Prairie State Wire

The Illinois Department of Public Health (IDPH) has confirmed the first two batches of mosquitoes to test positive for West Nile virus in 2024. The findings were made in Hoffman Estates in Cook County and Morgan County. The Northwest Mosquito Abatement District collected the specimen from Hoffman Estates on May 14, while the second batch was found on May 16 in Jacksonville, Morgan County.

This confirmation comes two weeks earlier than last year, following a mild winter and spring. IDPH had also reported that the first bird to test positive for West Nile virus was discovered on April 2 in Douglas County.

“The report of the first two batches to test positive for West Nile virus serves as a timely reminder for Illinoisans to begin protecting themselves from vector-borne diseases,” said IDPH Director Dr. Sameer Vohra. He emphasized the importance of reducing exposure to mosquitoes, particularly for older people and those with weakened immune systems.

West Nile virus is transmitted through mosquito bites, typically by house mosquitoes that have fed on an infected bird. Symptoms may include fever, nausea, headache, and muscle aches lasting a few days to weeks. However, most infected individuals show no symptoms at all. In rare cases, severe illnesses such as meningitis or encephalitis can occur leading to death.

In 2023, 67 Illinois counties reported a West Nile virus positive mosquito batch, bird, horse, or human case — an increase from 44 counties in 2022. There were also 119 human cases and six deaths due to West Nile virus last year compared to 33 human cases and seven deaths in 2022 according to provisional data from IDPH.

The department encourages residents to practice the three “R’s” – reduce exposure by ensuring doors and windows have tight-fitting screens; repel mosquitoes by wearing appropriate clothing and using EPA-registered insect repellents; and report stagnant water sources which could breed mosquitoes to local health departments.

More information and data can be found on IDPH’s West Nile virus website and the West Nile virus Dashboard.