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New Study Finds Lyme Bacteria Survive a 28-day Course of Antibiotics When Treated Four Months After Infection by Tick Bite

All subjects treated with antibiotics were found to have some level of infection 7–12 months post treatment.Despite testing negative by antibody tests for Lyme disease, two of 10 subjects were still infected with Lyme bacteria in heart and bladder. Lyme bacteria which persist are still viable.

Portola Valley, California, Dec. 13, 2017—Bay Area Lyme Foundation, a leading sponsor of Lyme disease research in the US, today announced results of two papers published in the peer-reviewed journals PLOS ONE and American Journal of Pathology, that seem to support claims of lingering symptoms reported by many patients who have already received antibiotic treatment for the disease.

Based on a single, extensive study of Lyme disease designed by Tulane University researchers, the study employed multiple methods to evaluate the presence of Borrelia burgdorferi spirochetes, the bacteria that cause Lyme disease, before and after antibiotic treatment in primates.  The study also measured the antibody immune response to the bacteria both pre- and post- treatment, as this is how current diagnostics typically evaluate Lyme disease in humans.

The data show that living B. burgdorferi spirochetes were found in ticks that fed upon the primates and in multiple organs after treatment with 28 days of oral doxycycline.  The results also indicated that the immune response to the bacteria varied widely in both treated and untreated subjects.

It is apparent from these data that B. burgdorferi bacteria, which have had time to adapt to their host, have the ability to escape immune recognition, tolerate the antibiotic doxycycline and invade vital organs such as the brain and heart, said lead author Monica Embers, PhD, assistant professor of microbiology and immunology at Tulane University School of Medicine.

In this study, we were able to observe the existence of microscopic disease and low numbers of bacteria, which would be difficult to see in humans but could possibly be the cause of the variable and nonspecific symptoms that are characteristic of post-treatment Lyme disease syndrome. Although current antibiotic regimens may cure most patients who are treated early, if the infection is allowed to progress, the 28-day treatment may be insufficient, based on these findings, Embers said.

The findings also demonstrated:

  • All subjects treated with antibiotics were found to have some level of infection 712 months post treatment.
  • Despite testing negative by antibody tests for Lyme disease, two of 10 subjects were still infected with Lyme bacteria in heart and bladder.
  • Lyme bacteria which persist are still viable.

To better elucidate previous animal studies demonstrating that some B. burgdorferi bacteria survive antibiotics, the study explored Lyme disease infection in rhesus macaque primates treated with antibiotics and a control group who were also infected but not treated. This species has been shown to demonstrate a progression of Lyme disease most similar to humans, particularly related to erythema migrans, carditis, arthritis, and neuropathy of the peripheral and central nervous systems.

Clearly, some medical practices governing diagnosis and treatment of Lyme disease should be reconsidered in light of this study. This study shows that we must reevaluate the current paradigm of antibody response tests for diagnosis and move away from the one size fits all approach to Lyme treatment, said Wendy Adams, Research Grant Director, Bay Area Lyme Foundation. Every day, patients with Lyme disease are told their symptoms cannot be caused by Lyme, because they test negative on antibody tests or because they have received a single course of antibiotics. More research and funding are imperative.

In the study, ticks carrying B. burgdorferi spirochetes fed on ten primates. Four months post infection, half of the primates (five) received the antibiotic doxycycline orally for 28 days at a proportional dose to that used in human treatment.  Five subjects were treated with placebo and all ten were evaluated by more than five different diagnostic methods to characterize any remaining infection. The researchers used several important techniques, including xenodiagnoses, to determine if the spirochete bacteria persisted.

The results show:

  • Few subjects displayed a rash. Although all subjects were infected, only one of the 10 displayed a rash with central clearing, the classical bulls-eye rash. The subject that developed this rash, interestingly, never mounted an immune response to five borrelia antigens throughout the study period, prior to and following treatment.
  • Organs may be infected even if antibody tests are negative. One subject which tested negative for B. burgdorferi by skin biopsy cultures, PCR and in vivo cultures, was found to have B. burgdorferi infecting the heart. Another untreated subject, who was ultimately shown to have residual Lyme bacteria in the bladder, showed a decrease in immune response over the course of infection, with a negative xenodiagnosis test in the late stage, which would signal that the animal self-cured.
  • Intact spirochetes were found in three of five treated and four of five untreated subjects based on xenodiagnosis results 12 months after the tick bite.
  • Immune responses to B. burgdorferi varied greatly post-treatment, with one subjects antibody levels dropping to pre-bite levels for three antigens while another subject experienced elevated antibodies for the same antigens throughout the study period. This is significant because it demonstrates that subjects infected with the same strain of B. burgdorferi may have different immune responses to the same antigen. And, because humans, like primates, are genetically diverse, it underscores that testing antibody responses may be inherently unreliable as a singular diagnostic modality for Lyme disease.
  • Widespread and variable microscopic disease was observed in all infected subjects, despite antibiotic treatment.  Compared to uninfected subjects of the same age, infected subjects in this study (treated and untreated) demonstrated Inflammation in and around the heart, in skeletal muscles, joints, and the protective sheath that covers the brain, and near peripheral nerves.
  • Rare, but intact B. burgdorferi spirochetes were found in the tissues of both the treated and untreated subjects. In two subjects treated with doxycycline, multiple Lyme bacteria were observed in the brain tissue. Others organs in which the spirochetes were observed included the heart, joints, bladder, skeletal muscle and adjacent to peripheral nerves.

