Veterinarians are scrambling to keep up with the alarming number of Eastern equine encephalitis cases emerging in the southeastern United States. Since the beginning of June, South Carolina has had 17 confirmed equine cases, with about 25 pending confirmation. Florida's EEE case count is up to 113 horses this year, and Georgia has 30.
In 2002, South Carolina had five equine cases of EEE, Florida had 25, and Georgia had six.
Venaye P. Reece, DVM, equine programs coordinator and state animal emergency response coordinator with South Carolina's state veterinarian's office, said, "We've been due a high Eastern (equine encephalitis) year. It tends to be cyclic--it runs in 10-year cycles. Our last big year was 1991. We're getting clobbered."
Reece said that the actual number of EEE cases is always higher than the number of reported and confirmed cases. She said that almost none of the horses were vaccinated, or they were not current on their vaccinations.
Reece reports that every confirmed S.C. equine case has died or has been euthanized. The state's Department of Health and Environmental Control and the USDA's National Veterinary Services Laboratory in Ames, Iowa perform testing on suspect cases.
"The good news is that we have a very good vaccine available for EEE and West Nile virus, but horse owners have to give it early and appropriately," stated Reece. "Our problem now is that we're in the midst of an outbreak, and some people are just now (vaccinating)." Vaccinating just prior to or immediately following exposure to the virus might not be protective.
"It really hurts to lose a horse to EEE," said Reece. "The vaccine for it is very inexpensive, so it's complacency or lack of effort (that leads to these cases)." She emphasized the importance of mosquito control via pesticides, larvicides, and by eliminating areas of standing water that encourage mosquito breeding.
EEE is a virus transmitted by the bite of infected mosquitoes. Reece said the state's EEE season would typically peak in late August or early September, but this year, it will probably peak in July and early August.
Reece added, "The (EEE) numbers are going to continue to climb, and at some point this (disease focus) is going to shift to West Nile virus. We haven't had a positive West Nile virus horse yet (as of June 27)."