Mosquitoes in Marseilles test positive for West Nile virus

La Salle County Health Department warns residents of possible West Nile activity

Shaw Local file photo – Mosquitoes collected in traps in Sandwich have tested positive for the West Nile virus, the DeKalb County Health Department announced Friday.

The La Salle County Health Department confirmed mosquitoes from Marseilles tested positive for West Nile virus.

The mosquitoes were collected June 2 and environmental health staff conducted the test on the mosquitoes at the health department.

This is the first documented West Nile virus activity in La Salle County this year.

“This is the time of year we expect to see West Nile virus activity increase,” said Jennifer Osborn, director of environmental health. “Mosquitoes will remain active until the first hard frost, so it is important that everyone take precautions to protect themselves from mosquitoes and the viruses they carry.”

In hot, dry weather, mosquitoes that carry West Nile breed in stagnant water and multiply rapidly, Osborn said.

“The best way to protect yourself against illness is to wear insect repellant, especially during the evening hours, and to get rid of any stagnant water around your home to reduce the number of mosquitoes,” Osborn said.

West Nile is transmitted through the bite of a house mosquito, which has picked up the virus by feeding on an infected bird. Common symptoms include fever, nausea, headache and muscle aches. Symptoms may last from a few days to a few weeks. Four out of five people with the West Nile virus will not show any symptoms. IN rare cases, severe illness including meningitis and encephalitis, or even death, can occur. People older than 60 and individuals with weakened immune systems are at a higher risk for severe illness from West Nile virus.

Monitoring for West Nile virus includes laboratory tests for mosquito batches, dead crows, blue jays and robins, as well as testing humans with West Nile virus-like symptoms. People who observe a sick or dying crow, blue jay or robin should contact the health department, which will determine if the bird will be picked up for testing.

Precautions include practicing the three r’s - reduce, repel and report.

Residents should make sure doors and windows have tight-fitting screens and repair screens that have tears or other openings. Try to keep doors and windows shut. Eliminate, or refresh each week, all sources of standing water where mosquitos can breed, including water in bird baths, ponds, flowerpots, pet bowls, clogged rain gutters, wading pools, old tires and any other containers.

Residents should wear shoes and socks, long pants and light-colored, long-sleeved shirts and apply an EPA-registered insect repellant that contains DEET, picaridin, oil of lemon eucalyptus or IR 3535, when outdoors. Consult a physician before using repellants on infants.

Residents also should report locations where there’s sitting stagnant water for more than a week, such as roadside ditches, flooded yards, old tires, stagnant pools and similar locations that may produce mosquitoes. The local health department or city government may be able to add larvicide to the water, which will kill any mosquito larvae.

Go to for more information on West Nile virus in La Salle County.