Health officials are warning the public and offering tips after a batch of mosquitoes tested positive for West Nile virus for the first time this year in Lake County.
A mosquito “pool,” also known as a batch of mosquitoes, was sampled on June 16 in Lake Bluff and tested positive for West Nile virus.
The Lake County Health Department said this mosquito pool is the first confirmed indicator of West Nile virus presence in Lake County in 2021.
“As we approach the summer season, our time outdoors increases, and so does our exposure to mosquitoes,” said Mark Pfister, Executive Director of the Lake County Health Department and Community Health Center.
“Please remember to ‘Fight the Bite’ and protect yourself and your family from mosquitoes that may carry West Nile virus,” Pfister said.
The health department recommends the public practice the “4 Ds of Defense” to protect themselves and family from mosquitoes:
- Drain: Drain standing water from items around your home, yard, and business.
- Defend: When outdoors, use an insect repellent containing DEET, picaridin, oil of lemon eucalyptus, 2-undecanone, or IR3535 and reapply according to label directions.
- Dawn and Dusk: Protect yourself all day and night, and wear repellent outdoors during these prime times for mosquito activity.
- Dress: Wear long sleeves, pants, and closed-toe shoes when outdoors to cover your skin.
Culex pipiens mosquitoes, which are the primary carriers of West Nile virus, are most abundant when the weather is hot.
Residents can help prevent these mosquitoes from breeding by eliminating areas of stagnant water from their properties. Items like buckets, gutters and plant containers, kiddie pools, and any other items holding water around homes and businesses can become breeding sites.
The Lake County Health Department’s Mosquito Surveillance Program coordinates mosquito trapping results throughout Lake County.
Mosquitoes are tested weekly for West Nile virus. The program also monitors reports of dead birds, which can be an early sign of the presence of the virus, and investigates areas of stagnant water for the presence of mosquito larvae, specifically from the Culex mosquito.
“While the hot, dry weather results in fewer mosquitoes overall, the Culex mosquitoes that cause West Nile virus are still present,” said Michael Adam, Deputy Director of Environmental Health at the Lake County Health Department.
“The years with the most cases of West Nile virus have often been during hot, dry summers,” Adam said.
In 2020, 93 pools or batches of mosquitoes tested positive for West Nile virus. Since 2002, there have been 73 confirmed human cases of West Nile virus in Lake County as well as four confirmed deaths.
Most people infected with West Nile virus have no symptoms of illness. However, some may become ill usually 3-15 days after the bite of an infected mosquito, the health department said.
Common symptoms include fever, nausea, headache and muscle ache. In some individuals, severe illness including meningitis or encephalitis, or even death, can occur.
People older than 50 and individuals with weakened immune systems are at higher risk for severe illness from West Nile virus.
Residents can also call the health department’s West Nile hotline to report areas of stagnant water, locations of dead birds, and obtain more information on the signs and symptoms of West Nile virus.
The West Nile hotline number is 847-377-8300.