In a follow-up on the Eastern Equine Encephalitis (EEE) situation in the state of Florida, the Florida Department of Agriculture and Consumer Services confirmed positive tests for seven horses in July:

Florida map/National Atlas of the United States
Florida map/National Atlas of the United States

On July 2nd, a six-month old unvaccinated Tennessee Walking Horse stallion in Okeechobee County became clinical on June 11th and was humanely euthanized on June 12th due to a poor prognosis. On July 3rd, a four-year old unvaccinated miniature horse mare in Osceola Countybecame clinical on July 2nd and was humanely euthanized on the same day due to a poor prognosis. On July 10th, a nine-year old Friesian mare in Jackson County became clinical on July 2nd and has made a full recovery. On July 17th, a two-year old unvaccinated Quarter Horse stallion in Union County became clinical on July 3rd and was humanely euthanized on July 5th due to a poor prognosis. On July 17th, a one-year old unvaccinated Paso Fino mare in Polk County became clinical on July 9th and was humanely euthanized on July 11th due to a poor prognosis. On July 18th,a three-year old Quarter Horse mare in Suwannee County became clinical on July 14th and was humanely euthanized on the same day due to a poor prognosis. On July 20th, a one-year old Warmblood mare in Clay County became clinical on July 10th and was humanely euthanized on the same day due to a poor prognosis.

Through July 21, Florida health officials have reported positive samples from one human from Taylor County in May, forty-four horses, one mule, one donkey, one owl, one emu, five emu flocks, two mosquito pools, and one hundred five sentinel chickens have been reported from thirty-one counties.

EEE causes inflammation of the brain tissue and has a significantly higher risk of death in horses than West Nile Virus infection. West Nile virus is a viral disease that affects horses’ neurological system. The disease is transmitted by mosquito bite. The virus cycles between birds and mosquitoes with horses and humans being incidental hosts. EEE infections in horses are not a significant risk factor for human infection because horses (like humans) are considered to be “dead-end” hosts for the virus.