We still have a lot to learn about the Zika virus; after all, scientists have only recently found that babies born to mothers infected with the virus will suffer microcephaly, or “shrunken heads.”
For example, new research has determined that Zika can shrink testicles and damage them to the point that sperm production drops dramatically. In research reports released this week, scientists say that the Zika virus can do this, at least in lab mice. There is no way of knowing, at this time, how this might translate to a larger mammal (like humans).
Still, there is concern. Washington University fertility specialist Dr. Kelle Moley explains, “This is the only virus I know of that causes such severe symptoms of infertility.”
The study co-leader goes on to say, “There are very few microbes that can cross the barrier that separates the testes from the bloodstream to infect the testes directly.”
Mumps, for example, is among the most notorious causes of male infertility in the world. This virus can cause swelling and pain within the testicles and, thus, damage fertility, but this only occurs in a relatively small percentage of infected men. He also notes that the Ebola virus can sometimes get into the semen and remain in the testes for months.
As such, the team tried to see if the virus caused damage to the testes while it resided there, even as a passive body. In mice, Moley says, “What we found was that by day seven you could already detect the virus there and it was cleared by day 21.”
More importantly, he continues, “you could see a progressive destruction of the cells in the testes. So by day 21 the testes was about a tenth of the size of what it originally was. As a result there was no sperm.”
Similarly, study author Michael Diamond inquires, “What we don’t know is does it also cause the same level of injury?” And, therefore, if a man does not have any symptoms, are his testicles, in fact, damaged? if a man doesn’t have symptoms, can his testicles be damaged? He asks, “Does the degree of severity of infection correlate with injury?”
The United States Centers for Disease Control and Prevention reports approximately 4,000 Zika cases across the 50 states and in excess of 28,000 territories—mostly Puerto Rico.