Encephalitis Killing Horses in Polk, Poses Serious Threat to Humans

Two horses have died in Polk County's Green Swamp area from Eastern equine encephalitis, a mosquito-transmitted illness. The horses reportedly did not have EEE vaccinations. At this time, there have been no reported or confirmed mosquito-borne diseases in humans in Polk County.

According to the Centers for Disease Control (CDC) Eastern equine encephalitis (EEE) virus is "spread to people by the bite of an infected mosquito. Only a few cases are reported in the United States each year. Most cases occur in eastern or Gulf Coast states. Although rare, EEE is very serious. Approximately 30% of people with EEE die and many survivors have ongoing neurologic problems."

Only nine cases affecting humans have been reported in Florida between 2012 and 2021, according to the CDC.

Polk County will be responding today with aerial application of adulticide and larvicide to reduce the populations of mosquitoes in the affected area.

"We've only seen this in the Green Swamp area right now," said Dr. Jackson Mosley, interim manager of Polk County's Mosquito Control Program. "We have not seen it in the Southern portion of the county yet, but people throughout the county should take precautions. Eastern equine encephalitis transmission cycle involves wild birds and specific mosquitoes. Humans and horses are not part of the transmission cycle. However, if infected, they can become seriously ill."

To avoid being bitten by mosquitoes and to limit exposure, residents and visitors are reminded to "Drain and Cover":

• Drain standing water to stop mosquitoes from multiplying.

• Drain water from garbage cans, house gutters, buckets, pool covers, coolers, toys and flowerpots or any other containers where sprinkler or rainwater has collected.

• Discard old tires, drums, bottles, cans, pots and pans, broken appliances and other items that aren't being used.

• Empty and clean birdbaths and pet's water bowls at least twice a week.

• Protect boats and vehicles from rain with tarps that don't accumulate water.

• Maintain swimming pools in good condition and appropriately chlorinated. Empty plastic swimming pools when not in use.

• Cover skin with clothing or repellent.

• Wear shoes, socks, and long pants and long sleeves. This type of protection may be necessary for people who must work in areas where mosquitoes are present.

• Apply mosquito repellent to bare skin and clothing.

• Always use repellents according to the label directions. Repellents with DEET, picaridin, oil of lemon eucalyptus, para-menthane-diol, 2-undecanone and IR3535 are effective.

• Use mosquito netting to protect children younger than 2 months old.

• Cover doors and windows with screens to keep mosquitoes out of your house.

• Repair broken screening on windows, doors, porches, and patios.

Here are some tips on repellent use:

• Always read label directions carefully for the approved usage before you apply a repellent. Some repellents are not suitable for children.

• Products with concentrations of up to 30 percent DEET (N, N-diethyl-m-toluamide) are generally recommended. • Other U.S. Environmental Protection Agency-approved repellents contain picaridin, oil of lemon eucalyptus, para-menthane-diol, 2-undecanone or IR3535. These products are generally available at local pharmacies. Look for active ingredients to be listed on the product label.

• Apply insect repellent to exposed skin, or onto clothing, but not under clothing.

• In protecting children, read label instructions to be sure the repellent is age appropriate.

According to the Centers for Disease Control and Prevention (CDC), mosquito repellents containing oil of lemon eucalyptus or para-menthane-diol should not be used on children under the age of three years. DEET is not recommended on children younger than two months old.

Avoid applying repellents to the hands of children. Adults should apply repellent first to their own hands and then transfer it to the child's skin and clothing.

If additional protection is necessary, apply a permethrin repellent directly to your clothing.

Should you have any questions or concerns about aerial spraying please contact Polk County Mosquito Control at (863) 534-7377.