by. Dr. Bill Rawls
Posted 3/24/17

The official word from experts is that Borrelia burgdorferi, the microbe commonly associated with Lyme disease, cannot be spread sexually. However, whole families (including small children) testing positive for the microbe would suggest otherwise.

Experts base their assumptions on the fact that Borrelia burgdorferi concentrations in semen in people known to have Lyme disease are typically quite low. In addition, trans-utero spread (across the placenta during pregnancy) has not been scientifically documented.

This is in line with traits of the microbe. Host-dependent microbes can spread from host to host through a variety of different pathways, but they typically specialize in primarily one pathway. Borrelia’s preferred pathway of spread is by way of biting insects, most commonly ticks. It has honed this pathway over millions of years.

Other corkscrew-like bacteria, however, do specialize in sexual and congenital transmission. The most well known is Treponema pallidum, the microbe that causes syphilis. It’s interesting that Lyme disease and syphilis share many common symptoms and the two microbes are actually similar in many ways — except that Treponema has been honing the sexual transmission pathway for about as long as Borrelia has been taking advantage of ticks.

The fact that the two microbes are so similar might suggest that Borrelia could transmit sexually or congenitally. Borrelia is a master opportunist; if an easy opportunity arose to spread sexually or cross through the placenta into a new host, it probably would. Using its corkscrew shape, it can bore through any tissues in the body and show up almost anywhere.

The bottom line is that sexual and congenital propagation of Borrelia is possible, but much less likely than other microbes that typically spread by sexual transmission. If it were to occur, it would probably be from an infected male passing Lyme disease to a female via semen. Passing the microbe from infected female to male partner is much less likely. An infected female who became pregnant, however, could also pass the bacterium along to the fetus through the placenta.

To reduce the possibility of transmission, men suspected of having Lyme disease should use condoms during intercourse. If pregnancy is desired, antibiotics or antimicrobial herbs should be administered to reduce concentrations of the microbes before unprotected intercourse. Ideally, attempts for pregnancy should be deferred until Lyme disease symptoms have subsided.

For a pregnancy complicated by Lyme disease, the mother should undergo antibiotic treatment, especially for acute Lyme disease — but always under a doctor’s supervision. Tetracyclines, including doxycycline, should be avoided during pregnancy. Herbal therapy can be a good option if antibiotics are not tolerated.

1. Stricker RB, Middelveen MJ. Sexual transmission of Lyme disease: challenging the tickborne disease paradigm. Expert Rev Anti Infect Ther. 2015;13(11):1303-6.
2. Hercogova J, Vanousova D. Syphilis and borreliosis during pregnancy. Dermatol Ther. 2008 May-Jun;21(3):205-9.
3. Williams C et al. Maternal Lyme disease and congenital malformations: a cord blood serosurvey in endemic and control areas. Paediatr Perinat Epidemiol. 1995 Jul;9(3):320-30.
4. Strobino B et al. Lyme disease and pregnancy outcome: a prospective study of two thousand prenatal patients. Am J Obstet Gynecol. 1993 Aug;169(2 Pt 1):367-74.