Lyme Borreliosis is not Sexually Transmitted
From experience as a research scientist and an editor for various scientific journals, I appreciate the fact that abstracts presented at scientific meetings sometimes consist of rather exciting – but at the same time still very preliminary findings that are not always reproducible. Therefore, abstracts are not given the same consideration as peer-reviewed publications and cited in the bibliographies of peer-reviewed scientific papers. Consequently, one must be skeptical of their credibility, especially when they contradict the results of rigorously reviewed published research. Here, I refer specifically to the recent abstract by M.J. Middelveen et al. (1), suggesting that Lyme disease may be a sexually transmitted infection, a suggestion based solely on the unconfirmed detection of Borrelia in the semen and vaginal secretions of only three people. Based on little more than these preliminary and unconfirmed observations, Stricker and Middleveen (2) 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”.
Because Borrelia burgdorferi has been reported to elicit a generalized disseminated infection in several well-characterized animal models of borreliosis, it is not surprising that spirochetes have been isolated from the spleen, eyes, kidneys, liver, testes 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 investigators used 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 a tick-borne infection caused by Borrelia burgdorferi sensu lato(7).
To determine if borreliosis can be transmitted by direct contact, Moody and Barthold (5) housed three-day-old (or three-week-old) Lewis rats, deliberately infected with B. burgdorferi, with normal, uninfected rats for 30 days. As expected, all deliberately infected rats continued to be actively infected, 30 days later; however, none of the uninfected rats acquired infection after 30 days of intimate direct contact with their infected cage mates. In other experiments, Moody and Barthold (5) were unable to demonstrate venereal transmission of borreliosis from seven infected females -or six infected males -to uninfected rats of the opposite sex.
In the work of Woodrum and Oliver (6), six female Syrian hamsters infected with B.burgdorferi were mated with six uninfected males; conversely, three infected males were mated with six uninfected females. None of the uninfected hamsters became infected after mating with an infected partner of the opposite sex, indicating that borreliosis is 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 (http://www.cdc.gov/lyme/stats/index.html ), a pattern that is strikingly different from the nation-wide general distribution of sexually transmitted diseases (www.cdc.gov/std/default.htm ). Woodrum and Oliver (6) like wise failed to demonstrate contact transmission of B. burgdorferi between infected female-or male-hamsters and uninfected hamsters of the opposite sex. It was not possible to transmit borreliosis to 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/or risking the possibility of giving birth to an infected or congenitally deformed child.
To examine the issue of in utero transmission of borreliosis, Moody and Barthold (5) inoculated pregnant female Lewis rats with viable B. burgdorferi, at four days of gestation. All inoculated pregnant females became seropositive as expected, and B. burgdorferi could be cultured from their spleens at 20 days of gestation; however, their placentas and fetuses were culture negative, indicting the lack of in utero transmission. Moody and Barthold (5) used two different experimental protocols to determine if transplacental transmission of B. burgdorferi occurs. 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 via tick bite after becoming pregnant and were allowed to carry their fetuses to birth; all were negative for infection. The results of these studies like wise failed to provide evidence for the transplacental transmission of naturally acquired borreliosis.
Other investigators examined the possibility of congenital birth defects in humans with Lyme disease by doing a rather large comparative study involving 5,000 infants, half from an area in which Lyme disease was endemic and half as controls from an 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 was noted in women who had either been bitten by a tick or had been treated for Lyme disease during or before pregnancy (9). Finally, an extensive analysis of the world literature revealed “that an adverse outcome due to maternal infection with B. burgdorferi at any point during pregnancy in humans is at most extremely rare” (10).
Phillip J. Baker, Ph.D.
American Lyme Disease Foundation
1. Middleveen, MJ, Bandoski, C, Burke, J, Sapi, E, Mayne, PJ, and Stricker, RB. Isolation and detection of Borrelia burgdorferi from human vaginal and seminal secretions. Abstract #460, Western Regional Meeting of the American Federation for Medical research (January 2014).
2. Stricker, RB, and Middleveen, MJ. 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 Borelia burgdorferi dissemination 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 Borrelia burgdorferi in 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, Borrelia burgdorferi,in Syrian hamsters.
J.Parasitol. 1999; 85: 426-430.
7. Wormser, GP and O’Connell, S. Treatment of infection caused by Borrelia burgdorferi sensulato. Expert. Rev. Anti. Infect. Ther. 9: 245-260, 2011.
8. Williams, CL, Strobino, B, Weinstein, A, et al. Maternal Lyme disease; congenital malformations and a cord blood serosurvey in endemic and control areas. Paediatr. Perinat. Epidemiol. 9: 320-330, 1995.
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. 180: 711-716, 1999.
10. Elliot, DJ, Eppes, SC, and Klein, JD. Teratology Update: Lyme disease. Teratology 64: 276286, 2001.