Traces of the COVID-19 coronavirus have been found in the semen of some severely infected men, raising the possibility that the virus might be sexually transmitted, a new study from China claims.
Researchers found evidence of the virus in six men out of a group of 38 COVID-19 patients at Shangqiu Municipal Hospital in China who provided samples.
The six men included four who were still infected and two who were recovering, the researchers said.
The study was led by Dr. Weiguo Zhao of the People’s Liberation Army General Hospital in Beijing, and findings were published May 7 in the journal JAMA Network Open.
It’s not surprising that the virus was found in semen samples, since it’s also been found in stool and other body fluids, said Dr. Ryan Berglund, a urologist with the Cleveland Clinic’s Glickman Urological and Kidney Institute.
Infectious viruses commonly are found in semen, with Zika being one recent notable example. The Chinese researchers noted that 27 different viruses have been detected in human semen.
However, Berglund and infectious disease experts warn that this does not constitute concrete evidence that COVID-19 can be sexually transmitted.
“I think that’s premature,” Berglund said. “You have to look at this as a sign that semen, as along with a number of other body fluids, can contain the virus.”
The new paper comes on the heels of another study from China that found no traces of coronavirus in 34 men with mild to moderate cases of COVID-19. That study was published in late April in the journal Fertility and Sterility.
Dr. Amesh Adalja, a senior scholar with the Johns Hopkins Center for Health Security in Baltimore, said “the fact that the novel coronavirus’ genetic material is found in the semen of male patients is an important finding that will need follow-up study.”
Agreeing with the need for further research is Dr. Greg Poland, director of the Vaccine Research Group at the Mayo Clinic in Rochester, Minnesota.
“To me, it raises a warning, and now we have to attend to that warning and do the research,” Poland said.
But both Adalja and Poland have doubts about the potential for COVID-19 to be sexually transmitted.
“We know the virus is transmitted efficiently through the respiratory route and we have not seen any documented cases of sexual transmission, therefore this may not necessarily represent proof of sexual transmissibility via the male genital tract,” Adalja said.
Poland noted that the new study relies on testing that only detects traces of genetic material from the coronavirus.
“It doesn’t tell you that it’s whole, viable, infectious virus,” Poland said. “If I ground up the virus and performed this test, it would be positive even though that virus has no infectious potential.”