The FDA is getting even more serious about stopping the spread of Zika, recommending Friday that all blood donations in the US be screened for the virus, USA Today reports. Previously, it had recommended screening donations only in areas where Zika was spreading—mostly Florida and Puerto Rico. According to NPR, none of the more than 2,000 Zika cases in the continental US have come from tainted blood transfusions, but at least one unit of donated blood in Florida tested positive for the virus.
“At this time, the recommendation for testing the entire blood supply will help ensure that safe blood is available for all individuals who might need transfusion," says an FDA statement. Eleven states are asked to start testing their blood donations within the next four weeks. Those are: Alabama, Arizona, California, Georgia, Hawaii, Louisiana, Mississippi, New Mexico, New York, South Carolina, and Texas. The rest are asked to start testing within 12 weeks. (Read more Zika virus stories.)