Chronic Lyme Illness Needs Symptom-Targeted Treatments

Medscape

10-06-2025

Lyme infection-associated chronic illness (IACI) is real, often debilitating and long-lasting, and in urgent need of research that prioritizes treatments to improve symptoms affecting patients' function and quality of life — rather than waiting for certainty about cause, the National Academy of Sciences, Engineering, and Medicine (NASEM) concluded in a new report on Lyme IACI.
An estimated tens of thousands of people in the US each year develop what the NASEM is calling Lyme IACI, often presenting with chronic fatigue, recurring pain, cognitive dysfunction and/or sleep disturbances despite receiving recommended antibiotic treatment for Lyme disease, the Academy's Committee on the Evidence Base for Lyme IACI Treatment wrote. These symptoms are distinct from known complications of Lyme disease such as arthritis and carditis.
'Testing interventions that act on symptoms as opposed to [waiting for an understanding of] pathogenic mechanisms is the most efficient approach to identifying treatments [that can] help patients living with Lyme IACI find relief,' NASEM Committee Chair Kent Kester, MD, said in a webinar held last month about the report.
Mechanism studies should be conducted in parallel to guide future treatment studies, said Kester, an internist and infectious disease specialist who is currently the executive director of Vaccine Research and Development at the Coalition for Epidemic Preparedness Innovations.
The report also emphasizes the 'unrealized opportunity' for the sharing of knowledge about other IACIes — such as long COVID and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) — to better understand potentially common mechanistic pathways and treatments.
It calls for the US Department of Health and Human Services to develop an integrated strategic plan for IACI research broadly, as well as a standardized research definition for Lyme IACI, and it recommends that a Lyme IACI research data coordinating center be developed to improve research efforts on Lyme IACI that currently are 'decentralized and uncoordinated.'
'This vision [for research] is terrific because basically it's saying that we need to view Lyme disease similarly to the way we view other illnesses that have chronic persistent symptoms…and that we can learn a lot from sharing knowledge…The time is now,' said Brian A. Fallon, MD, MPH, professor of clinical psychiatry and director of the 17-year-old Lyme and Tick-Borne Diseases Research Center at the Columbia University Irving Medical Center, New York City, who was not on the NASEM Lyme IACI committee.
'Clinicians have been struggling for a long time because they see patients with persistent symptoms and sometimes the Lyme disease has been really well diagnosed, and sometimes it is likely or possibly Lyme disease, but they're not really sure,' he said in an interview, 'and they're not sure how to treat these patients.'
A scoping review of the literature conducted for the NASEM committee covered treatment, pathogenesis, and diagnosis of Lyme IACI, and it documented both the sparsity of randomized controlled treatment trials over the past 20 years and the poor understanding of mechanisms. Regarding diagnostic methods, research 'remains in the early stages of discovery,' the report said. 'No single candidate [test or method] stands out.'
The broad recognition of long COVID has galvanized acceptance of Lyme IACI and of chronic disease states with potential infectious triggers, the committee wrote. However, in a statement about the report, physician leaders of the International Lyme and Associated Diseases Society (ILADS) expressed ongoing concern.
The National Academies report 'rightly identifies that many people with Lyme IACI experience…symptoms strikingly similar to those found in long COVID and ME/CFS,' their statement said. 'Yet unlike these conditions, where progress toward treatment development is accelerating, patients with Lyme IACI still face stigma, dismissal, and inconsistent care.'
ILADS is a nonprofit membership organization representing physicians, scientists, and other healthcare professionals that focuses on Lyme disease and other vector-borne illnesses.
The 'State of Evidence' on Treatment
Of 85 published peer-reviewed articles identified in the scoping review and published from 1988 to 2024, 19 evaluated treatments, and only six of these were randomized trials.
Five of the six trials — all randomized controlled trials (RCTs) reported between 2001 and 2008 — evaluated extended courses of antibiotics (up to 3 months) and did not demonstrate sustained benefit in primary outcome measures. One study did not report safety monitoring, and the other five reported adverse effects, the report said.
'The lack of demonstrated effectiveness of various extended antibiotic regimens in these randomized trials suggests that pathogen persistence is not a primary driver of Lyme IACI,' the report said. 'However, the current evidence is insufficient to rule out the possibility that bacterial persistence might occur in a subset of patients living with Lyme IACI.'
The role of antibiotic treatment and the question of persistence of Borrelia burgdorferi have been among the most controversial topics in what the NASEM calls Lyme IACI, with treatment guidelines issued by the Infectious Diseases Society of America (IDSA) in 2006 and 2020 and ILADS in 2014 taking different stances and offering differing recommendations.
