CHICAGO, IL (Chambana Today) – The Illinois Department of Public Health (IDPH) has announced the first human case of West Nile virus (WNV) in Illinois for 2024. This mosquito-borne illness has been detected in a person in their 60s living in suburban Cook County, with symptoms starting in mid-June. While commercial testing and clinical symptoms indicate WNV, the IDPH has sent the case to the CDC for confirmatory testing, which is still pending.

Tracking West Nile Virus in Illinois

IDPH is actively monitoring positive batches of birds and mosquitoes through its West Nile virus dashboard. So far, 33 counties in Illinois have reported positive results, serving as an early warning of WNV presence in these areas.

Summer mosquito season requires vigilance

“Summer in Illinois means mosquitos, and these mosquitos increase our risk of contracting vector-borne illnesses like West Nile Virus,” said IDPH Director Dr. Sameer Vohra. “We encourage all Illinois residents to ‘Fight the Bite’ and protect themselves and their loved ones from insect bites that can cause potentially serious illnesses.”

West Nile Virus statistics

In 2023, Illinois reported 119 human cases of WNV, a significant increase from 34 cases in 2022. There were six deaths attributed to WNV in 2023, compared to seven in 2022. The first human case in 2023 occurred in late June.

State support for mosquito control

IDPH is backing mosquito control efforts across the state with $2.8 million in funding for the 97 local health departments. This funding supports vector surveillance and control activities, including purchasing and applying larvicide, collaborating with local governments and media for WNV prevention and education, and investigating mosquito production sites and complaints. Local health departments also collect mosquitoes and sick or dead birds for WNV testing.

Understanding West Nile Virus

West Nile virus is transmitted through the bite of a Culex mosquito, which becomes infected after feeding on an infected bird. Common symptoms include fever, nausea, headache, and muscle aches, lasting from a few days to a few weeks. Four out of five people infected with WNV will not show any symptoms. However, severe illness can occur in rare cases, including brain infections like meningitis or encephalitis, paralysis, or even death. People over 50 and those with weakened immune systems are at higher risk for severe illness.

|RELATED: West Nile Virus detected in Champaign County

Prevention is key

There is no specific treatment or vaccine for WNV, making prevention crucial. IDPH encourages the public to Fight the Bite by practicing the three “Rs” – reduce, repel, and report:

  • REDUCE – Ensure doors and windows have tight-fitting screens. Repair or replace any damaged screens. Keep doors and windows shut. Eliminate or refresh all sources of standing water weekly, including bird baths, ponds, flowerpots, wading pools, old tires, and other containers.
  • REPEL – When outdoors, wear shoes and socks, long pants, and a light-colored, long-sleeved shirt. Apply an EPA-registered insect repellent containing DEET, picaridin, oil of lemon eucalyptus, or IR 3535 according to label instructions. Note that the CDC does not recommend products containing oil of lemon eucalyptus or para-menthane-diol for children under 3 years old. Consult a physician before using repellents on young children.
  • REPORT – Report locations with stagnant water sitting for more than a week, such as roadside ditches and flooded yards. Local health departments or city governments may add larvicide to the water to kill mosquito larvae.
Occurrence in Champaign County

Earlier this month, the  Champaign-Urbana Public Health District has reported the detection of West Nile Virus in the local bird and mosquito populations via testing.

Surveillance and reporting

Surveillance for West Nile virus in Illinois involves reporting and investigating individuals with WNV symptoms and conducting clinical laboratory testing. Environmental surveillance includes testing mosquito batches, dead birds, and sick horses. If you observe a sick or dying bird, contact your local health department to determine if it will be picked up for testing.

For more information and data on WNV in Illinois, visit the West Nile virus page.