It has been confirmed that COVID-19 has the characteristic of human-to-human transmission, mainly through respiratory droplets and contact. Other routes require further verification. The virus responsible for COVID-19, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been detected in stool, gastrointestinal tract, saliva, and urine samples. However, little is known about SARS-CoV-2 in semen.
In a cohort study carried out by Diangeng et al., published in JAMA Network Open found that SARS-CoV-2 can be present in the semen of patients with COVID-19, and SARS-CoV-2 may still be detected in the semen of recovering patients. Owing to the imperfect blood-testes/deferens/epididymis barriers, SARS-CoV-2 might be seeded to the male reproductive tract, especially in the presence of systemic local inflammation. Even if the virus cannot replicate in the male reproductive system, it may persist, possibly resulting from the privileged immunity of testes.
The results contrast with a study of 34 Chinese men with COVID-19 published last month in the journal Fertility and Sterility. U.S. and Chinese researchers found no evidence of virus in semen tested between eight days and almost three months after diagnosis.
Evidence suggesting that other infectious viruses including Zika and Ebola may be sexually transmitted has prompted questions about the coronavirus.
So far, researchers have found 27 viruses associated with viremia in human semen. But the presence of viruses in semen may be more common than currently understood, and traditional non–sexually transmitted viruses should not be assumed to be totally absent in genital secretions. Studies on viral detection and semen persistence are beneficial to clinical practice and public health, especially concerning viruses that could cause high mortality or morbidity, such as SARS-CoV-2.
If it could be proved that SARS-CoV-2 can be transmitted sexually in future studies, sexual transmission might be a critical part of the prevention of transmission, especially considering the fact that SARS-CoV-2 was detected in the semen of recovering patients. Abstinence or condom use might be considered as preventive means for these patients.