May 31, 2004

First bird tests positive for West Nile virus

NEWMARKET: York Region Health Services reports that a dead crow has tested positive for West Nile virus (WNv ). The dead crow was found in the Town of Aurora, close to the intersection of St. John's Sideroad and Industrial Parkway. The bird is the first positive bird reported in York Region this season.
Like humans, West Nile virus is transmitted to the bird population by infected mosquitoes. Crows, blue jays and other raptor species are known to be most susceptible to the disease and act as early warning signs for the presence of the virus in a particular area.
Last season, the first dead crow that was tested and presumed positive for West Nile virus was found in the Town of Newmarket on April 15, 2003. It was picked up through the West Nile virus surveillance program and was the first positive bird reported in Canada in 2003.
Despite this early activity, there were a relatively low number of cases reported, with 2 human cases, 9 birds and 6 mosquito pools testing positive for the virus in York Region in 2003. The Ministry of Health and Long-Term Care attributed 2 deaths in the province last year to West Nile virus illness, with no deaths in York Region.
Report dead crows and blue jays
York Region Health Services requests that residents report sightings of dead crows and blue jays. Suitable specimens may be collected and submitted to the Canadian Co-operative Wildlife Health Centre in Guelph for testing. All crows and blue jays that are reported will help to map out possible West Nile virus activity in York Region.
Dead crows and blue jays are to be reported to York Region Health Services through the Health Connection information line at 1-800-361-5653.
 Suitable specimens - A suitable specimen must be a crow or blue jay that has died less than 12 hours prior to collection. These birds may be collected by York Region Health Services and sent for testing.
 Unsuitable specimens Most dead birds will not be suitable for testing, but knowing what species they are and where they died is important information. Do not handle birds with bare hands or dispose of dead birds through the municipal garbage systems. If you choose to handle a dead bird, wear rubber gloves, double bag the bird and contact Health Connection for pick-up.
 Dead bird pick-up service is available - Please contact Health Connection for pickup of dead birds of any species.
 (West Nile virus bird surveillance program continued)
To date, York Region Health Services has picked up 105 dead birds, with seven of those suitable and submitted for testing for West Nile virus.
West Nile virus is a mosquito-borne virus that can in rare cases cause serious illness. The risk of
becoming seriously ill as a result of infection with West Nile virus is low and most people who become infected experience no symptoms or have very mild illness. The virus is named after the West Nile region of Uganda where it first appeared in 1937.
The chances of being bitten by an infected mosquito are rare. In fact, for the very few who are bitten by an infected mosquito most do not even know it, with approximately four out of five people infected by West Nile virus not showing any symptoms or signs of illness at all.
The symptoms for West Nile virus illness consist of fever, muscle weakness, stiff neck, confusion, severe headache, and a sudden sensitivity to light. For a very rare few, the virus causes serious neurological illness including encephalitis (inflammation of the brain).
See the attached Fact Sheet on York Region's 2004 West Nile virus Control Plan and simple, common sense precautions that should be taken.
To report a dead crow or blue jay and for more information on West Nile virus or any health-related concern, contact York Region Health Services Health Connection at 1-800-361-5653 or visit

Fact Sheet

York Region's 2004 West Nile virus (WNv) Control Plan
The York Region West Nile virus (WNv) control plan for 2004 includes:
 Mosquito, bird and human surveillance
 WNv control activities, including a larviciding strategy:
- The first larvicide application will be in June and the subsequent applications will be in July, August and September. These applications will target all catch basins in Richmond Hill, Vaughan, Markham, Aurora, Keswick and Holland Landing and other urban areas with catch basins
- In addition, any newly identified positive bird, mosquito and human cases in 2004 will be mapped and larvicide will be applied in the catch basins around those newly detected positives
- Methoprene is the larvicide that will be used. It comes in a slow-release pellet-like formulation and is administered in catch basins when the mosquito is in the larval stage of development. It is not sprayed. It has been approved by both the provincial and federal governments and is considered low risk for humans and the environment when it is applied according to label directions
 The WNv control plan also includes public education regarding common sense and effective measures to prevent exposure to WNv, including brochures, posters, public information sessions and community outreach activities.
Prevention and protection are the best ways to protect yourself and your family from WNv. There are simple and common sense precautions that should be taken:
 Minimize outdoor activities where and when mosquitoes are most active such as dusk, night and dawn
 Wear protective clothing such as long sleeved shirts, full-length trousers, socks, light coloured clothing and tuck pant legs into socks when possible.
 Consider using an insect repellent, as directed
 Make sure screens on your home are tight-fitting and in good repair
 Mosquitoes breed in still water. Eliminate stagnant water around your property which may gather in pool covers, flower pots, children's pools, old tires and birdbaths
Media Contact: Wendy Lewis, York Region Corporate Communications Services
   905-830-4444 or 1-877-464-9675, Ext. 1238


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

Back to top