This year, the virus looming over the Rio Olympics is Zika. But mosquito-borne virus experts have repeatedly said they don’t think Zika is a big risk for Olympics tourists—for several reasons. It’s actually winter in Rio, so mosquito season is at a lull, and the country’s Zika hot spot is hundreds of miles away in the north. [SEE MY BLOG POST A FEW DAYS AGO ABOUT THIS] Brazilian authorities are also rooting out mosquito breeding grounds and fumigating any Olympics venues where mosquito-borne virus cases pop up.
The Olympics could test whether all these assumptions about Zika spread hold true—or reveal some totally new information about the virus’ movement. “When it comes to infectious diseases, we don’t actually know a lot about how they spread from person to person,” says Gardy. “With the nitty gritty, there’s a lot not understood.”
And it’s not just about Zika. The WHO is watching the Olympics for less novel diseases, too: other mosquito-borne viruses like dengue and yellow, food poisoning, and seasonal flu. August is the tail end of flu season in the southern hemisphere. Because the northern and southern hemisphere have different flu seasons, strains that circulate can be different, too. That’s why every year, flu vaccine manufacturers make two versions: one for the northern and one for the southern hemisphere. This year, the flu in Brazil happens to be covered by the northern hemisphere vaccine. Otherwise, it would be more cause for worry.And then there is the polluted bay in which people will be rowing, and toilets that don't work in various places where athletes and visitors are staying. If you want to study the spread of disease, this is definitely the place to set up camp.
UPDATE: Thanks to Rebecca Clark at NICHD for pointing me to a study that they are funding of U.S. Olympic athlete and coach exposure to the Zika virus.
Researchers supported by the National Institutes of Health will monitor potential Zika virus exposure among a subset of athletes, coaches and other U.S. Olympic Committee (USOC) staff attending the 2016 Summer Olympics and Paralympics in Brazil. The study, funded by NIH’s Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) and led by Carrie L. Byington, M.D., from the University of Utah, Salt Lake City, aims to improve understanding of how the virus persists in the body and to identify potential factors that influence the course of infection.