Felipe Dana / AP
On Tuesday evening, Florida health officials announced that they are investigating what could be the first case of Zika in the continental U.S. that did not come from people traveling to other regions affected by the virus.
The officials did not say whether the new case, in Miami-Dade County, came from a mosquito bite or sexual transmission. (Miami-Dade has reported 88 other Zika cases that have come from travelers.) If it's confirmed to have come from a local mosquito, it could be the beginning of a U.S.-based outbreak.
In February, after Zika had caused a mysterious cluster of brain defects in babies in Brazil, the WHO announced a global public health emergency. Now, with the Rio Olympics looming, many athletes have decided not to attend, despite the fact that the winter season in Brazil means that mosquitos will be curbed and the virus unlikely to spread widely there.
Even if the Florida case means that local mosquitoes are indeed spreading Zika, U.S. health officials have predicted that the disease isn't likely to be as problematic in the U.S. as it has been in other countries because of screened windows and air conditioning.
Florida is working with the CDC to further understand the new case.