The Food and Drug Administration now recommends that all blood donations in the U.S. be screened for the Zika virus.
The FDA previously advised screening only in areas with active Zika transmission, like parts of Florida and throughout Puerto Rico.
But the agency's acting chief scientist said in a statement Friday, "As new scientific and epidemiological information regarding Zika virus has become available, it's clear that additional precautionary measures are necessary."
FDA officials say blood collection sites in Puerto Rico and parts of Florida are already testing for Zika. Several blood centers have started screening for the virus voluntarily, including several in Texas.