the frontal lobe of patients with PTLD, compared with controls.

The NASEM workshop did not collect or require disclosures of its participants.

An estimated 3 in every 10 white-tailed deer in the United States have had COVID-19, and new research suggests deer populations could be a source of virus mutations that may be passed to humans.

According to the U.S. Department of Agriculture, which led the research project, humans transmitted the virus to deer at least 100 times. The virus then spread widely among free-ranging deer populations, and there were three possible cases of the deer transmitting the virus to humans.

The data comes from tests done between November 2021 and April 2022 on more than 12,000 deer found across half of the United States. Sequencing of the virus found in the deer showed that deer had been exposed to all of the prominent variants, including Alpha, Gamma, Delta, and Omicron.

Some of the findings about transmission were published in the journal Nature Communications, in which researchers noted that in addition to being identified in deer, the virus has been found in wild and domestic animals, including mink, rats, otters, ferrets, hamsters, gorillas, cats, dogs, lions, and tigers. Animal-to-human transmission has been documented or suspected in mink and domestic cats, in addition to white-tailed deer.

The findings are important because the animal populations can become “reservoirs ... in which the virus circulates covertly, persisting in the population and can be transmitted to other animals or humans potentially causing disease outbreaks,” according to the paper, which was a collaboration among scientists from the U.S. Department of Agriculture, CDC, and the University of Missouri–Columbia.

In the three cases of possible deer-to-human transmission, researchers said that mutated versions of the virus previously found only in deer had been found in COVID test samples taken from one person in North Carolina and two people in Massachusetts. Those deer-specific mutated versions of the virus have not been found in any other human samples, lending evidence that the mutations occurred within deer.

“Deer regularly interact with humans and are commonly found in human environments – near our homes, pets, wastewater, and trash,” researcher and University of Missouri–Columbia professor Xiu-Feng “Henry” Wan, PhD, said in a statement. “The potential for SARS-CoV-2, or any zoonotic disease, to persist and evolve in wildlife populations can pose unique public health risks.”

In the Nature Communications paper, the researchers suggested that deer may be exposed to the virus from human food waste, masks, or other waste products. The authors concluded that further study is needed to determine how virus transmission occurs between deer and humans.

A version of this article first appeared on WebMD.com.

An estimated 3 in every 10 white-tailed deer in the United States have had COVID-19, and new research suggests deer populations could be a source of virus mutations that may be passed to humans.

According to the U.S. Department of Agriculture, which led the research project, humans transmitted the virus to deer at least 100 times. The virus then spread widely among free-ranging deer populations, and there were three possible cases of the deer transmitting the virus to humans.

The data comes from tests done between November 2021 and April 2022 on more than 12,000 deer found across half of the United States. Sequencing of the virus found in the deer showed that deer had been exposed to all of the prominent variants, including Alpha, Gamma, Delta, and Omicron.

Some of the findings about transmission were published in the journal Nature Communications, in which researchers noted that in addition to being identified in deer, the virus has been found in wild and domestic animals, including mink, rats, otters, ferrets, hamsters, gorillas, cats, dogs, lions, and tigers. Animal-to-human transmission has been documented or suspected in mink and domestic cats, in addition to white-tailed deer.

The findings are important because the animal populations can become “reservoirs ... in which the virus circulates covertly, persisting in the population and can be transmitted to other animals or humans potentially causing disease outbreaks,” according to the paper, which was a collaboration among scientists from the U.S. Department of Agriculture, CDC, and the University of Missouri–Columbia.

In the three cases of possible deer-to-human transmission, researchers said that mutated versions of the virus previously found only in deer had been found in COVID test samples taken from one person in North Carolina and two people in Massachusetts. Those deer-specific mutated versions of the virus have not been found in any other human samples, lending evidence that the mutations occurred within deer.

“Deer regularly interact with humans and are commonly found in human environments – near our homes, pets, wastewater, and trash,” researcher and University of Missouri–Columbia professor Xiu-Feng “Henry” Wan, PhD, said in a statement. “The potential for SARS-CoV-2, or any zoonotic disease, to persist and evolve in wildlife populations can pose unique public health risks.”

In the Nature Communications paper, the researchers suggested that deer may be exposed to the virus from human food waste, masks, or other waste products. The authors concluded that further study is needed to determine how virus transmission occurs between deer and humans.

A version of this article first appeared on WebMD.com.

