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West Nile Virus & Mosquitos

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Mosquitoes & Disease

Mosquitoes transmit serious and sometimes fatal diseases, such as West Nile Virus, to humans, birds, horses, and other mammals.   

West Nile virus emerged in the United States in the New York metropolitan area in the fall of 1999. Since then, the virus, which can be transmitted to humans by the bite of an infected mosquito, has quickly spread across the country. 

Kendall County began conducting West Nile virus surveillance through the trapping and testing of mosquitoes in 2002.  Our surveillance program has shown that mosquitoes in Kendall County test positive for the West Nile virus every year, indicating the need for continued surveillance and education of our community on mosquito prevention and awareness. 

West Nile virus is transmitted through the bite of an infected Culex mosquito.  Mosquitoes become infected with the West Nile virus when they feed on infected birds and can then transmit the virus through their bite to humans and animals.  The greatest risk for contracting the virus exists in the summer and fall, June through October, and especially when the weather is consistently hot and dry. The West Nile virus is NOT transmitted from person-to-person.  

Most people infected with the West Nile virus experience few if any symptoms and recover completely after only a few days. Mild symptoms include a headache, body aches, swollen lymph glands, and occasionally a skin rash on the trunk of the body. Although rare, some people experience severe infection (West Nile encephalitis or meningitis), with symptoms including headache, high fever, neck stiffness, disorientation, paralysis, coma, and death.  Persons ages 55 or older with preexisting health conditions are more likely to develop severe illness.  

There are no medications to treat or vaccines to prevent West Nile virus infection. People with milder symptoms typically recover on their own, although some symptoms may last for several weeks. In more severe cases, patients often need to be hospitalized to receive supportive treatment, such as intravenous fluids, pain medication, and nursing care. 

 

Protection & Awareness

The best way to prevent West Nile encephalitis and other mosquito-borne illnesses is to reduce the number of mosquitoes around your home and neighborhood and to take personal precautions to avoid mosquito bites.

Remove Standing Water Where Mosquitoes Lay Eggs

  • Once a week, empty and freshen with clear water, turn over, cover, or throw out any items that hold water, like tires, buckets, planters, toys, pools, birdbaths, flowerpot saucers, or trash containers.  
  • Tightly cover water storage containers (buckets, cisterns, rain barrels) so mosquitoes cannot get inside to lay eggs. 
  • Fix leaky faucets 
  • Clean gutters frequently 
  • For containers without lids, use wire mesh with holes smaller than an adult mosquito. 

Kill Mosquito Larvae Outside Your Home

  • Use larvicides to treat large bodies of water that will not be used for drinking and cannot be covered or dumped out.  Examples include ornamental ponds, fountains, and unused pools. 
  • When using larvicides, always follow label instructions as different products are intended for different applications. 

Click here for additional information from the CDC on Mosquito Control.

Protect Yourself from Mosquito Bites

  • Use the Environmental Protection Agency (EPA)-registered insect repellents with one of the active ingredients below. When used as directed, EPA-registered insect repellents are proven safe and effective, even for pregnant and breastfeeding women. 
  • Avoid places and times when mosquitoes bite, especially at dawn and dusk. 
  • Wear light-colored clothing that protects your arms and your legs. 
  • Ensure windows and doors with screens are in good repair and are tight-fitting; repair any tears or holes. 
  • Use mosquito netting around small babies and if sleeping outdoors for protection. 

 

County Surveillance

A mosquito trap with a mesh cover sits in a black basin on the ground next to a bush and a brick wall. A plastic container with batteries is in front of the trap. 

Mosquito Surveillance

The Kendall County Health Department conducts a multi-faceted mosquito surveillance program, trapping and testing Culex mosquitoes for the West Nile Virus. The Environmental Health Services unit sets mosquito traps placed throughout the county from May 1st through October 15th each year, collecting and testing mosquito samples on a weekly basis.  

Click here for Local and State-Wide West Nile Virus Surveillance Data.

Dead Bird Surveillance

The Kendall County Health Department may collect perching birds (not limited to crows, blue jays, robins, grackles, starlings, sparrows) for its West Nile virus surveillance program. These birds are very sensitive to West Nile virus, and they can indicate the presence of West Nile virus in an area. 

Conditions required for dead bird specimens: 

  1. The bird is dead, but the carcass is in good condition. Birds should be dead no more than about 24-48 hours prior to collection, and should not show signs of advanced decomposition (maggots, strong odor, dried or deflated eyes). 
  2. The bird shows no sign that it died of causes other than disease. Birds with obvious injuries, such as wounds or missing parts, or birds that obviously flew into a window, should not be submitted for testing. Likewise, crushed carcasses and birds found along roadways are not acceptable. 
  3. The bird must be acceptable for testing. Some acceptable species are crows, blue jays, grackles, starlings, robins, cardinals, sparrows, finches, hawks, and owls. Birds that will not be accepted include pigeons, ducks, geese, chickens, other large birds, and endangered species.   

To report a dead bird, please call 630-553-8026.

 

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