First birds test positive for West Nile

York Region Health Services reports that four dead birds have tested positive for West Nile virus (WNv).

One jay was found in Markham, close to the intersection of Bayview Avenue and Highway 7. A crow was found in Aurora, close to the intersection of Yonge Street and Vandorf Sideroad. Two more crows were also located in 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 this season.

Previously, a mosquito pool found in the area of Schomberg tested positive for the virus.

Last year, the first two positive birds in York were reported Aug. 8 and were found in Markham. In 2005, five human cases, 22 birds and 14 mosquito pools tested positive for the virus in the region.

To date, there has been one reported case of WNv in humans in Ontario this year, and neither was in York.

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.

Residents are asked to report dead crows and blue jays that they find through the Health Connection information line at 1-800361-5653. 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. Contact the 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.

There are simple and common sense precautions that should be taken to avoid the illness:  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, along with WNv control activities, including a larviciding strategy.

The strategy includes four larvicide applications, and two of those applications have now been completed, according to Health Services. They 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 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 1-800-3615653 or visit www.york.ca