As many as 93 million people in Latin America and the Caribbean, including 1.6 million childbearing women, could get the Zika virus over the next few years, according to a new startling study.
The study from the University of Notre Dame released Monday noted that the projections are a worst-case scenario. The study comes as federal and local officials are investigating what could be the first mosquito-borne cases of Zika in the U.S.
Researchers emphasized that the numbers in the study are infections, which aren’t the same as clinical cases.
“Only about 20 percent of people who are infected develop any symptoms whatsoever, and even fewer than that will seek medical care and show up in government statistics,” the researchers said.
The study didn’t use any data from the current epidemic. The researchers came up with the 93 million estimate by looking at past dengue and chikungunya outbreaks. Both diseases are spread via mosquito bites, just like Zika.
An estimated 53 million people were infected in 2010 in Latin America and the Caribbean, the study said.
“Our projections of nearly double this number for Zika are not surprising, given that there is extensive immunity to dengue but not Zika in this region,” the study said.
The study projects Brazil will have the most Zika cases, by more than double that of any other country, due to its size and suitability for transmission, it said. The outbreak first emerged in Brazil in May, and the country has more than 1 million Zika infections already.
As of June, five countries had 1,674 cases of microcephaly, the birth defect linked to Zika, the study said.
The goal of the study was to project a worst-case scenario of Zika infections. A recent estimate suggested that more than 5 million childbearing women live in areas of the Americas that are ripe for a Zika outbreak, the study said.
The study only looked at projections for South America and Latin American countries such as Mexico. It did not project the cases in the U.S., where there are already more than 1,300 Zika infections.
So far mosquitoes in the continental U.S. aren’t spreading the virus, and almost all of those cases are from people who got the virus in another country.
However, Florida health officials have identified two people with non-travel related Zika cases. The discovery prompted a federal and state investigation into how the victims contracted the virus, raising speculation that they are the first mosquito-borne cases in the country.
