One of the most debated questions in the Lyme community has nothing to do with ticks. It is whether Borrelia burgdorferi, the spirochete behind Lyme disease, can pass between people through intimate contact. It is an uncomfortable question, and an honest answer has to start with a plain admission: we do not know for certain. What we can do is look at what the research actually shows, what it does not show, and why the question keeps coming up.
This post is a review of an open scientific discussion, not a medical claim. Santa Maria Health does not assert that Lyme disease is sexually transmitted. Our role is different — to help people with Lyme understand the evidence clearly and to access accurate diagnostics so that decisions are based on facts rather than fear.
The Biology of Spirochetes
The reason this question is taken seriously by anyone at all comes down to biology. Borrelia burgdorferi belongs to a family of corkscrew-shaped bacteria called spirochetes. Its best-known relative is Treponema pallidum — the organism that causes syphilis, and one of the most firmly established sexually transmitted infections in medicine.
That shared family tree is what makes the idea biologically plausible rather than absurd. Spirochetes are motile, tissue-invasive organisms capable of persisting in the body and reaching sites beyond the bloodstream. Plausibility, however, is not the same as proof. Two bacteria can share a structure and a family name and still behave completely differently inside the human body. The syphilis parallel is a reason to ask the question — not an answer to it.
What the Research Has Found
The study most often cited in this discussion is by Middelveen and colleagues, published in F1000Research in 2014. The researchers cultured genital secretions from people with Lyme disease and reported identifying Borrelia spirochetes in vaginal and seminal samples. You can read the paper directly: https://pubmed.ncbi.nlm.nih.gov/28690828/
Two things about this study matter, and honesty requires stating both. First, finding the organism in genital secretions is a genuinely interesting observation that the authors themselves argued merits further investigation. Second, the study was small, and it did not pass through the peer-review process cleanly — in its revised version, one reviewer approved it and two did not. The authors of a related 2015 review were direct about the limits of their own argument, describing sexual transmission of Lyme as speculative and calling for more study rather than declaring the matter settled.
There is also a logical gap that no honest summary should skip. Detecting bacteria in a fluid is not the same as showing that the fluid can transmit infection to another person. Animal studies designed to test that exact question — mating infected and uninfected animals — did not demonstrate venereal transmission. That is a meaningful counterweight, not a footnote.
Why the CDC Does Not Recognize It
The U.S. Centers for Disease Control and Prevention is unambiguous on this point. The CDC states there is no credible scientific evidence that Lyme disease spreads through touching, kissing, or sexual contact, and points to published animal studies that failed to support sexual transmission, as well as to features of the spirochete’s biology that the agency considers incompatible with that route. Their position is here: https://www.cdc.gov/lyme/causes/index.html
It is worth holding two ideas at once. The CDC’s position reflects the current weight of evidence, and it is the responsible default for public health guidance. At the same time, absence of proof is not the same as proof of absence — which is precisely why a handful of researchers continue to argue the question deserves rigorous study rather than dismissal. A reader does not have to pick a side to take both points seriously.
Why This Matters for Patients and Partners
For someone living with Lyme, the practical takeaway is not alarm. It is informed decision-making. The unresolved nature of this question is itself the reason to approach it calmly rather than anxiously.
What a thoughtful response looks like in practice is straightforward: partners who have unexplained, persistent symptoms consistent with Lyme deserve accurate testing rather than reassurance based on assumptions. Honest conversations within a relationship are healthier than silence built on uncertainty. And general immune resilience and reduced pathogen burden are worthwhile health goals for anyone with chronic Lyme, independent of the transmission debate. None of this depends on the sexual-transmission question being resolved one way or the other — which is exactly why it is reasonable advice today.
What Santa Maria Can Do
Santa Maria Health does not make claims about how Lyme spreads. What we do is help people get a clear picture of whether Borrelia and related infections are present, and support the body’s capacity to manage them.
On diagnostics, we work with specialized Lyme laboratories — including a regional partner lab in Tijuana — that can return results in a fraction of the turnaround time of many distant labs, alongside live blood microscopy and comprehensive infection panels. Accurate testing is the foundation of every sensible decision in this area, including any conversation a couple might want to have.
Beyond diagnostics, our integrative protocols focus on immune support, detoxification, and lowering overall pathogen load — the same goals that matter for chronic Lyme regardless of where the transmission science eventually lands. Our co-founder’s own journey through Lyme disease is part of why this work is personal here; you can read more on our Our Story page, and explore the full range of what we offer on our health programs page.
The honest bottom line: the science is unsettled, the CDC says one thing, a minority of researchers say the question is still open, and good decisions come from clear information rather than from either alarm or dismissal.