Mosquito season already is upon us as summer rains begin. The Florida Department of Health is advising state residents to be especially alert to symptoms of mosquito-borne viruses during the summer months. Mosquito-borne disease surveillance in Florida focuses particularly on West Nile virus, Eastern equine encephalitis and dengue fever.
West Nile virus infection unfortunately usually does not show any symptoms at all. At most 20 percent of people infected with West Nile will show symptoms, usually mild. These may include fever, headache, body aches, nausea, vomiting, and sometimes swollen lymph glands development of skin rash on the chest, stomach and back. Only about one person in 150 will develop severe illness. This is characterized by high fever, headache, neck stiffness, stupor, disorientation, coma, tremors, convulsions, muscle weakness, vision loss, numbness and paralysis.
Symptoms of West Nile virus infection will show up anytime from three to fourteen days after being bitten by an infected mosquito. If you develop symptoms, such as unusually severe headaches or confusion, you should seek medical attention immediately. Severe West Nile virus illness usually requires hospitalization. Pregnant women and nursing mothers especially should consult their health care provider if they develop symptoms.
Eastern equine encephalitis occurs primarily among children and older adults. Children younger than 15 years of age and persons over 50 are the most at risk. Most people show no symptoms when infected. Those who do usually experience only a mild flu-like illness with fever, headache, and sore throat. People who suffer infection of the central nervous system will develop a sudden fever and severe headache, which can be followed quickly by seizures and coma. About half of these patients die from the disease. Symptoms usually appear 4 to 10 days after being bitten by an infected mosquito.
Dengue fever is found primarily in sub-tropical climates. The symptoms are high fever, severe headache, severe pain behind the eyes, joint pain, muscle and bone pain, rash, and mild bleeding. Bleeding may occur from the nose or gums, or it may manifest in the form of easy bruising. Persons who think they have dengue fever should use pain relievers with acetaminophen, but should avoid aspirin. Dengue sufferers also should rest, drink plenty of fluids and consult a health care provider.
Health and environment specialists advise state residents to take special care in prevention of mosquito propagation around home. Improperly maintained rain gutters become major breeding places for mosquitoes. Old tires and tire swings, buckets, empty planters, plant trays, hanging plants, bird baths, pet dishes, tarps, boat bilges and low spots in a yard all serve as mosquito breeding places as well.
Tips on mosquito prevention, along with more detailed information about mosquito-related health risks, is available from the Department of Health at floridashealth.com .
Information on the above mosquito borne diseases also is available from the Centers for Disease Control and Prevention at the following webpages: Easter Equine Encephalities , West Nile Virus , Dengue Fever .
These webpages are current and supercede any pages previously posted by the National Center for Infectious Diseases. NCID has been eliminated and its public information postings have been realigned into multiple national centers of the CDC. Any NCID postings that remain online at this time serve archive purposes only.