A staff member handles nucleic acid testing samples at a novel coronavirus detection lab in Wuhan, central China's Hubei Province, Feb. 22, 2020.Photo:Xinhua

Chinese researchers have detected COVID-19 in semen samples from male coronavirus patients. Whether or not the disease is sexually transmissible is unknown.

Researchers collected semen samples from 38 male COVID-19 patients. Test results revealed six patients' samples tested positive for COVID-19, according to a report published on JAMA Network Open on Thursday.

The six patients aged between 20 and 60. Four were at acute stages of infection while two had clinically recovered, the report said.

The report noted there were no significant differences between negative and positive test results in terms of the patients' age, urogenital disease history, time since the onset of infection, hospitalization duration, or recovery time.

It also noted that further studies are required with regard to virus shedding, survival time, and virus concentration in semen, as the study was limited by its small sample size and short subsequent follow-ups. 

A preliminary study by a Wuhan medical team found clinical evidence that COVID-19 could harm male reproductive gland functions by significantly increasing sex hormones, according to media reports in March. More research is needed to reach a definitive conclusion.

The coronavirus has also reportedly been detected in the blood and feces of COVID-19 patients, and in the tears of COVID-19 patients experiencing eye inflammation.