May 09, 2002

West Nile Virus surveillance program to start


Newmarket: The West Nile Virus bird surveillance program in York Region will begin effective May 15, 2002. This year the bird of concern is the crow. Crows are known to be the most susceptible to the disease.

West Nile Virus (WNV) is a mosquito-borne virus that can cause encephalitis (inflammation of the brain) or meningitis (inflammation of the lining of the brain and spinal cord). The virus is named after the West Nile region of Uganda where it was first isolated in 1937. It is commonly found in Africa, West Asia and the Middle East.

WNV is transmitted by infected mosquitoes. In humans, it takes about 3 to 12 days after a bite from an infected mosquito for flu-like symptoms to begin. Most people infected will have no symptoms or very mild illness. Symptoms range from mild fever and headache to loss of consciousness, seizures, weakness on one side of the body and swelling of the brain resulting in brain damage. People over 50 years of age have the highest risk for severe symptoms.

WNV is transmitted to the bird population in the same manner. Symptoms in birds manifest as neurological signs such as convulsions, tremors, head tilt, wing droop and paralysis.

WNV was isolated in the bird population within York Region during the 2001 season. The WNV bird surveillance program will help to monitor the prevalence of WNV in the Region this season. There have been no known human cases in Canada, to date.

Dead birds of concern are to be reported to York Region Health Services and suitable specimens will be collected and sent for testing. Unsuitable or birds not of concern should be double bagged and disposed of or buried under at least 2 feet of soil. Do not handle birds with bare hands.

Although the risk of coming into contact with the WNV is minimal, there are precautions that can be taken:

For more information on West Nile Virus or any health-related issue, contact York Region Health Services Health Connection at 1-800-361-5653 or 905-895-8004.

The Regional Municipality of York is committed to providing cost-effective, quality services that respond to the needs of our rapidly growing communities.  York Region is comprised of the following nine area municipalities:  Aurora, East Gwillimbury, Georgina, King, Markham, Newmarket, Richmond Hill, Vaughan and Whitchurch-Stouffville.  For more information, visit our Web site at:

Contact: Patrick Casey, Senior Media Relations Specialist, York Region

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