Eastern equine encephalitis (EEE) case reports have risen into the hundreds this year, with confirmation of equine cases in at least nine states as the virus seemingly moves northwest from hot spots in the Southeast. Florida has been hit hardest, with a total of 174 equine cases reported from 47 counties as of July 25. The outcome of 163 of those cases is known: About 66% of those cases died or were euthanized. The EEE mortality rate is up to 90% in some areas and veterinarians continue to advise horse owners to vaccinate their animals against the disease.

EEE, which is spread by the bites of infected mosquitoes, began hitting the news this year in early April, when the first equine cases were reported in Florida. Bumper mosquito crops, warmer temperatures, and rains producing mosquito-breeding havens have been implicated in the unusual spread of the illness this year. However, veterinarians in the Southeast have said that the disease is cyclic and that they were due a difficult EEE year.
Other states experiencing their share of EEE include Alabama, Georgia, North Carolina, South Carolina, and Mississippi. Tennessee and Virginia have recently reported their first equine cases of EEE for 2003. On July 22, Indiana detected EEE in a robin