St. Louis Encephalitis case confirmed in Duval County

Case marks first in Florida since 2003

JACKSONVILLE, Fla. – A human case of St. Louis Encephalitis has been confirmed in Duval County, and there is a heightened concern additional residents will become ill, according to the Florida Department of Health in Duval County.

The victim, a 58-year-old woman, was tested in late August and the case was recently confirmed. She has since fully recovered.

This is the first reported case of St. Louis Encephalitis in Florida since 2003. Symptoms are similar to those for the West Nile virus, including fever, headache, fatigue, dizziness, weakness and confusion. Most people have no symptoms.

Once someone is bitten by a mosquito infected with St. Louis Encephalitis, it may take five to 15 days for that person to begin to experience symptoms.

With cooler temperatures at night, some might think mosquito season has come to an end. But that's not really the case until December, according to entomologist Marah Clark.

Clark said a sentinel chicken tested positive for the mosquito-borne virus earlier this year, and officials immediately started treating the unidentified area with a mosquito fog. Clark said of the 47 mosquito species in Jacksonville, only one carries St. Louis Encephalitis, which in rare cases can be fatal for babies and the elderly.

"It's something we've always been looking for," Clark said. "Just because we haven't found it doesn't mean it's not out there."

Health officials advise the public to remain diligent in their personal mosquito protection efforts by remembering to "Drain and Cover."

Drain standing water to stop mosquitoes from multiplying.

  • Drain water from garbage cans, house gutters, buckets, pool covers, coolers, toys, flower pots or any other containers where sprinkler or rain water 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 pets' water bowls at least once or 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.

  • Clothing -- 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.
  • Repellent -- Apply mosquito repellent to bare skin and clothing. Always use repellents according to the label. Repellents with DEET, picaridin, oil of lemon eucalyptus, 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.

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 are generally recommended. Other U.S. Environmental Protection Agency-approved repellents contain picaridin, oil of lemon eucalyptus, 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 CDC, mosquito repellents containing oil of lemon eucalyptus should not be used on children under the age of 3. DEET is not recommended on children younger than 2 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. Again, always follow the manufacturer's directions.

Cover doors and windows with screens to keep mosquitoes out of your house. Repair broken screening on windows, doors, porches and patios.

For more information on what repellent is right for you, consider using the Environmental Protection Agency search tool to help you choose skin-applied repellent products.

The Department of Health continues to conduct statewide surveillance for mosquito-borne illnesses, including West Nile virus infections, Eastern equine encephalitis, St. Louis encephalitis, malaria and dengue. Residents of Florida are encouraged to report dead birds via the website for Surveillance of Wild-bird Die-offs. For more information, visit DOH's website or call the Duval County Health Department at 904-253-1850.