A dead crow collected in Bracebridge is the first bird to test positive for West Nile virus (WNv) in Simcoe-Muskoka this season.

"This tells us that West Nile virus is in the area and that we need to protect ourselves and our families throughout the remainder of the season," says Marina Whelan, manager of the health hazards program at the Simcoe-Muskoka District Health Unit.

"This is the time of the year when we expect to see the virus, which makes it important that people use insect repellent when they are outdoors and cover up so that they avoid being bitten by mosquitoes."

The health unit has received 522 reports of dead bird sightings and submitted 18 birds to the Canadian Cooperative Wildlife Health Centre in Guelph for testing since it began its dead bird surveillance program in May.

Across Ontario to date, 17 birds have tested positive for the virus.

"Reports of dead birds are an important tool in helping us identify those areas where risk appears to be higher," Whelan says. "We encourage the public to continue to report sightings to us."  

In 2007 there were 912 dead birds reported to the health unit's WNv program. Two tested positive for the virus. There were no human cases in Simcoe-Muskoka last year.

West Nile virus is spread by the bite of mosquitoes that have previously bitten infected birds. People older than 50 and those with chronic disease or weakened immune systems are most at risk but anyone who lives in an area where there are infected mosquitoes can get WNv.

The virus can cause serious illness in some people and, on rare occasions, death.