MIAMI (CBSMiami) – Monroe County health officials have confirmed four new cases of Dengue fever in the county.

Officials said the affected individuals have received medical treatment and are expected to make a full recovery.

There are now a total of 21 confirmed cases of Dengue in Monroe County.

Epidemiological studies are being conducted to determine the origin and extent of these infections.

The Department of Health in Monroe and the Florida Keys Mosquito Control District are working to continue surveillance and prevention efforts including increasing mosquito control activities in the Key Largo (Upper Keys) area.

Dengue can present as a severe flu-like illness with severe muscle aches and pain, fever, and sometimes a rash. Usually, there are no respiratory symptoms.

Symptoms of Dengue will appear within 14 days after being bitten by an infected mosquito.

Dengue fever is not contagious but is transmitted by the bite of an infected Aedes aegypti mosquito.

Keys residents are urged to keep the area around their residences free from containers that collect water, wearing protective clothing, and use insect repellents.