Four African countries are at the highest risk of a Zika outbreak if one of their athletes or travelers is infected with the virus during the upcoming Summer Olympics in Brazil, according to American health officials.
A risk analysis published by the Center for Disease Control and Prevention on Wednesday said factors common to Chad, Djibouti, Eritrea, and Yemen could lead to a sustained spread of Zika in those countries.
There isn't a "substantial" amount of travel by people from these countries to Zika-affected countries aside from their participation in the Games, and they all have the "environmental conditions and population susceptibility to sustain mosquito-borne transmission of Zika virus," said a CDC news release.
"Except for these four countries, the 2016 Olympic and Paralympic Games do not pose a unique or significant risk for further mosquito-borne transmissions of Zika virus in excess of that posed by non-Olympic travel," the report said.
About 350,000 to 500,000 international visitors and athletes from 207 countries are expected to visit Rio de Janeiro for the Olympic and Paralympic Games, representing less than 0.25 percent of the total estimated travel to Zika-affected countries in 2015, according to the Brazilian Tourism Board. The games start August 5.
But the probability of visitors being infected with the mosquito-borne virus is low since the Games are happening during what is winter in Brazil, when the mosquito population is lower because of the cooler and drier conditions, said the CDC news release.
The center still recommends, however, that pregnant women not travel to the Games, that all visitors take steps to prevent sexual transmission and mosquito bites during the Games and for 3 weeks after returning home.
Follow Tamara Khandaker on Twitter: @anima_tk