MIAMI (AP) -- Federal authorities want to suspend blood donations in Florida counties investigating four mysterious cases of Zika infection that may be the first spread by mosquitoes on the U.S. mainland.
The U.S. Food and Drug Administration on its website asks blood centers in Miami-Dade and Broward counties to immediately stop collecting blood until each unit of blood can be screened for the virus.
Florida health officials have said the infections may not be linked to travel outside the U.S., but they haven't confirmed how the virus spread.
The FDA also recommended that neighboring counties implement the same precautions "to help maintain the safety of the blood supply as soon as possible." Visitors to the Miami and Fort Lauderdale areas in the last month are being urged to defer donations.