With many of the star members of the USA basketball team backing out of the Olympics, you have to question whether the Zika virus is the reason some players are not representing their country.
Some of the best players in the NBA have withdrawn their names from the team, such as Stephen Curry, Anthony Davis, James Harden and Russell Westbrook. With the cases of Curry and Davis, they have gone on and said they are not playing in the Olympics to recover from injuries. Now with Westbrook and Harden, they haven't stated why they are not partaking in the Olympics. Curry and Davis aren't the only two players missing due to injury: LaMarcus Aldridge (finger), Chris Paul (hand) and John Wall (knee). Chris Paul was a key factor in USA's 2008 and 2012 gold medal runs. Pau Gasol, who plays for his home country of Spain, isn't going to play in the Olympics die to the Zika virus.
According to the CDC, the most common symptoms of Zika are fever, rash, joint pain and red eyes. People don't usually get sick enough to go to the hospital, and rarely die of it. In May 2015, the Pan American Health Organization (PAHO) issued an alert regarding the first confirmed Zika virus infection in Brazil. On Feb. 1, 2016, the World Health Organization (WHO) declared Zika virus a Public Health Emergency of International Concern (PHEIC).
I am going to guess that basketball is played indoors, and they don't really have to deal with mosquitos. I would be more worried for track and field athletes. I believe from London that the long-distance running events take place through the streets of that city. I haven't heard anything about other sports athletes dropping out, just basketball.