The U.S. National Institutes of Health said it will fund a study to monitor U.S. athletes, coaches and members of the Olympic Committee staff for exposure to Zika virus while in Brazil, with the hope of gaining better understanding of how it persists in the body and the potential risks it poses.

The study, announced on Tuesday, seeks to determine the incidence of Zika virus infection, identify potential risk factors for infection, evaluate how long the virus remains in bodily fluids, and study reproductive outcomes of Zika-infected participants.

Brazil, which has been hardest hit by the mosquito-borne virus spreading across the Americas, will host the Summer Olympics in Rio de Janeiro next month.

The virus has caused concern because it causes potentially severe birth defects in babies whose mothers were infected during pregnancy, including microcephaly – a birth defect marked by small head size that can lead to developmental problems.

The study, which hopes to enroll at least 1,000 subjects, is being led by Carrie Byington, a Doctor at the University of Utah.

“We will follow individuals who have exposure to Zika virus for up to two years,” Byington said, “Because the cohort is anticipated to include primarily individuals in their reproductive years, we will be able to study reproductive health outcomes, including pregnancy outcomes.”

“We hope to identify risk factors and protective measures that may help other travelers avoid infection,” Byington said.

The connection between Zika and microcephaly first came to light last fall in Brazil, which has now confirmed more than 1,600 cases of microcephaly that it considers to be related to Zika infections in the mothers.

Zika is the first known mosquito-borne virus that can also be transmitted via unprotected sex with an infected male partner, leading to imprecise recommendations of how long couples should abstain or refrain from unprotected sex if the woman is pregnant or hoping to become pregnant.

The U.S. Olympic study could help answer some of the big questions surrounding Zika, particularly how long the virus remains present and transmittable in semen.