First Mosquitoes With West Nile Virus Found On North Shore

NORTHFIELD, IL — The first North Shore mosquitoes to test positive for West Nile virus in 2019 were collected last week. Five samples of mosquitoes, collected Monday through Wednesday in Evanston, Glencoe, Glenview, Northbrook and Winnetka, tested positive Thursday for the virus, North Shore Mosquito Abatement District announced.

So far in 2019, 90 batches of mosquitoes have been collected from NSMAD traps. State public health officials announced Friday the first West Niles-positive mosquitoes found in Illinois this year were discovered in DuPage County. Samples were collected Tuesday — the same time as the five batches found on the North Shore.

The risk of human infection with West Nile virus is low at this time of year, but public health officials recommended taking precautions to minimize the risk of mosquito bites. Insect repellant, loose clothing and avoiding peak mosquito hours of dawn and dusk were recommended.

West Nile virus was found in 75 counties in the state last year, according to the Illinois Department of Public Health. There were 176 human cases, and 17 people died as a result of the virus. Symptoms of West Niles infection, including fever, nausea, headache and muscle aches, may last from a few days to a few weeks. Still, four out of five people who contract the virus virus will not show any symptoms, according to IDPH.

Last year, the North Shore Mosquito Abatement District tested 1,705 batches of mosquitoes, detected 581 West Nile-positive samples across the 10 northern Cook County municipalities where it operates. Mosquito abundance was especially high early in the summer, remaining above average until August. The decline was helpful to humans: the mosquito population declined during the period of the season when the risk of human infection was at its highest.

Residents were asked to eliminate any items on their property that can hold water, including smaller items that might be easily overlooked. State public health officials recommended cutting the risk of contracting the virus by reducing the chance for mosquitoes to reproduce, repelling them from areas where humans are present and reporting areas of stagnant water or sick and dying birds to local health departments.

Acting IDPH Director Dr. Ngozi Ezike said in a release that many pools of water from recent rainfall are sitting in backyards, sewers and drains.

"As we start to see higher temperatures, we will start to see more West Nile virus activity," Ezike said. "While we see West Nile virus in Illinois every year, it is important not to become complacent. It's easy to take precautions to protect yourself by wearing insect repellent and getting rid of standing water around your home."

Chicago was recently ranked the nation's fourth worst city for mosquitoes by a pest control company, citing the number of customers calling about mosquitoes between April 2018 and 2019. No human cases of West Nile virus have been reported in 2019.