mosquito.jpgWEST PALM BEACH — The Palm Beach County Health Department has announced that regular monitoring in Palm Beach County at 7 strategically placed sentinel chicken flocks have revealed the presence of St. Louis Encephalitis virus at one site in the western county. No human or other animal infections have been identified.

Residents and visitors are being urged to take simple preventive measures to protect against contracting mosquito-borne illnesses. 

“The sentinel chicken program was first established in 1978 throughout Florida,” said Health Department Veterinarian Mary Echols.

“This early warning system is vital to help make the public aware of the presence of mosquito-borne illnesses and the importance of mosquito-borne disease prevention.” The last positive result for the presence of St. Louis Encephalitis in Palm Beach County was in 2001.


St. Louis Encephalitis virus is a mosquito-borne flavivirus that is maintained in a cycle between Culex mosquitoes and birds. Occasionally, an infected mosquito will bite a human, causing disease. 

Fewer than 1 percent of St. Louis encephalitis viral infections are clinically apparent and the vast majority of infections remain undiagnosed. Symptoms appear 4 to 21 days after the bite of an infected mosquito. 

Most infections are unapparent but when symptoms occur they can range from fever with headache to meningitis, encephalitis, and coma. People over the age of 50 seem to be at greater risk for severe disease.  Anyone suspecting they are sick should contact their physician immediately.

The mosquito population grows in the summer which coincides with the time of year many residents and visitors are outdoors enjoying Florida’s natural landscape. The rainy season can signal an increase in mosquito populations.


Health Department Director Alina Alonso, M.D., encourages basic prevention methods to help limit mosquito bites and exposure to mosquito-borne illness.

“Residents and visitors need to take precautions to prevent mosquito bites and eliminate mosquito friendly breeding places around their homes by remembering to Drain and Cover,” said Health Department Director Alina Alonso, M.D.

• Drain any standing water around your home as even the smallest container can be a breeding ground for mosquitoes

• Check doors and window screens and repair any holes or tears

• Cover yourself with light weight clothing that has long sleeves, wear long pants and socks and use an insect repellant following the manufacturer’s recommendation

• If outdoors at dusk or dawn, be cautious as mosquitoes are most active during these times; however some species of mosquitoes are also active during the day.

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