Asked about the NASEM report, Elizabeth L. Maloney, MD, education director of VectorWise CME, said 'it's important that [the NASEM] kept the door open to persistent infection' as a potential mechanism for further research.
(VectorWise CME, which maintains accreditation by the Accreditation Council for Continuing Medical Education [CME], provides virtual free courses on Lyme disease and other vector-borne diseases. All courses are accredited by the American Academy of Family Physicians.)
Case reports have reported detection of B burgdorferi in post-mortem human samples and in primate models that simulate delayed treatment of Lyme disease, the report noted.
Regarding the antibiotic treatment trials, Maloney said important lessons have been overlooked. One of the trials of IV ceftriaxone, for instance, reported sustained improvement in severe fatigue, which was one of its primary outcome measures. Another trial of patients with chronic cognitive impairment— this one from Fallon's group at Columbia — reported sustained improvement in secondary measures of pain and physical functioning after a 10-week course of intravenous ceftriaxone. (Patients in the Columbia study had improvement in cognition, the primary outcome, at 12 weeks — 2 weeks after treatment ended — but lost that improvement by week 24.)
'So there is some randomized controlled trial evidence — small numbers but real evidence — that ceftriaxone helped [some] patients,' said Maloney, who was a co-author of the ILADS treatment guideline.
The NASEM report gave a nod to debated issues, noting 'there remains ongoing debate over the trial designs and outcomes [of the antibiotic trials], as discussed through extensive re-analyses of the available data,' including a 2012 paper co-authored by Fallon, 'A reappraisal of the US Clinical Trials of Post-Treatment Lyme Disease Syndrome.'
The sixth RCT identified in the scoping review looked at yoga and found insufficient evidence of benefit for fatigue and pain, the report said.
With geographic differences in mind, the NASEM committee limited its scoping review to studies of Lyme IACI in the US, which it considered to be 'Lyme-associated chronic illness with otherwise unexplained symptoms that persist for at least 6 months following antibiotic treatment for either proved or presumed infection with B spp that cause Lyme disease.'
(That definition is less stringent than the IDSA's 2006 research case definition of Post-Treatment Lyme Disease Syndrome (PTLDS), which requires an initial Lyme disease diagnosis meeting the surveillance case definition used by the CDC.)
European studies are not always generalizable to the US because borrelial species associated with Lyme disease in Europe — and the clinical features of Lyme disease — can differ from those found in the US, said Maloney, who lives and has practiced in a Lyme-endemic area of Minnesota.
Maloney, a family physician, became involved in CME in 2007 after treating patients 'who didn't always present as a Lyme patient was supposed to present,' such as patients with arthritis but no history of an erythema migrans rash. 'I read the medical literature and found that things that were presented as black and white and well worked out were not,' she said, 'and had many shades of gray.'
The NASEM report only briefly discussed tick-borne coinfections, noting that little is known about how they do or do not affect the development, diagnosis, treatment, and prognosis of Lyme IACI — and that research is needed.
Evidence on Pathogenesis, Diagnosis, Incidence
The committee's scoping review identified 23 articles addressing potential mechanisms of disease, most of which were not evaluated in prospective studies. In addition to pathogen persistence — and persistence of bacterial remnants — proposed mechanisms for Lyme IACI include immune dysregulation and autoimmunity, central nervous system dysfunction, metabolomic changes, and gut dysbiosis. All are important to consider, Fallon and Maloney emphasized in interviews.
Another 27 studies covered the diagnosis of Lyme IACI. Four described direct detection methods that need to be replicated and developed into clinically useful assays; 15 described indirect detection methods using a wide range of potential biomarkers (eg, autoantibodies and other immune markers, metabolite or microbiome signatures, and CNS imaging); and the remaining eight evaluated clinical questionnaires or evaluation scales. (Only two of the eight questionnaires and scales were validated but for monitoring disease progress and not for diagnostic purposes.)
Pediatric patients have been scarce in Lyme IACI research, according to the report. Only one of the 27 papers covering diagnosis focused on the pediatric population, for instance, and only three included children along with adults.
Moving Forward
Lyme IACI is a broad and inclusive name, NASEM experts believe, that encompasses different terms used over the years to describe persistent symptoms (including chronic Lyme and persistent Lyme). The name also acknowledges the heterogeneity and different diagnostic histories of patients, they said, including those with missed and delayed diagnoses.
The development of formal consensus research definitions that 'address the different strata of the broad range of people living with Lyme IACI,' the report noted, will make it possible to more accurately determine population prevalence and to conduct impactful research. The PTLDS definition has provided standardization but is a 'subset' of Lyme IACI and excludes many individuals, Kester said in the webinar.
