US and China research shows the coronavirus is not present in semen samples, unlike Ebola and the Zika virus.
James M. Hotaling, MD
Coronavirus 2019 (COVID-19) was not detected in semen samples from recovered patients, leading investigators to believe the novel coronavirus likely is not sexually transmitted, according to a paper published in Fertility & Sterility.
Investigators from Wuhan and Salt Lake City collected semen samples from 34 adult Chinese males in order to describe COVID-19 detection in this post-infection population. The investigators wrote that the coronavirus has been found and isolated in bodily fluids such as blood samples and feces, so they wondered about viral shedding through other bodily fluids such as semen.
Other viruses, such as Ebola and Zika, could be sexually transmitted.
The samples were collected on average 1 month following diagnosis. The participants were diagnosed with mild to moderate COVID-19 between January 26 and March 2, and confirmed via PCR testing through pharyngeal swab samples.
They presented with symptoms such as fever, cough, pharyngodynia, and respiratory stress. Additionally, 6 patients reported scrotal discomfort around the time of COVID-19 confirmation.
The coronavirus was not detected in any semen samples, investigators determined, which led them to believe it is likely not sexually transmitted. However, just because the virus was not detected in the semen samples does not necessarily mean that the virus did not enter or impact the function of the testes.
“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,” study co-author James M. Hotaling, MD, associate professor of urology specializing in male fertility, at the University of Utah Health, said in a statement. “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.”
To further investigate the virus’ presence in the testes, the study authors attempted to detect ACE2 and TMPRSS2 genes, which, together, allow SARS-CoV-2 to penetrate cells and replicate. They compared data from young, healthy organ donors from prior research to their samples. They discovered that the genes were only found in 4 of the 6500 testicular cells they examined, which they said made it unlikely to invade human testicular cells.
“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,” Hotaling added, noting that none of the patients were critically ill among the small sample size in the study. “We just don't have the answer to that right now. 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.”
Investigators said more research is needed to determine the interactions between COVID-19 and the male reproductive function. They also warned that coughing, sneezing, and kissing could spread the virus—even those that appear healthy can be asymptomatic and pass the coronavirus to others.