Blood donations in two counties in Florida have been halted by the FDA as there are now 4 possible cases of the Zika virus in the state. The big issue here is that signs are pointing to these being local cases, not travel related. Most Zika virus cases in the US have come from people traveling to countries in Latin and South America and bringing the virus back with them. The CDC has announced that evidence in these 4 new cases point to transmission via mosquitoes since they fit previous transmission patterns seen with other mosquito born illnesses, according to NBC news.

The FDA is suggesting that the counties outside of Miami-Dade and Broward should stop taking blood as a precaution. Until authorities can implement testing for each unit of blood collected or technology is developed that can kill pathogens in collected blood, the health authorities are doing what they can to keep the US blood supply safe.

In addition to mosquitos, the Zika virus is spread through blood transfusions and sex with an infected person.