Miami-Dade County reported four more cases of West Nile virus Friday, bringing the county's total to 18 so far this year.
The Florida Department of Health said in a news release that the county is under a mosquito-borne illness alert as the virus was confirmed in four Miami-Dade residents.
West Nile virus (WNV) is the leading cause of mosquito-borne disease in the continental United States and is most commonly spread to people by the bite of an infected mosquito. There are no vaccines to prevent or medications to treat WNV infections in people.
Most people infected with West Nile virus -- which is most commonly spread to people by the bite of an infected mosquito -- do not feel sick.
About one in five people who are infected develop a fever and other symptoms such as headache, pain and fatigue. People with mild illness typically recover within about a week with symptomatic treatment. Less than 1% of infected people develop a serious, sometimes fatal, illness.
Health officials are reminding the public to take preventative measures against mosquitos and remember to "drain and cover."
More info can be found on the DOH website.