Researchers at the University of Miami are studying whether COVID-19 can be sexually transmitted.
So far, they have found COVID-19 can invade the male testicles and linger.
Fertility specialist Ranjith Ramasamy and his colleagues at the University of Miami Miller School of Medicine looked at tissue from autopsies of six men who died with the COVID-19 infection and found the virus was still in their testicles. They also found COVID-19 in the testicles of a male patient who had the coronavirus and recovered without showing symptoms.
In the men studied, about half the time the virus inhibited their sperm function.
"What most surprised us is the fact the virus can be present in the testes of asymptomatic men and linger long after they test negative, even if they have no testicular pain," Ramasamy said.
It makes sense that the testicles, which are responsible for sperm and testosterone production, are a target for COVID-19 infection because of the way the virus attaches to organs, Ramasamy said. The receptor in the testes (ACE-2) in which the virus attaches is the same one as in the lungs, heart, intestines and kidneys, where it has been known to cause damage.
The UM researchers published their findings Thursday in the World Journal of Men's Health.
"This study is the first step in that process and opens the door to important research to pursue, especially in South Florida," Ramasamy said.
Ramasamy said his Miami research group has gone on to study the semen of 30 men between ages of 30 and 55 during the three- to six-month period after they recovered from COVID-19. They wanted to know whether the virus could lead to male infertility and be sexually transmitted.
"If you have a small viral load, you may be OK," Ramasamy said.
But because men without symptoms of COVID-19 don't know their viral load and may continue to be sexual, they could transmit the virus to their partner or affect their long-term ability to reproduce. As much as 30% to 40% of men are asymptomatic and could potentially spread the virus to their partner without knowing, he said.
"Some young college students are worried. We have had a few requests from guys who want to freeze sperm with the fear of getting COVID in future," he said. "They may have no symptoms now, but they could see it affect them down the road when they attempt to have kids."
Ramasamy said he will be publishing the results of the second study soon.
The Miami doctors are not the only ones studying this effect of COVID-19. New York researchers also have published studies that conclude men who have had COVID-19 might develop sexual and reproductive health issues.
A study published in the journal Fertility and Sterility found no evidence of the COVID-19 coronavirus in the semen from men who had recovered from the infection. However, this study looked at 34 men with researchers checking the semen a median of 31 days after each person had been diagnosed with COVID-19. The study did not rule out the possibility that the virus was in semen earlier in the infection.
Ramasamy said to better understand the long-term effect of COVID-19 on men, more studies are needed.