An estimated 3 in every 10 white-tailed deer in the United States have had COVID-19, and new research suggests deer populations could be a source of virus mutations that may be passed to humans.

According to the U.S. Department of Agriculture, which led the research project, humans transmitted the virus to deer at least 100 times. The virus then spread widely among free-ranging deer populations, and there were three possible cases of the deer transmitting the virus to humans.

The data comes from tests done between November 2021 and April 2022 on more than 12,000 deer found across half of the United States. Sequencing of the virus found in the deer showed that deer had been exposed to all of the prominent variants, including Alpha, Gamma, Delta, and Omicron.

Some of the findings about transmission were published in the journal Nature Communications, in which researchers noted that in addition to being identified in deer, the virus has been found in wild and domestic animals, including mink, rats, otters, ferrets, hamsters, gorillas, cats, dogs, lions, and tigers. Animal-to-human transmission has been documented or suspected in mink and domestic cats, in addition to white-tailed deer.

The findings are important because the animal populations can become “reservoirs ... in which the virus circulates covertly, persisting in the population and can be transmitted to other animals or humans potentially causing disease outbreaks,” according to the paper, which was a collaboration among scientists from the U.S. Department of Agriculture, CDC, and the University of Missouri–Columbia.

In the three cases of possible deer-to-human transmission, researchers said that mutated versions of the virus previously found only in deer had been found in COVID test samples taken from one person in North Carolina and two people in Massachusetts. Those deer-specific mutated versions of the virus have not been found in any other human samples, lending evidence that the mutations occurred within deer.

“Deer regularly interact with humans and are commonly found in human environments – near our homes, pets, wastewater, and trash,” researcher and University of Missouri–Columbia professor Xiu-Feng “Henry” Wan, PhD, said in a statement. “The potential for SARS-CoV-2, or any zoonotic disease, to persist and evolve in wildlife populations can pose unique public health risks.”

In the Nature Communications paper, the researchers suggested that deer may be exposed to the virus from human food waste, masks, or other waste products. The authors concluded that further study is needed to determine how virus transmission occurs between deer and humans.

A version of this article first appeared on WebMD.com.

It turns out that some people really are tick magnets.

Researchers have discovered that ticks can defy gravity in their quest to latch onto people and animals. The key is static electricity, just like when someone rubs a balloon and things stick to it.

The study was published in the journal Current Biology. In the first phase of the research, scientists exposed ticks to furry rabbit feet and to acrylic surfaces that each had electrostatic charges.

“Ticks were readily attracted across air gaps of up to several millimeters or centimeters onto these statically charged surfaces,” the authors wrote. “This establishes that electrostatic attraction of ticks onto hosts can take place over large air gaps of many body lengths of a tick.”

In a second part of the study, the researchers created computer models simulating the electrostatic charges that exist in environments where both ticks and mammals are found. In one simulation, the researchers observed that the body parts of a cow with the most electric charge were the nose, tail, and legs, which are the body parts most likely to be encountered by a tick. They also found that the vegetation near the animal had a strong electric field that is just a few millimeters wide.

In a final phase of the study, the researchers conducted laboratory experiments in which they re-created the electric field conditions from the computer model and successfully lifted some ticks across an air gap, although some ticks did not make the full leap if they were observed to be resisting.

The authors noted that their findings could be applied to developing new tick prevention strategies, such as designing clothing that resists electrostatic charges or spraying livestock.

The study authors reported that they had no conflicts of interest.

A version of this article first appeared on WebMD.com.

It turns out that some people really are tick magnets.

Researchers have discovered that ticks can defy gravity in their quest to latch onto people and animals. The key is static electricity, just like when someone rubs a balloon and things stick to it.

The study was published in the journal Current Biology. In the first phase of the research, scientists exposed ticks to furry rabbit feet and to acrylic surfaces that each had electrostatic charges.

“Ticks were readily attracted across air gaps of up to several millimeters or centimeters onto these statically charged surfaces,” the authors wrote. “This establishes that electrostatic attraction of ticks onto hosts can take place over large air gaps of many body lengths of a tick.”

In a second part of the study, the researchers created computer models simulating the electrostatic charges that exist in environments where both ticks and mammals are found. In one simulation, the researchers observed that the body parts of a cow with the most electric charge were the nose, tail, and legs, which are the body parts most likely to be encountered by a tick. They also found that the vegetation near the animal had a strong electric field that is just a few millimeters wide.

