August 1, 2010

Mosquito-borne viruses that can affect horses and people have surged in Florida, with an infant dying from Eastern Equine Encephalitis (EEE).

Monitoring across Florida has confirmed two horses have been infected with West Nile Virus and 60 horses have become infected with EEE across two dozen counties.

Monroe County is already under a mosquito-borne illness alert, and has now been joined by Hillsborough County following the infant's death.

Volusia, Walton, Glades, Collier, Osceola, Miami-Dade, Polk, Lake, Jackson, Madison, and Wakulla counties are under mosquito-borne illness advisories.

The Hillsborough County Health Department said it was advised of the child's death from EEE on Thursday afternoon.

"Losing a child is one of the most difficult experiences any family can endure, and words of true comfort are hard to find," said department director Douglas Holt.

"We offer our deepest condolences to the family for their loss."

It is the second death in Florida attributed to EEE since 2008.

"Since there is no vaccine to help protect people, we hope that area residents will take every precaution possible to prevent being bitten by mosquitoes this season," said Warren McDougle, epidemiology programme manager with the health department.

Surveillance data has indicated a continued rise in transmission activity involving mosquito-borne viruses.

In recent months, five horses in Hillsborough County have tested positive for EEE.

Authorities across Florida are promoting the "five Ds" for prevention:

• Dusk and Dawn - Avoid being outdoors when mosquitoes are seeking blood. For many species, this is during the dusk and dawn hours.

• Dress - Wear clothing that covers most of your skin.

• DEET - When the potential exists for exposure to mosquitoes, repellents containing DEET (N, N-diethyl-meta-toluamide, or N, N-diethyl-3-methylbenzamide) are recommended. Picaridin and oil of lemon eucalyptus are other repellent options.

• Drainage - Check around homes to rid the area of standing water, which is where mosquitoes can lay their eggs.

EEE can cause inflammation of the brain (encephalitis). In the United States, 5-10 cases are reported in people annually.

Most cases ave been reported from Atlantic and Gulf Coast states. Cases have also been reported from the Great Lakes region.

Authorities recommend that horse owners vaccinate their animals against EEE and West Nile.

Agriculture commissioner Charles Bronson noted that cases in horses had been reported in southern counties such as Miami-Dade, Okeechobee and Collier, where EEE cases are normally much less frequent.

Bronson says there are vaccinations for both diseases but horse owners need to be diligent in not only getting their animals vaccinated, but also ensuring the vaccinations are kept up to date each year with booster shots.

"In the vast majority of cases we have seen this year, the horses either had no vaccinations at all or they were not current," Bronson said.

"We are seeing increases in mosquito populations and since mosquitoes are the carriers of both these diseases, it's likely the situation is going to get worse before it gets better.

"I can't stress enough the need for people to get these readily available vaccinations for their horses."

Signs of the viruses in horses include fever, listlessness, stumbling, circling, coma and usually death.

EEE is fatal in horses in 90 per cent of the cases. West Nile virus has a mortality rate in horses of about 30 per cent.

Studies show that in horses that do recover, anywhere from 20-40 percent show residual effects even after six months.