Use Your Birding Skills to Help Out With the Cook County West Nile Virus Study

Why did West Nile virus spread so quickly in 2002, especially in Illinois, which led the nation in incidences of the virus and associated deaths? What will happen in future years? How do birds that carry the virus affect its spread?

You are invited to join the University of Illinois, Chicago, the Audubon Chicago Region and the Bird Conservation Network (BCN) in a collaborative, three-year study of West Nile virus to answer these and other questions. Birders are needed to work with University of Illinois researchers to help determine whether there are differences in bird species composition between West Nile virus hot spots and other areas.

Mosquitoes are the major carriers of the virus, and they can get it by feeding on the blood of infected birds. The collaborative study will pull together layers of data on mosquitoes, demographics and landscape features as well as birds, in order to model the spread of the disease. The bird population census is crucial to understanding the role of birds in disease transmission and to better protect both birds and people from West Nile virus.

Birders who can recognize the birds of urban and suburban landscapes by sight and sound are needed during June and early July to count birds along pre-set driving routes in Cook County, including a number of routes in Chicago. If you are not quite sure about your bird song identification abilities, we will provide a CD of bird songs for you to learn. For more information or to volunteer, please contact Judy Pollock at jpollock@audubon.org, or call 847/965-1150.

About West Nile Virus

According to the Chicago Department of Public Health (CDPH), the Northern House mosquito, Culex pipiens, is the primary carrier of West Nile virus. This mosquito species thrives in water with high organic content, such as water found in storm sewers. Hot, dry summers significantly increase the risk of West Nile virus infection, which is counterintuitive to what most people believe. The large swarms of mosquitoes that appear after heavy rains are definitely a nuisance, but they rarely are infected with West Nile virus.

In 2002 some 4,156 human cases (284 of them fatal) of West Nile-related illness were reported nationally. Illinois led the nation with 884 reported cases of West Nile Virus and 67 deaths. In Chicago there were 225 reported cases and 22 deaths. Human case numbers fell off dramatically in 2003, with just four reported illnesses and no fatalities in Chicago. In 2004 there were six cases (one fatal) in the city. In 2005, there were four reported human cases of West Nile-related illness in the state.

The West Nile virus can infect humans, birds, mosquitoes, horses, and some other mammals. In 1999, the virus occurred in the Western hemisphere for the first time, with the first cases reported in New York City. Since then, West Nile virus has been considered an emerging infectious disease in the United States, and has spread down the East Coast to many southern and Midwestern states.

West Nile virus occurs in late summer and early fall in temperate zones, but can occur year-round in southern climates. Usually, the West Nile virus causes mild, flu-like symptoms, called West Nile fever. However, the virus can cause life-threatening illnesses such as encephalitis (inflammation of the brain), meningitis (inflammation of the lining of the brain and spinal cord), or meningoencephalitis (inflammation of the brain and its surrounding membrane). People of all ages are susceptible to West Nile infection, but people over age 50 are at greater risk of developing severe illness.

Preventing West Nile Virus

CDPH officials ask all Chicagoans to take precautions to protect themselves and their families from mosquito bites. Especially important is the use of insect repellant containing DEET (N, N-diethyl-meta-toluamide), Picaridin (KBR 3023) or Oil of Lemon eucalyptus (PMD).

An example of a product containing Picaridin is Cutter Advanced Insect Repellent, available at stores across the city.

In addition to using insect repellant to avoid bites, CDPH officials advise:

• Consider limiting outdoor activity after dark (dusk to dawn), which is when the Northern House mosquito is most active.
• When outside between dusk and dawn, wear loose-fitting, light-colored clothing that includes long pants, long-sleeved shirts, socks and shoes.
• Check to see that all screens on doors and windows are tight-fitting and free of holes and tears.
• Encourage neighbors to exercise precautions.
• To limit mosquito breeding opportunities, CDPH officials recommend:
• Draining and replacing water in birdbaths and children's backyard wading pools every four to five days.
• Properly disposing of old tires, jars, cans, pans, bottles, buckets and other unwanted containers that can hold standing water.
• Making sure that rain gutters, downspouts, swimming pools and pool covers are free of standing water.
• Keeping grass and weeds cut short to eliminate hiding places for adult mosquitoes.