Four cases of Zika virus infection in Florida have been confirmed to have been transmitted by local mosquitoes, a first in the continental United States since the global outbreak began, CNN reports. None of the four patients affected had traveled to a region outside of the U.S. that was known to have the Zika virus, nor had any of them had sexual contract with someone who had traveled to such a region, which leaves little doubt that the disease came from bites from local mosquitoes.
The patients, a woman and three men, live in Miami-Dade and Broward counties, but Florida Gov. Rick Scott said that to date, no mosquitoes in the state have actually tested positive for the virus.
More than 1,650 Zika infections have been reported in the United States, but these are the first four cases to not be linked to someone traveling outside the U.S. More than 60 countries and territories have reported Zika.
In June, the World Health Organization advised that visitors to regions that have the Zika virus consider delaying pregnancy. Zika has been linked to thousands of cases of microcephaly, a rare birth defect that causes babies to be born with abnormally small heads, as well as other severe brain defects. The WHO made its recommendation because there is no known treatment to keep pregnant women with Zika from transmitting the disease to their unborn babies.