In an open letter to the World Health Organization, 177 (and counting) international scientists and bioethicists –  including one from Singapore – have called for the Olympic and Para-Olympic games to be either postponed or shifted from its current site in Rio de Janeiro, Brazil. Their concern is that holding the Olympics in Rio as scheduled would accelerate the spread of the Zika virus globally, given that more than half a million people from around the world are expected to converge and then disperse from Brazil during the Olympics, and that Brazil is nowhere near controlling the Zika outbreak in Rio.

The WHO has rejected the call to do so, and this is supported by both CDC Atlanta and the European CDC. In fact, the European CDC has produced a technical assessment putting forth reasons why it believes that the risk of acquiring Zika in Rio during the Olympics is actually very low:

1. The Olympics will take place in August, which is winter season in Rio. The cooler and drier weather then will be anathema to mosquitoes, which tend to flourish and spread between November and March when rainfall is highest.
2. Rio is actually not at the epicenter of the Zika epidemic in Brazil.

Interestingly, there was a similar concern with dengue at the World Cup held in Brazil in July 2014. Subsequent research confirmed that the risk of dengue transmission during the World Cup was actually very low. Because Zika spreads in the same way as Dengue, i.e. via an infected Aedes mosquito, it would make sense that there would similarly be very limited transmission of Zika during the Olympics in August this year.