Research from the Yale School of Public Health estimates that — with as many as 500,000 people visiting Rio de Janeiro for the 2016 Summer Olympics — only 80 or fewer will be infected by the Zika virus. An even smaller number — between 3 and 37 — could bring the virus back to their home countries, researchers say.
The study echoes earlier statements by the World Health Organization, which has predicted the outbreak will slow as Brazil’s mosquito population subsides in the Southern Hemisphere’s winter.
“It’s important to understand the low degree of risk posed by the Olympics in the scheme of many other factors contributing to international Zika virus spread,” said Joseph Lewnard, a doctoral candidate and lead author of the paper published by the Annals of Internal Medicine.
Brazil has been hit particularly hard by Zika, which is carried mainly through mosquitoes. Though the virus is often mild, it has been linked to neurological disorders and birth defects in cases where pregnant women become infected.
Yale researchers constructed a mathematical model that accounted for recent transmission of the virus in Rio, seasonal conditions, travel patterns and other factors.
Of those infected, 16 or fewer are expected to show symptoms.
These findings contrast with an open letter from 150 professors, scientists and doctors who warned that visitors to the Games could accelerate the spread of the virus worldwide.
“This study provides data, which together with initial findings from Brazilian scientists, show that these concerns may be largely exaggerated,” said Albert Ko, chair of the school’s Department of Epidemiology of Microbial Diseases.
Some athletes — most notably in the sport of golf — have cited Zika as a reason for withdrawing from the Games.