Bartonella Infection Clinical Trials and Treatments

Bartonella are gram-negative intracellular bacteria with multiple species capable of causing human disease. The most well-known transmission route is through cat scratches or bites (for Bartonella henselae), but the role of ticks as a transmission vector is an active and important area of research. Laboratory studies have demonstrated that Ixodes ricinus ticks feeding on Bartonella-spiked blood retained bacterial DNA in over a third of specimens, and Bartonella DNA has been found in approximately 3% of wild ticks across multiple surveys.

The most common symptoms of Bartonella Infection include Prolonged low-grade fever and fatigue, Swollen lymph nodes, particularly near the site of tick exposure, Bone pain and joint inflammation, Skin lesions including bacillary angiomatosis in immunocompromised patients, Neurological symptoms including headaches, cognitive difficulty, and encephalopathy, among others. Meets the European rare disease definition (affects 1 or fewer per 2,000 people). Chronic bartonellosis prevalence is difficult to estimate due to underdiagnosis. Bartonella DNA has been detected in approximately 3% of wild ticks surveyed across multiple studies.. Symptoms can range from mild to severe and may vary between individuals.

Trial Friend lists all active clinical trials for Bartonella Infection from ClinicalTrials.gov, with eligibility criteria translated into plain English. Patients can filter by trial phase and recruitment status, search by location, and use the Match Me tool to score trials against their profile. Clinical trial activity for Bartonella is limited but research funding is growing. The Steven and Alexandra Cohen Foundation awarded $4.

Yes. As of September 2026, Trial Friend lists 3 FDA-approved drugs used to treat Bartonella Infection: Vibramycin (doxycycline), first approved in 1967; Rifadin (rifampin), first approved in 1971; and Zithromax (azithromycin), first approved in 1991.

Each has its own page with what the label covers, side effects and how it is given, and the Treatments section of this page adds any further approved drugs found in FDA labeling data.

Bartonella infections are caused by intracellular bacteria with multiple pathogenic species. The most established transmission route for Bartonella henselae is through cat scratches or bites, but growing research implicates tick transmission as a vector, with laboratory studies showing Ixodes ricinus ticks retaining Bartonella DNA in over a third of specimens after feeding, and Bartonella DNA detected in approximately 3 percent of wild ticks surveyed globally. Bartonella infects vascular endothelial cells and can affect the blood vessels, liver, spleen, and nervous system. The bacteria participate in polymicrobial biofilm communities in the gut, sharing genetic material with other bacteria in a protective matrix resistant to antibiotics and immune clearance. Bartonella can disrupt the autonomic nervous system, contributing to gastroparesis, cardiac rhythm disturbances, and widespread pain. Coinfection is reported in over 28 percent of chronic Lyme patients in survey data.

Bartonella infection is not a genetic disease, but host immune genetics influence susceptibility, persistence, and severity. IRF5 gene polymorphisms (rs2004640 GT/TT genotype) are associated with hemophagocytic lymphohistiocytosis in Bartonella henselae infection. B-cell deficiency from genetic immunodeficiency conditions (X-linked agammaglobulinemia, common variable immunodeficiency) or from rituximab therapy creates high risk for persistent, uncontrolled bacteremia because antibody-mediated immunity is essential for controlling Bartonella. MTHFR variants (C677T, A1298C) affect detoxification capacity during prolonged antibiotic treatment. TLR2 and TLR4 polymorphisms influence the innate immune response to gram-negative bacteria including Bartonella and may affect whether the infection becomes chronic. Patients with known immunodeficiency should discuss these factors with their infectious disease specialist.

Eligibility for Bartonella Infection clinical trials depends on factors like age, diagnosis, treatment history, and overall health. Each trial sets its own inclusion and exclusion criteria. Trial Friend translates these requirements from medical language into plain English so patients can review them more easily. The Match Me tool can score your profile against active trials to help identify studies that may be a fit.

Participating in a Bartonella Infection clinical trial typically involves scheduled visits, medical tests, and close monitoring by a research team. Depending on the study phase, you may receive an investigational treatment, a placebo, or the current standard of care. Trials may last from a few weeks to several years. Study participation is voluntary, and you can withdraw at any time.

Bartonella clinical trial activity is currently limited, but when trials are available, they typically focus on antibiotic regimens and diagnostic approaches. Standard treatment involves prolonged courses of azithromycin, doxycycline, or rifampin, often in combination. If you are on immunosuppressive therapy, this is clinically significant for both disease course and potential trial eligibility. Trial Friend's medication conflict checker scans each trial's exclusion criteria against common Bartonella and tick-borne coinfection medications including azithromycin, doxycycline, rifampin, fluoroquinolones, and immunosuppressive agents. Because Bartonella frequently coexists with Lyme disease and babesiosis, your medication regimen for those conditions is also relevant. The checker flags the specific drug, exclusion language, and a confidence level so you can discuss with your Lyme-literate doctor.

Key questions to ask your Lyme-literate doctor (LLMD) or infectious disease specialist about Bartonella include: Has Bartonella been ruled out with BAPGM enrichment culture and PCR testing, not just standard serology which misses many cases? Could my neurological symptoms, autonomic dysfunction, or gastroparesis be related to Bartonella's tropism for vascular and nervous tissue? Have I been tested for Lyme and Babesia coinfection since I may have acquired multiple infections from a single tick bite? If I have MTHFR variants, are my detoxification pathways being supported during prolonged antibiotic treatment? Should we consider biofilm disruption strategies (proteolytic enzymes on empty stomach) alongside standard antibiotics? Are my symptoms consistent with EBV or CMV reactivation on top of the bacterial infection? Do I have any B-cell or humoral immune deficiency that could explain persistent bacteremia? Is the Bartonella Research Consortium at NC State, Duke, or Tulane running any new treatment studies I should know about?