— -- The Florida Health Department is investigating whether a Zika virus infection in Miami-Dade County could be the first time the virus has been transmitted within the continental U.S. through infected mosquitoes.
The department is working with the U.S. Centers for Disease Control and Prevention to understand how the infected person could have been exposed to the virus in Miami. If confirmed to be a case of local virus transmission via an infected mosquito, it would be the first such case reported for the continental U.S.
The unnamed patient had not traveled to any country with ongoing-Zika infections, the health department said.
Puerto Rico has already been battling a widespread outbreak of the virus that is being locally transmitted.
There have been more than 1,300 people diagnosed with Zika in the U.S., but virtually all were infections contracted while abroad. A small number of cases were transmitted via sexual contact with partners who were infected abroad, according to health officials.
In order to be classified as a case of ongoing local Zika transmission there needs to be two cases of Zika infection within a one-mile diameter within a month that are both unrelated to travel or sexual transmission, according to the CDC.
Dr. William Schaffner, an infectious disease expert at Vanderbilt University Medical Center, said if the case is confirmed as a local transmission of the virus through infected mosquitoes, it would not be surprising.
"Everyone has said from the beginning is that there will likely be introductions and then subsequent local spread that is going to be very limited," of Zika virus, Schaffer said. "This sounds as though this may be the first instance of that."
Schaffner pointed out that to stop any possible outbreak, the health department will ask the infected patients to remain indoors so that they cannot infect mosquitoes that might bite them -- potentially leading to other infections. The CDC and Miami-Dade Department of health are also distributing Zika prevention kits and working with mosquito control to reduce the mosquito population in the area.