With only a few weeks left until the 2016 Olympic Games get underway in Rio de Janeiro, officials at the Centers for Disease Control and Prevention are urging anyone traveling to the Olympics to take precautions to avoid contracting Zika virus infection or spreading it when they return home.
But the CDC estimates that there is a low probability of mosquito-borne Zika virus infections during the Olympics because Rio will be experiencing cooler, drier weather then, which typically reduces the mosquito population.
Along with lower mosquito activity, the CDC said that the number of visitors expected in Brazil for the Olympics represents only a fraction of the total travel volume to Zika-affected countries during 2015. The Brazilian Tourism Board is expecting anywhere between 350,000 and 500,000 visitors for the Olympic Games, coming from 207 countries. That represents less than 0.25% of the total travel volume to Zika-affected countries during the entirety of 2015, according to the CDC.
There are 19 countries that the CDC deems susceptible to sustained mosquito-borne transmission of the Zika virus, should the virus enter the country via an attendee of the Olympics (MMWR. 2016 Jul 13. doi: 10.15585/mmwr.mm6528e1).
Of these 19 – none of which are currently experiencing a Zika outbreak – 15 are “not estimated to increase substantially the level of risk above that incurred by the usual aviation travel baseline for these countries.” This leaves Chad, Djibouti, Eritrea, and Yemen at an elevated risk for a Zika outbreak. These four countries “are unique in that they do not have a substantial number of travelers to any country with local Zika virus transmission, except for anticipated travel to the Games,” according to the CDC.
The CDC is urging travelers to take protective measures for their entire stay in Rio and for at least 3 weeks after returning home. The measures include applying mosquito repellent, wearing long-sleeved shirts and long pants, staying in rooms that are air conditioned, and using either screen doors or a mosquito net for additional protection. Additionally, all travelers should take measures to prevent sexual transmission. The CDC continues to advise pregnant women not to travel to the Olympics.