People with COVID-19 can pass on the virus through droplets released when they cough or sneeze. This sparked concerns that all bodily fluids may help spread the novel coronavirus.
A new study, published in the journal Fertility & Sterility, suggests that semen may not be part of the list. Researchers found that in most male patients the coronavirus did not reach the testes.
The findings come amid growing claims that COVID-19 could be sexually transmitted like Ebola and Zika. The research team from China and the U.S. looked into semen samples from 34 men who tested positive for the coronavirus.
Researchers focused on the expression of two genes associated with the virus, called angiotensin-converting enzyme 2 (ACE2) and transmembrane serine protease 2 (TMPRSS2). They help the coronavirus to enter and replicate in cells.
But in men who were diagnosed with COVID-19, researchers did not detect a significant amount of virus in their semen samples. The two genes were present in only four of the 6,500 testicular cells.
“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,” James Hotaling, study co-author and associate professor at 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.”
However, the researchers noted their study has some limitations. The team examined semen samples from a small number of patients and none of the men were severely ill with COVID-19.
“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 said. “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.”
But the researcher noted intimate contact with an infected person may still put people at risk of contracting the novel coronavirus. That is because of exposure to droplets when they kiss, cough or sneeze.