Florida Gov. Rick Scott on Friday said that Florida has become the first state in the nation to have the Zika virus transmitted locally via mosquitoes.
Gov. Scott said four cases of the virus in Miami Dade and Broward counties were likely local mosquito-borne cases of Zika, involving one woman and three men. He noted, however, that no mosquitoes in Florida have tested positive for the virus.
On Thursday, the Centers for Disease Control and Prevention said there was evidence that the virus was being transmitted in South Florida.
The mosquito-borne virus, which can cause a rare birth defect and other neurological conditions, has been spreading across the Americas and the Caribbean, with cases reported among travelers returning to the U.S.
These cases fit similar disease transmission patterns for other mosquito-borne diseases like chikungunya that's been seen in South Florida in years past, the CDC said in a statement.
Florida health officials said in a statement last week they were investigating a case of Zika virus infection that did not appear to stem from travel to another region with an outbreak.
U.S. officials predicted local outbreaks would begin as the weather warms, particularly in southern states such as Florida and Texas, according to Reuters.
There have been 1,658 reported cases of the virus in the continental U.S., according to the CDC. Zika, which can cause birth defects, is spreading more widely in U.S. territories, with nearly 4,700 cases in Puerto Rico alone. More than 430 pregnant women in the continental U.S. have been diagnosed with Zika, along with 422 in the territories, USAToday reported.
The CDC wants doctors to more aggressively screen pregnant women for the virus and take advantage of new testing technology to improve the diagnosis, follow-up and monitoring of those who have been infected.
The Florida Department of Health was not immediately available for CNBC's request for comment.
— Reuters contributed to this report.