Of the 550 Olympic athletes, more than half will be women. The volunteers include Olympic athletes, coaches and USOC staff. (Mike Ehrmann/Getty Images)U.S. officials are starting a massive effort to protect American athletes from Zika, even as they are learning more about the mysterious disease in real time. Everything you ever wanted to know about the Zika virus and its spread across North and South America. U.S. Olympic Committee officials have said the decision to attend the Games is up to individual athletes.

Source: Washington Post May 25, 2016 05:33 UTC