Dengue is an illness caused by any of four closely related dengue viruses: DENV-1, DENV-2, DENV-3, and DENV-4. It spreads to people through the bite of an infected Aedes aegypti mosquito. Symptoms are often flu-like but without respiratory issues and may include a high fever lasting 5–7 days, body aches, pain behind the eyes, a rash, nausea, and vomiting. Not every patient experiences all of these symptoms.

Indian River Mosquito Control District inspectors search for containers that hold standing water, since these can become breeding sites for mosquito larvae.