The LaSalle County Health Department received confirmation that mosquitoes from Ottawa tested positive for West Nile virus.

Researchers collected mosquitos on Friday and conducted the test at the health department. West Nile Virus was also found in Utica, La Salle and Marseilles within the last month.

The La Salle County Health Department said in a Friday news release that West Nile virus is transmitted through the bite of Culex mosquitoes, commonly called a house mosquito, that 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. Most people infected with West Nile virus will not show any symptoms; however, in rare cases it can lead to severe illness including meningitis or encephalitis, or even death. People older than 60 and individuals with weakened immune systems are at 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 see 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.

Residents are asked to make sure doors and windows have tight-fitting screens, and they should repair or replace those that have tears in the openings. Keep windows shut when possible. When outdoors, where shoes and socks, long-pants and a light-colored, long-sleeved shirt and apply an EPA-registered insect repellent.

Residents should also report locations they see sitting water that’s stagnant for more than a week, like roadside ditches, flooded yards, pools or similar locations.

A complete listing of West Nile virus statistics for LaSalle County is available on the Health Department’s web site at www.lasallecountyil.govunder Environmental Health/Vector Control. A state-wide listing is available at the Illinois Department of Public Health’s web site at https://dph.illinois.gov/topics-services/diseases-and-conditions/west-nile-virus/surveillance.