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.
Screenshot from BBC News re: WHO rejecting the proposal to postpone or shift the Rio Olympics
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.
Rio is actually not at the epicenter of the Zika epidemic in Brazil.