Zika virus

Zika is a virus spread to people primarily when they are bitten by an infected Aedes species mosquito, but it can also be spread in a few other ways. Though the illness is usually mild, it can be spread from a pregnant woman to her fetus and may cause birth defects. Travelers can carry cases of Zika back from other countries, but since the mosquitoes that spread the virus don't live in Colorado, it is unlikely outbreaks will occur here.