Thus far, limited research has suggested that 10%-20% of the approximately 476,000 patients who contract Lyme disease each year develop persistent symptoms after standard antibiotic treatment, the NASEM report said.
In addition to its call for consensus definitions, the NASEM report called on the National Institutes of Health (NIH) and CDC to define standard tools and metrics — including patient-focused outcome measures — and said that patient registries and biobanks are valuable and have been underutilized thus far. Clinical studies, it emphasized, should be 'well-designed, randomized trials with appropriate control groups.'
Maloney said possible reliance on RCTs is concerning, considering the heterogeneity of the Lyme IACI population and the need for subgroup analyses. 'I worry that [researchers] will not be able to amass the number of patients necessary, even with an expanded definition,' she said in the interview, adding that evidence-based medicine encompasses more than RCTs.
She also worries that 'with NIH funding being slashed, tick-borne disease research is not going to get the attention it needs.'
NIH funding for Lyme disease research has increased in recent years, but according to a per-patient funding analysis by the Center for Lyme Action, research on West Nile (with an estimated 2566 new diagnoses in the US in 2023) has been funded at 75 times the rate of Lyme disease. In another comparison, the $50 million granted for the study of Lyme disease in 2022 represented < 2% of the public funds invested in HIV/AIDS, according to the Center.
Understanding persistent symptomatology was part of a strategic tick-borne disease research plan that was developed by the NIH in 2019. In 2023, NIAID funded seven projects addressing persistent symptoms slated to run through 2028, with first-year funding of $3.2 million. (The NIH did not respond to a query from Medscape Medical News about the future of these and other projects relating to Lyme IACI.)
With private funding from the Steven & Alexandra Cohen Foundation, the Clinical Trials Network for Lyme and other Tick-Borne Diseases, coordinated by Fallon, has a slate of small studies underway of therapies that address potential mechanisms of Lyme IACI: tetracycline, transcranial direct current stimulation with cognitive retraining, vagus nerve stimulation, mast cell treatment, and pulse-dosed ceftriaxone).
(Network researchers have been using research classification criteria for Lyme disease that are intended to allow for more inclusive and generalizable studies. In a paper published this year, they describe their proposed research classification system, with criteria for Lyme disease at different levels of diagnostic certainty: Well-defined, probable, possible, and uncertain.)
Fallon said he is hopeful that the NASEM's recommendations can be implemented. 'Everyone's committed to reducing tick-borne illnesses, and there's a strong interest in [the Administration] in addressing chronic illness,' he said, noting 'it's not just Lyme disease — the coinfections are causing major problems.'
Practice Today
In practice, meanwhile, Fallon said he and others can help patients by utilizing approaches and therapies 'in our current armamentarium, drawing upon rheumatology, neurology, psychiatry' and other fields.
'I tend to see patients who have had chronic [neuropsychiatric] symptoms for a long time and have received quite a lot of courses of antibiotics,' he said. 'I focus on some of the treatments we know are helpful for people with neuropsychiatric symptoms. For example, there are some psychiatric medications that can help reduce arthritis pain, reduce neuropathies, help improve energy.'
Physicians trained in integrative medicine and functional medicine bring 'a broad, comprehensive approach to examination' that can be helpful in Lyme IACI, said Fallon, whose team at Columbia's Lyme and Tick-Borne Diseases Research Center includes an integrative medicine physician.
'They may look at some of the other organisms that may be complicating the course of illness, for instance. They may look for other causes of persistent symptoms such as endocrine problems or mold problems…that can complicate recovery,' he said. 'And they frequently use herbals, which can be helpful.'
In its statement, ILADS urged adoption of 'a dual-path strategy [of investing] in long-term research while also expanding access to care based on current best practices.' This includes treatments 'with emerging or empirical evidence that have shown benefit in some patient populations and carry an acceptable risk profile when monitored responsibly.'
Many patients improve, the statement said, 'with tailored therapies, including antimicrobial, immune-modulating, and symptom-targeted treatments, especially when the treatments are guided by a clinician who listens to the patient and tracks outcomes over time.'
The NASEM committee, comprised of 14 experts from various disciplines, including one patient, heard from over 35 invited speakers representing patients, clinicians, researchers, funders and more.
Their work was sponsored by the Steven & Alexandra Cohen Foundation and was recommended by the US Department of Health and Human Services Tick-Borne Diseases Working Group (TBDWG) that was established by Congress in 2016. (Maloney was a member of this group.) The TBDWG produced three reports that addressed persistent symptomatology, among many other issues, before concluding its work in 2022.