Conditions in Florida Ripe for Mosquito-Borne Diseases, UF Reports

GAINESVILLE, Fla. - Recent weeks of heavy rain have left conditions statewide ripe for a Fourth of July rife with mosquitoes. For some North Florida areas, however, the pests are more than a holiday annoyance - they bring the threat of the eastern equine encephalitis virus, known as EEEV.

"This year doesn't look like it's going to be tremendously unusual in terms of overall cases of mosquito-borne diseases," said Jonathan Day, a professor of medical entomology with the University of Florida's Institute of Food and Agricultural Sciences. "But transmission of [EEEV] tends to be very focal, and there are some areas that are looking risky."

EEEV is best known for being deadly in horses, but humans can contract the virus as well.

According to the national Centers for Disease Control and Prevention, the virus can cause a severe infection of the central nervous system in humans, and is fatal for nearly a third of those afflicted.

So far this year, 26 horses have been found to be infected in North Florida, with five more in the state's Panhandle.

These cases, along with analysis of weather conditions and other indicators, have led UF entomologists to believe that a band of counties beginning at Volusia County and stretching northwest into the Florida Panhandle carry a moderate to high risk of mosquitoes carrying the virus.

For an up-to-date risk map, please visit http://eis.ifas.ufl.edu/eis1.htm.

"July is usually the peak for EEEV transmission," said Roxanne Connelly, an IFAS professor of medical entomology. "We've had the type of weather patterns that can make the problem worse in some areas."

The disease is spread via mosquitoes that have fed on birds. Humans and horses cannot spread the virus to other humans and horses.

Connelly advises that people in risk areas avoid being outside during peak feeding times for mosquitoes that carry the disease - calm, humid periods from dusk to dawn.