Here’s a hint: June is National Congenital Cytomegalovirus Awareness Month.
In case that clue didn’t make it obvious enough, I’ll tell you the answer. The most common infection among developing fetuses is caused by a virus you might not have heard of: cytomegalovirus, or CMV. Around 30,000 children are born with this infection every year, and some of these babies will go on to develop serious problems because of it. National Congenital Cytomegalovirus Awareness Month is a time to learn about how CMV can affect pregnancy.
Cytomegalovirus can damage developing brain cells early in an embryo’s gestation.
This year, it might be of even greater interest, given the parallels that can be drawn between CMV and Zika virus, the emerging pathogen that has been dominating headlines lately. First of all, both CMV and Zika virus can be transmitted sexually, though they are not the first things you think of when the topic of STDs comes up, as they are overshadowed by more famous sexually transmitted viruses like herpes and human papillomavirus. While many of us are infected with CMV as children, we can also be infected as adults, often through sexual transmission — the virus can be found in cervical and vaginal secretions, saliva, and semen. The sexual transmission of Zika virus is not as well understood, but we know it can be found in semen, and there are documented cases of men passing the virus to sex partners through vaginal and anal intercourse. It might even be transmitted from a male to a partner by oral sex.
Second of all, both CMV and Zika virus are associated with birth defects. However, while the connection between CMV and birth defects has been known to us for decades, it was only in April that the Centers for Disease Control and Prevention concluded that Zika virus can cause fetal brain defects (though we’re still waiting for conclusive proof). Microcephaly is probably the most infamous of the birth defects associated with Zika virus, as well as CMV, but it’s not well defined. When you get down to it, though, microcephaly just refers to an abnormally small head, which itself might be indicative of a brain that has failed to develop fully. Continue reading