Florida health officials today said it is “likely” that four individuals in Miami-Dade and Broward counties in South Florida have been infected with Zika virus locally by mosquitos. These cases are believed to be the first of local transmission via mosquito in the continental U.S. The individuals had not traveled to areas where Zika is circulating or had any other known exposure to the virus. The U.S. Food and Drug Administration yesterday requested that all blood banks in Miami-Dade and Broward counties immediately suspend collecting blood until they can establish measures to test every unit collected for Zika virus. FDA also recommended nearby counties “implement the precautions above to help maintain the safety of the blood supply as soon as possible” and recommended that blood donation from donors who have traveled to Miami-Dade and Broward counties in the previous four weeks be deferred. For the latest on the Zika virus, visit http://www.cdc.gov/zika/index.html or http://www.aha.org/zika.