West
Nile Virus first emerged in the United States in the New York
metropolitan area in the fall of 1999. Since then, the virus, which
can be transmitted to humans by the bite of an infected mosquito,
has quickly spread westward across the country. In Illinois, West
Nile virus was first identified in September 2001 when laboratory
tests confirmed its presence in two dead crows found in the Chicago
metropolitan area.
In 2002, birds, mosquitoes and horses in 100 of the state's 102
counties were reported positive for West Nile virus and the first
human cases and deaths from West Nile virus illness in Illinois
were reported in August 2002. By the end of the year, the state
led the nation with more than 800 human cases and 64 deaths. Thirty-eight
of those deaths were in Chicago and suburban Cook County.
The 2003 season was far more mild with only 12 confirmed human cases
of West Nile Virus in suburban Cook County. However, the unit still
received over 1500 inquiries related to animal and human deaths
and proper prevention methods.
In an effort to continue to answer questions of public concern and
to keep the public safe from West Nile Virus in the future, we continue
to run prevention programming. The Cook County Department of Public
Health Vector Control Program maintains an environmental surveillance
program to monitor dead perching birds.
Mosquito surveillance is maintained by the four
Mosquito Abatement Districts (MAD) serving suburban Cook County.
These are separate taxing bodies that are regulated by the Department
of Agriculture, not the Cook County Department of Public Health.
The districts conduct surveillance to locate and control or eliminate
mosquito breeding sources. The districts serving suburban Cook County
are the Des Plaines Valley Mosquito Abatement District, North
Shore Mosquito Abatement District, Northwest
Mosquito Abatement District and South Cook County Mosquito Abatement
District.
West Nile Virus Frequently Asked Questions
What is West Nile virus?
An infection carried by mosquitoes. People get WNV from the bite of a mosquito that is infected with WNV. Mosquitoes become infected when they feed on a bird that has the virus in its blood. Once infected the mosquito can spread the virus to humans and other animals.
Who can get WNV?
Anybody can become infected with WNV so it's important to protect yourself from mosquito bites. People over the age of 50 and those with chronic diseases such as heart disease or cancer may be more at-risk for serious illness. Most human cases occur in the late summer and early fall.
What are the symptoms?
Most people infected with WNV have no symptoms of illness and never become ill. Some people may become ill 3-15 days after being bitten by an infected mosquito. Symptoms may include fever, headache and body aches. More severe symptoms may be a high fever, stiff neck, confusion and muscle weakness.
Should we stay indoors?
It is not necessary to limit outdoor activities unless there is evidence of mosquito-borne disease in your area. However, you can and should try to reduce the risk of being bitten by mosquitoes.
How can I help protect my family and myself from mosquitoes and the diseases they may carry?
During the summer, mosquitoes can develop in any standing water that lasts more than seven to 10 days. Consequently, you can begin protecting your family from mosquitoes by reducing the amount of standing water available for mosquito breeding around your home:
Empty plastic wading pools weekly or store upside down when not in use.
Change water every few days in bird baths and plant saucers.
Store boats covered or upside down.
Water bowls for pets should be emptied and refilled daily.
Also...
Keep weeds and grass cut short.
Be sure screens in homes are in good repair and tight fitting.
Keep gutters around your home clean and in good repair.
Limit time outdoors when mosquito activity is heaviest (dusk to dawn).
If outside, wear socks, shoes, long pants and a long-sleeved shirt. Loose-fitting, light colored clothing is best.
Use repellents containing 25-35% DEET (N,n-diethyl-meta-toluamide). Always follow label directions. Talk to your doctor before applying repellent to infants or children.
Protect babies and small children by using mosquito netting over strollers.
What if I find a dead bird?
The presence of dead perching birds in a community is a sign of possible WNV in the
area. If you find a dead bird, please
call 708-492-2035 to report your sighting. CCDPH
staff will determine if they need to pick up the bird for laboratory
testing.
What do perching birds look like?
Perching birds are:
