Coronavirus may lead to infertility in men — even if they only suffer a mild form of the disease, scientists have claimed.
Sperm counts of infected men halved 30 days after they were diagnosed with Covid-19, according to a study.
According to the researchers in Israel, where the study was conducted, sperm motility — or its ability to move by itself — was also hampered.
Experts say mild symptoms are those that don’t leave the patient requiring hospitalisation, and can include a fever and new continuous cough.
The research was published in the journal of Fertility and Sterility, according to the Jerusalem Post, which reported halving in sperm levels was in half of mild cases.
But the journal has yet to publicly release the paper, meaning top scientists from around the world have yet to be able to point out obvious flaws in its method.
Scientists studying the effect of coronavirus on fertility have, however, made similar claims in the past.
But doctors insist reports of men having lower sperm counts are likely down to them having had a fever — a tell-tale symptom of coronavirus.
This, scientists say, makes it harder for the body to produce sperm. They also argue that production can bounce back after an infection has passed.
Professor Allan Pacey, an andrologist at the University of Sheffield and former chair of the British Fertility Society, told MailOnline he wouldn’t be surprised if coronavirus caused a temporary drop in sperm production.
But the jury is still out on whether or not the effect could be long-lasting, harming the fertility of men.
“People who get coronavirus are probably quite unwell, even influenza will cause a decline in sperm count temporarily,’ he said. “The question is whether it is permanent and whether it is recoverable.”
Research is yet to reveal whether long-term damage can be caused to testicles by coronavirus, and it could take several years before scientists have the answer.
Previous research has indicated, however, that any damage caused to the testes by an infection is not long-term.
Professor Pacey cautioned against the finding in the new Israeli research that coronavirus can damage cells in the testicles responsible for making semen and the male hormone testosterone. The doctors claimed that was the case after examining 12 men who had died from the virus. But Professor Pacey pointed out deceased patients would have been much sicker.
“There’s a bit of caution there because if you’re in ICU and you die you’re very sick, so we shouldn’t be surprised if there are changes in the testicles,’ he said. ‘Also, men who get very sick and are in ICU tend to be older,” he said
“The main site of virus replication is the respiratory tract,’ he said. ‘(Travel in the bloodstream) has been reported for the virus but it is not generally what coronaviruses do.”
Professor Pacey said he can’t see a mechanism whereby coronavirus would become blood-borne. “I may be wrong, this is a new virus, we’re learning all the time,” he said.