Lyme disease is primarily transmitted by ticks; that much most people know. The link between the words ‘Lyme’ and ‘ticks’ is cemented in the public consciousness, so much so that in 2018, many will instinctively conjure images of ticks when they hear or read something concerning Lyme disease. This is certainly progress. The enigmatic disease was only discovered a mere 43 years ago, although it has been around for centuries. Since its discovery in the town of Old Lyme, Connecticut, the disease has had a hard time being taken seriously, or at least being considered as the debilitating threat it undoubtedly is. Now that Lyme is finally becoming more visible in the mainstream medical community, patients and doctors alike are looking at ways it can be transmitted. One of the areas up for discussion is the possibility of sexual transmission.
Many severe and extreme conditions can be transmitted sexually, and everyone is aware of the dangers of prominent STDs like AIDS, HIV, syphilis, gonorrhoea and herpes. But could Lyme disease also join the line-up of threats? It was previously thought that any type of human-to-human Lyme transmission was impossible, and only specific types of tick could spread the disease. Borrelia burgdorferi is the bacteria responsible for causing Lyme; it’s carried by deer ticks in North America, and sheep ticks in Europe. It is estimated that as many as one in three ticks are contaminated with Borrelia, making the likelihood of catching Lyme in tick-populated areas quite high. Many people dismiss Lyme disease as they believe it’s easy to tell if you’ve been bitten by a tick or not. However, it is not altogether straightforward. Ticks will often seek out sheltered or hard-to-reach places on the human body before biting, and their saliva is laced with a paralytic agent that further minimises the risk of detection.
The appearance of a distinctive bullseye rash is one of the most concrete indicators of Lyme disease, although it can be quite hard to spot, and never appears in the first place in a minority of cases. This rash is accompanied by flu-like symptoms as the disease spreads in its acute stage. When these symptoms subside, the bacteria settle into the body, and the condition mutates into its chronic stage, which is notoriously hard to both diagnose and treat, and remains a point of contention between Lyme experts and other medical professionals. If the offending bacteria remains in a person’s system for many years, then it’s logical to assume that they can potentially transmit Lyme disease to their sexual partner(s) at any point during the prolonged infection. Therefore, it’s crucial to know if and how this type of transmission is possible.
According to the CDC (the Centres of Disease Control and Prevention), the case is crystal clear: their website officially states that ‘there is no credible scientific evidence that Lyme disease is spread through sexual contact’, going so far as to say that ‘the biology of the Lyme disease spirochete is not compatible with this route of exposure’. However, the CDC hasn’t got a great track history of Lyme expertise. Their position on the chronic form of Lyme is still a grey area at best, and their website also states that, in relation to the transmission of Lyme disease from mother to child during pregnancy, ‘no negative effects on the foetus have been found’. In fact, the transmission of Lyme during pregnancy is well-documented by Lyme experts and researchers, and although it’s a rare scenario, it is still possible.
So how do the experts see it? Dr. Carsten Nicolaus, head of Lyme specialists BCA-clinic in Augsburg, thinks that the question is not easily answered, and although it’s a probability, the risk seems very low. He cites a study conducted by Marianne Middelveen and Dr. Ray Stricker in 2014, which confirmed the presence of Borrelia burgdorferi in the genital secretions of Lyme-positive heterosexual couples. In one case, a couple was found to secrete an identical strain of Lyme spirochete in their separate samples, strongly indicating that the bacteria can be transmitted through unprotected sex. However, the study conducted is far too small to be of any diagnostic use; although the findings are interesting and alarming, more research and studies need be conducted to produce a concrete answer.
In theory, certainly, sexual transmission of Lyme disease is possible. The corkscrew-shaped Lyme spirochete shares many traits with Treponema pallidum, the microbe that causes syphilis. The latter is well-versed in the sexual transmission pathway, and has honed the method to near perfection. Borrelia has repeatedly been shown to be both opportunistic and insidious in the way it infects and survives in its host; it follows that if the opportunity for a new method of infection arose, it would almost certainly take it. As Lyme disease becomes more visible all over the world, it is important to remember that we know startlingly little about it, in comparison to other disorders. As such, it is crucial that meticulous study and tests continue, so we can rule out certain methods of transmission, or devise new ways to fight them.