The Illinois Department of Public Health (IDPH) has confirmed the first human West Nile virus case reported in Illinois for 2015. The St. Clair County Health Department reported an adolescent female became ill in August.
“The recent hot, dry weather in Illinois has increased the number of mosquitoes carrying West Nile virus,” said Illinois Department of Public Health Nirav D. Shah, M.D., J.D. “This first human case is a little later in the year than we typically see in Illinois, but it’s a good reminder of the importance for people to continue taking precautions like wearing insect repellent and staying indoors between dusk and dawn.”
West Nile virus is transmitted through the bite of a 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. However, four out of five people infected with West Nile virus will not show any symptoms. In rare cases, severe illness, including meningitis or encephalitis, or even death, can occur. People older than 50 and immunocompromised individuals are at higher risk for severe illness from West Nile virus.
Environmental and human surveillance for West Nile virus in Illinois includes laboratory tests on mosquito batches, dead crows, blue jays, robins and other perching birds, as well as testing sick horses and humans with West Nile virus-like symptoms. People who observe a sick or dying crow, blue jay, robin or other perching bird should contact their local health department, which will determine if the bird will be picked up for testing.
On May 26, 2015, St. Clair County Health Department staff collected the first West Nile virus positive mosquito batch for the year. The first West Nile virus positive results in 2014 were a positive bird in Henry County collected on May 29, 2014, and a positive mosquito batch in Madison County collected on May 30, 2014. Last year, 50 counties in Illinois reported a West Nile virus positive mosquito batch, bird and/or human case. For the 2014 season, IDPH reported 44 human cases (although human cases are underreported), including four deaths.
Although only one human case of West Nile virus has been reported so far in Illinois, West Nile virus may be circulating in your community. There are simple precautions you can take to reduce the number of mosquitoes around your home and protect yourself from being bitten. Precautions include practicing the three “R’s” – reduce, repel, and report.
- REDUCE exposure – minimize being outdoors when mosquitoes are most active, especially between dusk and dawn. If you go outside during these times, take precautions. Even if mosquito numbers seem low, it only takes one bite from an infected mosquito to transmit the virus.
- Make sure doors and windows have tight-fitting screens. Repair or replace screens that have tears or other openings. Try to keep doors and windows shut, especially at night.
- Eliminate all sources of standing water where mosquitoes can breed, such as old tires, buckets and other receptacles, or refresh the water in bird baths, flowerpots and wading pools every couple days.
- REPEL – when outdoors, wear shoes and socks, long pants and a long-sleeved shirt, and apply insect repellent that contains DEET, picaridin, oil of lemon eucalyptus or IR 3535, according to label instructions. Consult a physician before using repellents on infants.
- REPORT – report dead birds to your local health department. In communities where there are organized mosquito control programs, contact your municipal government about areas of stagnant water in roadside ditches, flooded yards, and similar locations that may produce mosquitoes.