Mosquitoes test positive for West Nile virus in Lake County

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LCHD 2017

For Immediate Release
Date: July 21, 2017
Contact: Hannah Goering
(847) 377-8099

Mosquitoes test positive for West Nile virus in Lake County

Waukegan, Ill. – A mosquito pool (batch of mosquitoes) sampled on July 14 in Zion, Illinois has tested positive for West Nile virus. The mosquito pool is the first confirmed indicator of West Nile presence in Lake County in 2017.

“In 2016, there were two human cases of West Nile virus confirmed in Lake County,” said Mark Pfister, Executive Director for the Lake County Health Department and Community Health Center. “Hot weather and standing water create the ideal conditions for mosquitoes to breed. Residents need to take action to protect themselves from mosquito bites.”

“Floodwater mosquitoes are now hatching in the area,” said Michael Adam, Senior Biologist for the health department. “These aggressive biters are reaching nuisance population levels in the county, but do not carry West Nile Virus. A greater concern is that standing water – in items like buckets, gutters and plant containers, debris from flood cleanup, and any other items holding water around homes and businesses – can become breeding sites for Culex mosquitoes, which are the primary carriers of West Nile. We need everyone to eliminate stagnant water from their properties to keep these mosquitoes at bay.”

The Lake County Health Department’s Mosquito Surveillance Program collects mosquitoes in traps around Lake County and tests them weekly for West Nile virus. In 2016, 153 pools or batches of mosquitoes and two birds tested positive for West Nile virus. Since 2002, there have been 58 confirmed human cases of West Nile virus in Lake County, as well as two confirmed deaths. The program also monitors reports of dead birds (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.

Most people infected with West Nile virus have no symptoms of illness. However, some may become ill usually three to 15 days after the bite of an infected mosquito. 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.

Remember to practice the “4 Ds of Defense” to protect yourself and your family from mosquitoes:

  • Drain items that collect standing water, such as bird baths, gutters, plant containers, and buckets from around your yard and business.
  • Defend yourself by wearing insect repellent containing DEET.
  • Dawn to Dusk: Be extra cautious during these peak hours of mosquito activity.
  • Dress with long sleeves, pants, and closed-toe shoes to cover skin.

Find more prevention tips and information on West Nile virus at Residents can also call the Health Department’s West Nile hotline to report areas of stagnant water, report 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.


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LCHD logo 2017

Lake County Health Department
3010 Grand Avenue
Waukegan, Illinois 60085
(847) 377-8000