August 16, 2006
Media Release

First birds test positive for West Nile virus

NEWMARKET – York Region Health Services reports that four dead birds have tested positive for West Nile virus (WNv).  One blue jay was found in the Town of Markham, close to the intersection of Bayview Avenue and Highway 7.  A crow was found in the Town of Aurora, close to the intersection of Yonge Street and Vandorf Sideroad.  Two more crows were also found in the Town of Newmarket, at the intersections of Yonge Street and Eagle Street and Yonge Street and Davis Drive.
The birds were picked up through the WNv surveillance program.  They are the first positive birds reported in York Region this season.
Last year, the first two positive birds in York Region were reported August 8th and were found in the Town of Markham.  In 2005, five human case, 22 birds and 14 mosquito pools tested positive for the virus in York Region.
To date, there has been one reported case of WNv in humans in Ontario in 2006.  None have been reported in York Region.
Like humans, WNv 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.
Report dead crows and blue jays. York Region Health Services requests that residents report sightings of dead crows and blue jays through the Health Connection information line.  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 WNv activity in York Region.
Dead bird pick-up service is available. 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.  Please contact Health Connection for pick-up of dead birds of any species.
The symptoms of WNv illness in humans 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).  Those experiencing symptoms should seek medical advice.
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
The York Region WNv control plan for 2006 includes:
• Mosquito, bird and human surveillance
• WNV control activities, including a larviciding strategy:
• The strategy includes four larvicide applications (in June, July, August and September).  Two larvicide applications have now been completed.  These applications target all catch basins along Regional and Municipal Roads and in catch basins, as required, on private property.
• Methoprene is the larvicide that is 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 interferes with the mosquito life cycle, preventing the mosquito larva from reaching maturity.  It is not sprayed.  It has been approved by both the provincial and federal governments and is considered low risk for humans, pets 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
To report a dead crow or blue jay, and for more information on WNv or any health-related concern, please contact York Region Health Services Health Connection at 1-800-361-5653 or visit
To review the current status of WNv in Ontario, visit
- 30 -
Media Contact: Jennifer Mitchell-Emmerson, York Region Health Services
 Phone:  (905) 830-4444, ext. 4016 or After-hours Pager (905) 830-3302

Contact Information
Back to top