In a final phase of the study, the researchers conducted laboratory experiments in which they re-created the electric field conditions from the computer model and successfully lifted some ticks across an air gap, although some ticks did not make the full leap if they were observed to be resisting.

The authors noted that their findings could be applied to developing new tick prevention strategies, such as designing clothing that resists electrostatic charges or spraying livestock.

The study authors reported that they had no conflicts of interest.

A version of this article first appeared on WebMD.com.

It turns out that some people really are tick magnets.

Researchers have discovered that ticks can defy gravity in their quest to latch onto people and animals. The key is static electricity, just like when someone rubs a balloon and things stick to it.

The study was published in the journal Current Biology. In the first phase of the research, scientists exposed ticks to furry rabbit feet and to acrylic surfaces that each had electrostatic charges.

“Ticks were readily attracted across air gaps of up to several millimeters or centimeters onto these statically charged surfaces,” the authors wrote. “This establishes that electrostatic attraction of ticks onto hosts can take place over large air gaps of many body lengths of a tick.”

In a second part of the study, the researchers created computer models simulating the electrostatic charges that exist in environments where both ticks and mammals are found. In one simulation, the researchers observed that the body parts of a cow with the most electric charge were the nose, tail, and legs, which are the body parts most likely to be encountered by a tick. They also found that the vegetation near the animal had a strong electric field that is just a few millimeters wide.

In a final phase of the study, the researchers conducted laboratory experiments in which they re-created the electric field conditions from the computer model and successfully lifted some ticks across an air gap, although some ticks did not make the full leap if they were observed to be resisting.

The authors noted that their findings could be applied to developing new tick prevention strategies, such as designing clothing that resists electrostatic charges or spraying livestock.

The study authors reported that they had no conflicts of interest.

A version of this article first appeared on WebMD.com.

Researchers using a modeling study of rabies in the United States have quantified the risk of death and exposure and estimated a threshold to help health care providers decide when postexposure prophylaxis (PEP) is appropriate.

© astridb05/Fotolia.com

The model, reported in JAMA Network Open, could help clinicians, particularly those in primary care settings, to more rationally prescribe PEP to people concerned about a potential exposure to the rabies virus (RABV). In the United States, rabies PEP often is given without a comprehensive assessment that considers regional factors as well as species, nature of an attack, and the health and vaccination status of the animal.

Providers err on the side of caution, as rabies infection has a fatality rate near 100%. When exposures are low-risk, however, patients can rack up substantial out-of-pocket expenses or experience unnecessary adverse effects from the series of shots. Those can include injection site reactions, hypersensitivity reactions, and neurological complications.

The authors write that an estimated 55,000 people per year in the United States were treated for potential exposure to RABV in 2017 and 2018, at an estimated cost of more than $3,800 per person treated.
 

Researchers calculate risk threshold

The researchers, led by Kelly Charniga, PhD, MPH, an infectious disease epidemiologist with the U.S. Centers for Disease Control and Prevention in Atlanta, calculated positivity rates using more than 900,000 animal samples tested for RABV between 2011 and 2020. Other parameters were estimated from surveillance data and the literature and probabilities were estimated using Bayes’ rule.

A convenience sample of state public health officials in all states (excluding Hawaii) plus Washington and Puerto Rico was used to help determine a risk threshold for recommending PEP. Respondents were asked whether they would recommend PEP given 24 standardized exposure scenarios while accounting for local rabies epidemiology.

Their model establishes a risk threshold of 0.0004 for PEP administration, which represents the probability that an animal would test positive for RABV given that a person was exposed, and the probability that a person would die from rabies after exposure to a suspect rabid animal and no PEP. PEP should not be recommended with any value lower than that cutoff.

Alfred DeMaria, DPH, a consultant to the Massachusetts Department of Public Health in Boston, who was not involved with the study, said the work will be particularly helpful for primary care physicians, giving them confidence to not recommend PEP when infection is statistically highly unlikely and thereby to reduce unnecessary and costly measures.

“Concern about rabies is often based on a very unlikely scenario,” Dr. DeMaria said. He gave the example of people coming into primary care worried that they might have been exposed after comforting their dog who had been bitten in a fight with a wild animal.

“Has that ever happened in the history of the human species? Not that we know of,” he said.

Many people also think dogs and other domestic animals are a likely source of rabies, which is not the case in the United States, Dr. DeMaria said.

