The Zika virus has spread to a third county in Florida, as local officials on Wednesday reported a new case of local transmission in Palm Beach.

The virus has already spread to parts of Miami, and there has been a single case of local transmission in the Tampa Bay area. There are currently 43 non-travel related infections of Zika in Florida, likely from mosquito bites, which are the virus' primary mode of transmission.

The Florida Health Department announced the new case on Wednesday. It said the Palm Beach case was not linked to another case that popped up in the region.

In that instance, someone got the virus in the Miami neighborhood of Wynwood and then traveled back to Palm Beach. In the current case, the resident got the virus within Palm Beach and not from another area.

"One case does not mean ongoing active transmission is taking place," the department said.

It added that officials have begun testing and mosquito spraying in Palm Beach County, which is a couple of hours north from Miami.

Zika causes a mild illness for the person who is bitten, but has been linked to the birth defect microcephaly.