The Food and Drug Administration has asked all blood donation centers in Miami-Dade and Broward counties in Florida to halt blood donations until the blood can be tested for the Zika virus.
The decision comes as Florida officials are investigating four non-travel related cases of Zika in those counties, heightening speculation that the virus is now being spread by mosquito bites for the first time in the U.S.
The agency added that blood donation centers across the country should not accept donations from people who recently traveled to Miami-Dade and Broward, according to USA Today.
Florida officials have not confirmed that the cases were due to mosquitoes.
The U.S. has had about 1,400 cases of Zika, but almost all got it from a country where mosquitoes are spreading the virus.
In February, the FDA released guidelines for blood donations to ensure that the virus doesn’t contaminate the blood supply.
In areas without active Zika transmission, the FDA recommended donors at risk for Zika hold off for a month. In areas with active transmission, the agency recommends that blood and blood components for transfusion be obtained from areas of the U.S. without active transmission.
