This summer’s Olympic Games in Rio de Janeiro won't impose a significant additional risk of transmission of the Zika virus for most of the world, according to a new report released this morning from the U.S. Centers for Disease Control and Prevention.
Because travel for the Olympics represents less than 0.25 percent of total travel to Zika-affected countries, and because the Games' August and September dates come during Brazil’s winter months, when mosquitoes are less prevalent, the Games themselves represent a very low additional risk for transmission, the CDC found. Even though the Brazilian Tourism Board forecasts approximately 350,000 to 500,000 international visitors for the Games, the CDC says that travel to the last four summer Olympics didn't exceed normal travel patterns to the host cities.
Four countries identified in the report will face a higher risk. Chad, Djibouti, Eritrea, and Yemen do not currently have many travelers to countries with local Zika virus transmission, so travel to Brazil represents a bigger jump in the risk for them.
Using a risk-analysis model that included such factors as countries’ current Zika transmission rates, climate, and estimated mosquito populations, the CDC was able to assess what kind of additional public health risk is presented by the Games. The report offers a rare bit of good news for the Rio Games, whose success is challenged not only by Zika but also by crime, major financial setbacks and environmental pollution.
The report still advises pregnant women not to travel to the Games and to use condoms every time they have sex with a man who has traveled to Zika transmission areas. All travelers should take precautions to protect themselves from mosquito bites, such as using insect repellent.