Florida Department of Health Officials have received reports of more than a dozen Eastern equine encephalitis (EEE) cases among horses so far this year, according to the agency’s weekly arbovirus surveillance reports.

In total, 16 Florida horses have tested positive for the virus since the first case confirmation in early January in Levy County; all of the affected horses have been euthanized, the reports indicate. Cases have also been confirmed in Lake, Gilchrist (four cases), Alachua, Madison, St. Johns, Columbia, Gilchrist/Columbia (the horse had been in both counties during the two weeks prior to onset), Hamilton, Bradford (two cases), Putnam, and Hernando counties.

In 2012 Florida confirmed 34 cases of EEE in horses.

A viral disease, EEE affects the central nervous system and is transmitted to horses by infected mosquitoes. Clinical signs of EEE include moderate to high fever, depression, lack of appetite, cranial nerve deficits (facial paralysis, tongue weakness, difficulty swallowing), behavioral changes (aggression, self-mutilation, or drowsiness), gait abnormalities, or severe central nervous system signs, such as head-pressing, circling, blindness, and seizures