Why Massive Zika Spread is Unlikely at the Olympics

Having the Rio 2016 Olympics in a country with an ongoing Zika epidemic has some athletes and physicians concerned. But a growing number of scientists are predicting few new infections from the virus during the Games.

A new report, published Monday in the journal Annals of Internal Medicine, predicts that in a worst-case scenario there will be between six to 80 new cases of Zika among travelers at this summer’s Olympics. “Because few pregnant women likely will attend the events owing to travel advisories, these estimates reiterate previous statements of the low personal effect of [Zika virus] on travelers,” the study authors write.

Why might infections be so low? The authors of the new study argue that people who are attending the Games are at a lower risk of being exposed to Zika compared to the general Brazilian population since they will, for the most part, be staying in areas that have screens and air conditioning. August is also winter in Brazil, and health experts have said that the number of biting mosquitoes will likely be down. Active mosquito control, like regularly removing stagnant water, is also expected at the Olympic venues.

The new study isn’t the first to provide low estimates of infection. At least two other studies have predicted less than 20 new infections, using a variety of estimation models. As TIME has previously reported, infectious disease experts have expressed a low level of concern about mass spread of the disease from the Games for some time. Since millions of people have already traveled between Brazil and other countries during the height of the outbreak, some scientists say that much of the virus’ introduction into other countries has already happened.

Health authorities are still urging travelers to take the virus seriously. In the U.S. over 1,400 travelers are infected and there are close to 800 pregnant women in the U.S. and territories with the virus. Health authorities recommend that people also protect themselves from mosquito bites when they return to their home country, so that if they do contract the virus, they don’t spread it to local mosquitoes. Local transmission of the virus is expected in the United States, but not at the scale of Brazil.