Mosquitos carrying deadly, brain-swelling virus detected in Florida

A potentially deadly mosquito-borne virus known to cause brain swelling has been detected in Florida, according to the state's health department.

The disease, known as Eastern equine encephalitis virus (EEEV), was found in a number of chickens last week. Officials have warned that the risk of transmission to humans has increased.

EEEV is one of a group of mosquito-transmitted viruses that can cause encephalitis, or inflammation in the brain, according to the Centers for Disease Control and Prevention (CDC) website.

The CDC warns that approximately one-third of all EEEV cases are fatal, and many people who survive sustain mild to severe brain damage. Symptoms typically appear abruptly and can include chills, fever, joint pain and muscle pain.

The virus has traditionally been uncommon in the U.S. — with an average of just five to 10 cases reported each year — but some individuals are more vulnerable than others.

"Persons over age 50 and under age 15 seem to be at greatest risk for developing severe disease when infected with EEEV," the CDC's website says.

Florida, Massachusetts, New York and North Carolina have reported the largest number of cases over the past decade. The Florida Department of Health in Orange County (DOH-Orange), which issued the original warning about EEEV, also shared general guidelines for avoiding mosquito-borne diseases.

DOH-Orange recommends that people remember to "Drain and Cover" as a way to defend against mosquito-borne illnesses.

"Drain" refers to regularly draining water from gutters, garbage cans, pool covers, boats and anywhere else where the presence of stagnant liquid could help mosquitoes multiply. "Cover" simply refers to covering bare skin with clothing and insect repellant, as well as using mosquito netting to protect children less than 2 months old.