Florida continues to lead the United States in the number of cases of Eastern equine encephalitis
(EEE), a mosquito-borne disease that had mortality rate of around 90% in horses.
As of Aug. 11, Florida had reported 48 cases. Other Southern states reporting cases included Georgia (29), Mississippi (21), North Carolina (8), and Alabama (6).
Virginia reported four cases, Texas had three, and Minnesota had one.
In 2008, there were 185 equine cases of Eastern equine encephalitis reported from 15 states. Florida topped the year-end tally with 89 cases.
EEE is transmitted through the bite of an infected mosquito that has picked up the virus by feeding on an infected bird. Horses are "dead end" hosts of the virus--they cannot infect other animals, but can serve as signals that the virus is active in the area.
Clinical signs of EEE in horses include depression, ataxia, circling, and recumbency. The virus causes swelling of the brain. Humans can also be infected.
Veterinarians recommend that horses be vaccinated to protect against mosquito-borne diseases such as West Nile virus and Eastern and Western equine encephalitis as part of their routine health care program. There is no human vaccine.
The Centers for Disease Control (CDC) provides weekly reports of arbovirus case information from its ArboNET reporting system. Access these reports through the USDA Animal Health Monitoring and Surveillance Web site.
Disclaimer: Seek the advice of a qualified veterinarian before proceeding with any diagnosis, treatment, or therapy.