SALT LAKE CITY — The medical community is still working around the clock to figure out all the ways COVID-19 can be spread from person to person. This nasty coronavirus is super contagious, but according to a new study we all have one less transmission avenue to worry about. Researchers from the University of Utah Health say it is unlikely that the coronavirus can be spread via sperm.
The study’s authors took part in an international project that examined a group of Chinese men who had recently tested positive for COVID-19. They found virtually no evidence that the coronavirus invades the semen or testes of infected men.
Researchers caution that their work was not comprehensive enough to definitively rule out the possibility of sex-based viral transmission.
“The fact that in this small, preliminary study that it appears the virus that causes COVID-19 doesn’t show up in the testes or semen could be an important finding,” says Dr. James M. Hotaling, a study co-author and health associate professor of urology specializing in male fertility at U of U, in a release. “If a disease like COVID-19 were sexually transmittable that would have major implications for disease prevention and could have serious consequences for a man’s long-term reproductive health.”
Other recent viruses, like Zika and Ebola, have shown the ability to spread via sex. So, an international team of Chinese and American researchers set out to determine if the coronavirus can be sexually transmitted by gathering 34 Chinese men who had been diagnosed with COVID-19 within about a month’s time. None of the men’s semen samples showed any sign of the virus.
However, those observations didn’t eliminate the possibility that the coronavirus had entered the men’s testes.
“If the virus is in the testes but not the sperm it can’t be sexually transmitted,” explains co-author Jingtao Guo, Ph.D., a postdoctoral scientist at the Huntsman Cancer Institute at the University of Utah. “But if it is in the testes, it can cause long-term damage to semen and sperm production.”
To try and determine if the coronavirus is capable of invading testes, the study’s authors performed a complex genetic analysis of 6,500 testicular cells. They looked specifically for two genes, angiotensin-converting enzyme 2 (ACE2) and transmembrane serine protease 2 (TMPRSS2). These genes are used as receptors by the coronavirus, allowing the virus to enter cells and replicate itself. Both of these receptors must be present in a cell for the coronavirus to gain access.
Their analysis only showed the presence of these two genes in four out of the 6,500 examined testicular cells. In summation, the research team believe it is very unlikely that the coronavirus can invade a man’s testicles.
All that being said, they stress that their research was relatively small and held back by the fact that none of the 34 examined COVID-19 patients ever developed severe symptoms.
“It could be that a man who is critically ill with COVID-19 might have a higher viral load, which could lead to a greater likelihood of infecting the semen. We just don’t have the answer to that right now,” Hotaling adds. “But knowing that we didn’t find that kind of activity among the patients in this study who were recovering from mild to moderate forms of the disease is reassuring.”
Of course, just because the coronavirus isn’t lurking in sperm specifically, intimate contact like kissing still represents a big risk factor when it comes to potentially spreading the virus.
The study is published in Fertility and Sterility.