“In most cases, it is exposure to a raccoon, a skunk, or a bat,” he said. “Most calls are for potential bat exposure, especially in the summer when young bats are flying around and are not very savvy about avoiding humans.”

The authors note the difference between the animals likely to bite and the species that carry RABV: “The most common mammals involved in bite events in the U.S. are dogs, cats, and small rodents. These species, when healthy and provoked into biting, represent some of the lowest risk exposures evaluated in this model.”

The canine rabies variant virus was eliminated in the United States in 2004.

The study authors note that their model should not be used in other countries because “most rabies deaths globally are caused by domestic dogs.”

Health department consultation can reduce inappropriate treatment

Dr. DeMaria said the paper may also convince physicians to consult with their health department for a final recommendation.

The authors note that a 2020 study in Cook County, Ill., found patients who received PEP were about 90% less likely to receive inappropriate treatment if their clinician had consulted with a health department.

“Anything that puts the risk in a context, like this paper does, is helpful,” he said.

Most physicians in the United States will never see a patient with rabies, the authors write, but animal bites are common – resulting in hundreds of thousands of primary care and emergency department visits each year when physicians must decide whether to administer PEP.

The study authors and Dr. DeMaria report no relevant financial relationships.

Researchers using a modeling study of rabies in the United States have quantified the risk of death and exposure and estimated a threshold to help health care providers decide when postexposure prophylaxis (PEP) is appropriate.

© astridb05/Fotolia.com

The model, reported in JAMA Network Open, could help clinicians, particularly those in primary care settings, to more rationally prescribe PEP to people concerned about a potential exposure to the rabies virus (RABV). In the United States, rabies PEP often is given without a comprehensive assessment that considers regional factors as well as species, nature of an attack, and the health and vaccination status of the animal.

Providers err on the side of caution, as rabies infection has a fatality rate near 100%. When exposures are low-risk, however, patients can rack up substantial out-of-pocket expenses or experience unnecessary adverse effects from the series of shots. Those can include injection site reactions, hypersensitivity reactions, and neurological complications.

The authors write that an estimated 55,000 people per year in the United States were treated for potential exposure to RABV in 2017 and 2018, at an estimated cost of more than $3,800 per person treated.
 

Researchers calculate risk threshold

The researchers, led by Kelly Charniga, PhD, MPH, an infectious disease epidemiologist with the U.S. Centers for Disease Control and Prevention in Atlanta, calculated positivity rates using more than 900,000 animal samples tested for RABV between 2011 and 2020. Other parameters were estimated from surveillance data and the literature and probabilities were estimated using Bayes’ rule.

A convenience sample of state public health officials in all states (excluding Hawaii) plus Washington and Puerto Rico was used to help determine a risk threshold for recommending PEP. Respondents were asked whether they would recommend PEP given 24 standardized exposure scenarios while accounting for local rabies epidemiology.

Their model establishes a risk threshold of 0.0004 for PEP administration, which represents the probability that an animal would test positive for RABV given that a person was exposed, and the probability that a person would die from rabies after exposure to a suspect rabid animal and no PEP. PEP should not be recommended with any value lower than that cutoff.

Alfred DeMaria, DPH, a consultant to the Massachusetts Department of Public Health in Boston, who was not involved with the study, said the work will be particularly helpful for primary care physicians, giving them confidence to not recommend PEP when infection is statistically highly unlikely and thereby to reduce unnecessary and costly measures.

“Concern about rabies is often based on a very unlikely scenario,” Dr. DeMaria said. He gave the example of people coming into primary care worried that they might have been exposed after comforting their dog who had been bitten in a fight with a wild animal.

“Has that ever happened in the history of the human species? Not that we know of,” he said.

Many people also think dogs and other domestic animals are a likely source of rabies, which is not the case in the United States, Dr. DeMaria said.

“In most cases, it is exposure to a raccoon, a skunk, or a bat,” he said. “Most calls are for potential bat exposure, especially in the summer when young bats are flying around and are not very savvy about avoiding humans.”

The authors note the difference between the animals likely to bite and the species that carry RABV: “The most common mammals involved in bite events in the U.S. are dogs, cats, and small rodents. These species, when healthy and provoked into biting, represent some of the lowest risk exposures evaluated in this model.”

The canine rabies variant virus was eliminated in the United States in 2004.

The study authors note that their model should not be used in other countries because “most rabies deaths globally are caused by domestic dogs.”

