West Nile virus season surveillance begins in Winnebago County
Summer is around the corner, and temperatures are heating up, which may result in the amplification of West Nile virus (WNV) in northern Illinois. Above normal temperatures can increase the rate of Culex mosquito production, mosquito flight activity and virus replication, thereby increasing the proportion of birds and mosquitoes infected with WNV and the risk of disease to humans.
Winnebago County Health Department (WCHD) officials remind residents that it’s just a matter of time before West Nile virus surfaces in our county. As you head out this summer, it is important to take precautions to protect yourself and your family to reduce the risk of being bitten by an infected mosquito.
Above-normal temperatures can increase the rate of Culex mosquito production, mosquito flight activity and virus replication, thereby increasing the proportion of birds and mosquitoes infected with WNV and the risk of disease to humans.
The best way to prevent West Nile virus — or any other mosquito-borne illness — is to reduce the number of mosquitoes around your home and to take personal precautions to avoid mosquito bites. Precautions include practicing the three “Rs” — reduce, repel and report.
• Reduce exposure — Avoid being outdoors when mosquitoes are most active, especially between dusk and dawn.
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, including water in bird baths, ponds, flowerpots, wading pools, old tires and any other receptacles.
• 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 — “Every WNV season, the Winnebago County Health Department offers a phone line for residents to report the location of recently expired birds,” said Winnebago County WNV Program Manager Todd Marshall. “The report line number to call is (815) 720-4245. After calling in a report of a dead bird, you can dispose of the bird yourself, or leave it where it lay, if not picked up for testing within 24 hours of your call.” When calling the hotline to report dead birds, leave the address, town, ZIP code, type and number of dead birds found.
Dead birds cannot spread West Nile virus, but it is advised to avoid barehanded contact with dead birds and other animals since they carry a variety of germs. “Use a shovel, gloves or double-plastic bags to place the carcass in a garbage bag or can,” Marshall added. The Health Department has also opened a West Nile virus Information line for residents who have questions or wish to speak to a health professional. That number is (815) 720-4240.
WNV is transmitted through the bite of a mosquito that has picked up the virus by feeding on an infected bird. West Nile virus is an infection that can cause serious illness, but most people infected with WNV have no signs or symptoms of illness. Most people with the virus have no clinical symptoms of illness, but some may become ill three to 15 days after the bite of an infected mosquito. Those with mild symptoms may have a fever, headache, body aches, skin rash or swollen lymph glands, but those with serious symptoms such as encephalitis and meningitis should seek medical help right away, as death can possibly occur. People at the highest risk for serious illness are those 50 years of age or older.
Based on nationwide experience in Illinois over the previous 11 years of WNV presence in the United States, the peak period for WNV transmission, particularly to humans, has been from mid-July through the middle of October.
In the summer of 2013, Winnebago County Health Department received 315 calls from the general public with questions about West Nile virus and dead bird reports. Those calls resulted in 113 birds tested, with nine being confirmed as positive. One-hundred forty-six mosquito pools were collected, with 13 testing positive with WNV. One confirmed human case of West Nile virus was reported.
From the June 4-10, 2014, issue