Brent Arehart // These are strange times that we are living in. Politicians joking about the “beer virus,” social media encouraging social distancing, polls closing in the middle of a primary, dogs being walked by drones—very strange indeed. But it might not be all bad. Self-quarantining means more time at home. More time at home means more opportunities to do what you love. And if you happen to be self-quarantining with a loved one doing what you both love… well, you get the picture. While we are all distracting ourselves with the new baby boom, it may also be edifying to review the ways in which disease can not only impact our lives, but our sex lives as well. This won’t be your average birds and the bees talk, though. Instead, we are going to talk about diseases that you probably have never thought about in the bedroom before.
But first, what makes a disease “sexual”? The terminology is not as straightforward as it may seem. STD (sexually transmitted disease) and STI (sexually transmitted infection) are most commonly encountered, among others that still appear in the literature, such as venereal disease. Yet, as Janet Byron Anderson has pointed out, there remains an underlying discrepancy between transmittedness and transmissibility. The former refers to the fact of transmission, while the latter refers to the potential for transmission. Depending on the circumstances, not every STD/STI that is transmissible will be transmitted. Moreover, some STDs/STIs such as hepatitis A are transmissible via fomites (i.e. inanimate objects capable of transferring an infectious agent), while others such as congenital herpes are transmitted at birth.
On a practical level, it makes sense to group together a handful of diseases that are most often transmitted through sexual intercourse. Yet, the process of sexual transmission is much more complicated. To give a recent example: it came to light in 2008 that Zika virus had been sexually transmitted. Subsequent research confirmed the presence of Zika virus RNA in the semen of infected men [Atkinson et al.]. The underlying culprit is viremia, the process in which a virus enters the bloodstream—whence its eventual passage into semen. Moreover, Zika is not the only virus that can end up in semen. A recent study calculates that at least twenty-seven viruses have been found in human semen, including adenovirus and Ebola. Of course, this does not mean that all viruses remain viable in semen or indefinitely transmissible, but it definitely provides some food for thought! As Heinz Feldmann, M.D, asks, “do these viral diseases then all become STIs?” Not in the traditional sense, probably, but in some sense yes—if they are sexually transmissible.
Obviously, one of the best ways to find out about transmissibility is through instances of transmittedness. Unfortunately, we do not always know the details of transmission. Take rabies for example: it has been theorized that, under the right circumstances, rabies could be sexually transmissible, though purportedly documented instances may be unreliable [Plotkin, p.11; Gongal et al., p.938]. Yet, rabies can be a sexual disease in another, even more dire way. We tend to associate rabies with symptoms such as aggression, hydrophobia, and sensitivity to light, but it can also manifest as increased libido and priapism. In several cases, an upwards of twenty or more ejaculations per day have been reported [Tian et al.]. While these symptoms are rare, comparatively speaking, they still merit consideration. Every second counts with a disease as deadly as rabies; patients cannot afford a delayed or misdiagnosis [Tian et al.].
The routine application of “sexually transmitted” to a narrower set of diseases probably won’t change any time soon. But the more we learn, the more it becomes clear that traditional sexual diseases are not the only ones transmissible through sex, nor are they the only ones that manifest sexually.
Featured Image: A dog with rabies and a detail of its skull. Line engraving by L.P. Baltard. [Cropped]. Public Domain. Wellcome Collection.
Atkinson, B., et al. “Presence and Persistence of Zika Virus RNA in Semen, United Kingdom, 2016.” Emerging Infectious Diseases 23.4 (2017): 611-615.
Gongal, G., et al. “What is the risk of rabies transmission from patients to health care staff?” Asian Biomedicine 6.6 (2012): 937-939.
Plotkin, S. “Rabies.” Clinical Infectious Diseases 30.1 (2000): 4-12.
Tian, Z., et al. “Clinical features of rabies patients with abnormal sexual behaviors as the presenting manifestations: a case report and literature review.” BMC Infectious Diseases 19 (2019), article no. 679. [open access]