Chinese researchers have found Covid-19 in the sperm of a small number of men, raising the possibility that the virus could be spread via sex.

The study by physicians at China's Shangqiu Municipal Hospital looked at only 38 men at the hospital who had tested positive with disease, and of that already small group found that a minority " only six " were found to have SARS-CoV-2 in their semen.

"The virus responsible for Covid-19, severe acute respiratory syndrome coronavirus 2, has been detected in stool, gastrointestinal tract, saliva and urine samples," the researchers' report said. "However, little is known about SARS-CoV-2 in semen."

While the study published by JAMA Network Open " an online, open-access medical journal " was small and hardly definitive, researchers say it points to the need for further research into how the virus is spread and how likely it is to be transmitted sexually.

"If it could be proved that SARS-CoV-2 can be transmitted sexually ... [that] might be a critical part of the prevention," the team wrote in the JAMA, "especially considering the fact that SARS-CoV-2 was detected in the semen of recovering patients."

Their findings come as other similar-sized studies have found that minor or no traces of the virus remain in infected men's sperm, giving experts pause, with researchers cautioning that the findings are only preliminary and far from conclusive.

"This study is limited by the small sample size and the short subsequent follow-up," wrote the doctors, "therefore, further studies are required."

Even if coronavirus is found to be present in sperm more broadly, that doesn't necessarily mean that it is sexually transmissible, Allan Pacey, a professor of andrology at Britain's Sheffield University, said in an interview with Reuters.

"We should not be surprised if the virus which causes Covid-19 is found in the semen of some men," said Pacey, "since this has been shown with many other viruses such as Ebola and Zika."

At the very least, studies like these point to how much there still is to learn about coronavirus and how it spreads. According to the study, findings like these open up the possibility for medical workers that "to avoid contact with the patient's saliva and blood may not be enough".

This article originally appeared in the South China Morning Post (SCMP), the most authoritative voice reporting on China and Asia for more than a century. For more SCMP stories, please explore the SCMP app or visit the SCMP's Facebook and Twitter pages. Copyright © 2020 South China Morning Post Publishers Ltd. All rights reserved.

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