Is Lyme disease sexually transmitted?

Although the report by M.J. Middelveen et al. (1), suggests that Lyme disease may be a sexually transmitted infection, it relies solely on the detection ofBorrelia in the semen and vaginal secretionsof a small number of people; there is no evidence to date indicating that borreliosis can be transmitted in this manner. Based on little more than these preliminary and unconfirmed observations, Stricker and Middleveen (2), nevertheless, have proposed that their results “might create a paradigm shift that would transform Lyme disease from a tick-borne illness into a sexually transmitted infection”. This is nonsense to say the least

Because Borreliaburgdorferihas been reported to elicit a generalized disseminated infection in several well-characterized animal models of borreliosis, it is not surprising that sprirochetes have been isolated from the spleen, eyes, kidneys, liver, tested and the brain of infected animals, several days after infection (3, 4). However, the concept that borreliosis can be transmitted by direct contact or sexually of was refuted several years ago by the well-designed, peer-reviewed published studies of Moody and Barthold (5), as well as Woodrum and Oliver (6), internationally known experts on Lyme disease.These investigatorsused well-characterized animal models of borreliosis in which infection is much more disseminated and profound than it is in humans. It should be noted that, in the United States, Lyme borreliosis has historically been defined as atick borne infection caused by Borreliaburgdorferisensulato(7).

To determine if borreliosis can be transmittedby direct contact, Moody and Barthold (5) housed three-day-old (or three-week-old) Lewis rats, deliberately infected with B.burgdorferi, with normal, uninfected ratsfor 30 days. As expected, all deliberatelyinfected rats continued to be actively infected, 30 days later; however, none of the uninfected rats acquired infection after 30 days of intimate direct contact withtheir infected cage mates.

In other experiments, Moodyand Barthold (5) were unable to demonstrate venereal transmission of borreliosisfrom seven infected females-or sixinfected males -to uninfected rats of the oppositesex. In the work of Woodrum and Oliver (6), six female Syrianhamsters infected with B.burgdorferiwere mated with six uninfected males; conversely, three infected males were mated with six uninfected females. None of the uninfected hamsters became infected after matingwith an infected partnerof the opposite sex, indicatingthat borreliosisis not sexually transmitted.Obviously, the mere presence of borrelia in genital tissues does not mean that infection can be transmitted sexually. It should be noted that epidemiological data do not support the view that Lyme disease is sexually transmitted. Extensive data collected by the CDC indicate that 96% of all reported cases of Lyme disease occur in 14 States ( ), a pattern that is strikingly different from that for sexually transmitted diseases. Woodrum and Oliver (6) likewisefailed to demonstratecontact transmission of B. burgdorferibetween infected female-or male-hamsters and uninfected hamsters of the opposite sex. Itwas not possible to transmit borreliosisto uninfected hamsters with urine or feces from infected hamsters.

Sadly, the observations of Middleveen et al.(1) have already generated an inordinate amount of fear and anxiety within the lay community due to sensationalized reports of their unconfirmed findings by an uncritical -and often naïve -press. This has already caused much harm, as evidenced by the fact that I have received numerous inquiries from distraught individuals, wondering if they now should even consider marrying their previously diagnosed and treated spouse-to-be for fear of getting Lyme disease and/orrisking the possibility of giving birth to an infected or congenitally deformed child.

To examine the issue of in uterotransmission of boreliosis, Moody and Barthold (5) inoculated pregnant female Lewis rats with viable B. burgdorferi, at four days of gestation. All of the inoculated pregnant females became seropositive as expected, and B. burgdorfericould be cultured from their spleens at 20 days of gestation; however, their placentas and fetuses were culture negative, indicting the lack of
in uterotransmission. Moody and Barthold (5)used two different experimental protocols to determine if transplacental transmission of B. burgdorferioccurs. One protocol involved six non-pregnant infected females that were subsequently mated and became pregnant. Three of the females were allowed to carry to full term, whereas the remaining three were sacrificed just prior to parturition. All offspring
and offspring-to-be were found to be culture negative for B. burgdorferi, as well as seronegative for antibody specific for B. burgdorferi, indicating that transplacental transmission of infection does not occur. In the second protocol, six females were infected viatick bite after becoming pregnant, and were allowed to carry their fetuses to birth; all were negative for infection. The resultsof these studies likewise failed to provide evidence for the transplacental transmission of naturally acquired borreliosis.

Other investigators examined the possibility of congenital birth defects in humanswith Lyme diseaseby doing a rather large comparative study involving 5,000 infants, half from an area in which Lyme disease was endemic and half as controls froman area without Lyme disease (8). They found no significant differences in the overall incidence of congenital malformations between the two groups.

In another study, involving 1,500 subjects including controls,no increased risk of giving birth to a child with a congenital heart defect wasnotedin women who had either been bitten by a tick or had been treated for Lyme disease during or before pregnancy (9).Finally, an extensive analysisof the world literature revealed“that an adverse outcome due to maternal infection with B. burgdorferiat any point during pregnancy in humans is at most extremely rare” (10).

Phillip J. Baker, Ph.D.
Executive Director
American Lyme Disease Foundation
P.O. Box 466
Lyme, CT 06371


1. Middleveen, MJ, Burke, J, Mayne, PJ, and Stricker, RB. F1000Research 27 Apr 2015,(doi 10.126881/f1000research.5778.33:309

2. Stricker, RB, and Middleveen, 1MJ. Sexual transmission of Lyme disease: challenging the tickborne disease paradigm. Expert. Rev. Anti. Infect. Ther. 2015; 11:1303-1306.

3. Johnson,RC, Marek, N, and Kodner, C. Infection of Syrian hamsters with Lyme disease spirochetes. J. Clin. Microbiol. 1984; 20:1099-1101.

4. Barthold, SW, Persing, DH, Armstrong, AL, and Peeples, RA. Kinetics of Boreliaburgdorferidissemination and evaluation of disease after intradermal inoculation of mice. Amer. J. Pathol 1991; 139:263-273.

5. Moody, KD and Barthold, SW. Relative infectivity of Borreliaburgdorferiin Lewis rats by various routes of inoculation. Amer. J. Trop. Med. Hyg. 1991;44:135-139.

6. Woodrum, JE and Oliver, JH Jr. Investigation of venereal, transplacental, and contact transmission of the Lyme disease spirochete, Borreliaburgdorferi,in Syrian hamsters. J. Parasitol. 1999;85:426-430.

7. Wormser, GP and O’Connell, S. Treatment of infection caused by Borreliaburgdorferisensulato. Expert. Rev. Anti. Infect. Ther 2011;9:245-260.

8. Williams, CL, Strobino, B, Weinstein, A,etal Maternal Lyme disease; congenital malformations and a cord blood serosurvey in endemic and control areas. Paediatr. Perinat. Epidemiol. 1995;9:320-330.

9. Strobino, B, Abid, S, and Gewitz, M. Maternal Lyme disease and congenital heart disease: a case control study in an endemic area. Amer. J. Obstet. Gynecol 1999;180:711-716.

10. Elliot, DJ, Eppes, SC, and Klein, JD. Teratology Update: Lyme disease. Teratology 2001;64:276-286.