Health department consultation can reduce inappropriate treatment

Dr. DeMaria said the paper may also convince physicians to consult with their health department for a final recommendation.

The authors note that a 2020 study in Cook County, Ill., found patients who received PEP were about 90% less likely to receive inappropriate treatment if their clinician had consulted with a health department.

“Anything that puts the risk in a context, like this paper does, is helpful,” he said.

Most physicians in the United States will never see a patient with rabies, the authors write, but animal bites are common – resulting in hundreds of thousands of primary care and emergency department visits each year when physicians must decide whether to administer PEP.

The study authors and Dr. DeMaria report no relevant financial relationships.

Researchers using a modeling study of rabies in the United States have quantified the risk of death and exposure and estimated a threshold to help health care providers decide when postexposure prophylaxis (PEP) is appropriate.

© astridb05/Fotolia.com

The model, reported in JAMA Network Open, could help clinicians, particularly those in primary care settings, to more rationally prescribe PEP to people concerned about a potential exposure to the rabies virus (RABV). In the United States, rabies PEP often is given without a comprehensive assessment that considers regional factors as well as species, nature of an attack, and the health and vaccination status of the animal.

Providers err on the side of caution, as rabies infection has a fatality rate near 100%. When exposures are low-risk, however, patients can rack up substantial out-of-pocket expenses or experience unnecessary adverse effects from the series of shots. Those can include injection site reactions, hypersensitivity reactions, and neurological complications.

The authors write that an estimated 55,000 people per year in the United States were treated for potential exposure to RABV in 2017 and 2018, at an estimated cost of more than $3,800 per person treated.
 

Researchers calculate risk threshold

The researchers, led by Kelly Charniga, PhD, MPH, an infectious disease epidemiologist with the U.S. Centers for Disease Control and Prevention in Atlanta, calculated positivity rates using more than 900,000 animal samples tested for RABV between 2011 and 2020. Other parameters were estimated from surveillance data and the literature and probabilities were estimated using Bayes’ rule.

A convenience sample of state public health officials in all states (excluding Hawaii) plus Washington and Puerto Rico was used to help determine a risk threshold for recommending PEP. Respondents were asked whether they would recommend PEP given 24 standardized exposure scenarios while accounting for local rabies epidemiology.

Their model establishes a risk threshold of 0.0004 for PEP administration, which represents the probability that an animal would test positive for RABV given that a person was exposed, and the probability that a person would die from rabies after exposure to a suspect rabid animal and no PEP. PEP should not be recommended with any value lower than that cutoff.

Alfred DeMaria, DPH, a consultant to the Massachusetts Department of Public Health in Boston, who was not involved with the study, said the work will be particularly helpful for primary care physicians, giving them confidence to not recommend PEP when infection is statistically highly unlikely and thereby to reduce unnecessary and costly measures.

“Concern about rabies is often based on a very unlikely scenario,” Dr. DeMaria said. He gave the example of people coming into primary care worried that they might have been exposed after comforting their dog who had been bitten in a fight with a wild animal.

“Has that ever happened in the history of the human species? Not that we know of,” he said.

Many people also think dogs and other domestic animals are a likely source of rabies, which is not the case in the United States, Dr. DeMaria said.

“In most cases, it is exposure to a raccoon, a skunk, or a bat,” he said. “Most calls are for potential bat exposure, especially in the summer when young bats are flying around and are not very savvy about avoiding humans.”

The authors note the difference between the animals likely to bite and the species that carry RABV: “The most common mammals involved in bite events in the U.S. are dogs, cats, and small rodents. These species, when healthy and provoked into biting, represent some of the lowest risk exposures evaluated in this model.”

The canine rabies variant virus was eliminated in the United States in 2004.

The study authors note that their model should not be used in other countries because “most rabies deaths globally are caused by domestic dogs.”

Health department consultation can reduce inappropriate treatment

Dr. DeMaria said the paper may also convince physicians to consult with their health department for a final recommendation.

The authors note that a 2020 study in Cook County, Ill., found patients who received PEP were about 90% less likely to receive inappropriate treatment if their clinician had consulted with a health department.

“Anything that puts the risk in a context, like this paper does, is helpful,” he said.

Most physicians in the United States will never see a patient with rabies, the authors write, but animal bites are common – resulting in hundreds of thousands of primary care and emergency department visits each year when physicians must decide whether to administer PEP.

The study authors and Dr. DeMaria report no relevant financial relationships.