About Lyme disease
One of the most common infectious diseases in the country, Lyme disease is a potentially disabling infection caused by bacteria transmitted through the bite of an infected tick to people and pets. If caught early, most cases of Lyme disease can be effectively treated, but it is commonly misdiagnosed due to lack of awareness and unreliable diagnostic tests. There are about 329,000 new cases of Lyme disease each year, according to statistics released in 2015 by the CDC. As a result of the difficulty in diagnosing and treating Lyme disease, as many as one million Americans may be suffering from the impact of its debilitating long-term symptoms and complications, according to Bay Area Lyme Foundation estimates.

About Bay Area Lyme Foundation
Bay Area Lyme Foundation, a national organization committed to making Lyme disease easy to diagnose and simple to cure, is the leading public foundation sponsor of innovative Lyme disease research in the US. A 501c3 non-profit organization based in Silicon Valley, Bay Area Lyme collaborates with world-class scientists and institutions to accelerate medical breakthroughs for Lyme disease. It is also dedicated to providing reliable, fact-based information so that prevention and the importance of early treatment are common knowledge. A pivotal donation from The LaureL STEM Fund covers all overhead costs and allows for 100% of all donor contributions to Bay Area Lyme Foundation to go directly to research and prevention programs. For more information about Lyme disease or to get involved, visit or call us at 650-530-2439.

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Tara DiMilia
Phone: 908-884-7024

4 Comments on “New Study Finds Lyme Bacteria Survive a 28-day Course of Antibiotics When Treated Four Months After Infection by Tick Bite

  1. Thanks for your work with Lyme disease. I was first tested in 2003 because I had a circular rash on my leg. The result was negative for Lyme. In 2012, I had another rash on my leg and this time the result was an 8 on the Western Blot test for Lyme AB. I took doxy for 4 days and couldn’t tolerate the nausea so I took amoxycycline. In 2014, 2015, 2016, 2017, the test result was about .5. My doctors tell me that I will always have this in my system, but I can’t blame my symptoms of fatigue, joint pain on Lyme. Please explain.

    1. Unfortunately, there is much controversy surrounding Lyme disease, particularly around the persistence of symptoms post-treatment. Typically when caught and treated early, Lyme disease can be eradicated successfully with an appropriate course of antibiotics. However, some patients continue to experience symptoms even after treatment (estimates range up to 20% of patients) and symptoms can linger for months or even years. This condition is typically referred to as Post-Treatment Lyme Disease (PTLD).

      Some doctors will advocate continued antibiotics for PTLD, however, others cite concerns about the safety of long-term antibiotic therapy and argue that there is no definitive evidence that the persistence of the symptoms is due to residual bacteria (a situation complicated, in part, due to the inadequacy of current (indirect) diagnostic tools which measure the body’s response to the pathogen, rather than the pathogen itself). There is also no good data that says continued positive tests are just a result of previous infection and doctors can not assure whether it is a residual or a new infection anyway.

      In short, you may wish to consult a physician familiar with Lyme disease for more counsel. You may wish to refer to the International Lyme and Associated Diseases Society (ILADS) physician directory for referrals in your area. Best wishes.

  2. My daughter has been disabled by Lyme for several years. Her former employer’s disability carrier, UNUM, has stopped her benefits. The mental, physical and financial burdens have been horrific. She lives in VT. Do you know of any class action lawsuits she might join, especially in light of these new findings?

    Thank you for all you do. I will become a donor shortly.

    A friend of mine has a step-grandson whose blood was treated by dialysis and purified under a study the grandson says was at MGH Boston and “cured of Lyme.” I inquired and could not find the study at MGH. Supposedly Stanford was involved. Do you know anything about this study? Are you involved?

    1. Thanks for your comment. We are so sorry that your daughter and family have been hit by Lyme disease. We know how difficult it is in so many ways – financial, emotional, physical.

      There is currently a federal antitrust lawsuit against the large insurers that was filed in November 2017 and is still pending. You can find out more about it here. There are also some efforts on facebook trying to pull together community members interested in pursuing class-action but it is not an area of focus for Bay Area Lyme Foundation, whose primary mission is to support new scientific research for the diagnosis, treatment, and cure of Lyme disease.

      Regarding the treatment, there is no clinical trial for Lyme at MGH using the method you describe (which sounds like plasmapheresis) that we are aware of and this approach would probably not be advisable as Borrelia typically avoid the blood stream where there is too much oxygen for them. Your friend may be talking about intravenous immunoglobulin (IVIG) infusions, which are sometimes used by doctors specializing in tick-borne diseases (TBD). The method may be listed for some other indication — for autoimmune disease, for example.

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