News Local

Health unit battle against West Nile soon to begin

By Ian McInroy, Barrie Examiner

Simcoe Muskoka District Health Unit says there is a chance some mosquitos might carry the West Nile virus this summer. The health unit is advising residents avoid contact with mosquitos.
Supplied photo

Simcoe Muskoka District Health Unit says there is a chance some mosquitos might carry the West Nile virus this summer. The health unit is advising residents avoid contact with mosquitos. Supplied photo

Beware of the bite.

The Simcoe Muskoka District Health Unit will soon be ramping up its efforts to combat mosquitos carrying the West Nile virus.

Human infections from the virus are rare and those affected usually experience only mild symptoms such as fever or headaches. But the illness can be serious and inflammation of the brain (encephalitis) can occur in a small number of cases.

Flu-like symptoms begin in humans about three to 14 days after a bite from an infected mosquito.

Although most people will not become sick if bitten by an infected mosquito, West Nile can cause severe illness in some people. Those at greatest risk of severe illness are people over the age of 50 and people with chronic diseases or weakened immune systems, according to Marina Whelan, program manager in the health unit’s environmental health department.

“This is the stage of the season when mosquitos are starting to breed so this is a really good time to eliminate those mosquito-breeding sites around the home,” she said.

Those sites can include any container, depression or area containing stagnant water for a period longer than seven days in which mosquito eggs may be able to develop to maturity. Other sites include rain barrels, ponds, bird baths, pool and boat covers, and old tires and lawn ornaments.

“What we’re trying to do is prevent the buildup of a large mosquito population. We’ve had a lot of rain so far this spring and there is still a lot of water out there,” she said. “Catch basins (along roadways) are the prime habitat for mosquitos we’re most concerned about.

“There’s water in there. There’s organics in there,” Whelan added. “The bottom of a catch basin gets to be a nice temperature for them. It’s a particular habitat mosquitos like.”

There was one confirmed human case of West Nile in the health unit’s area last year.

“An important point is while there are mosquitos around, people have to remember that we have more than 50 species of mosquitos in Ontario and only about a dozen of those are capable of carrying West Nile,” she said. “But it’s always wise to take precautions. The risk increases as the summer goes along.”

As it gets hotter, the pesky insects’ life cycles shorten, so there is more opportunity for the virus to multiply faster, Whelan said, adding the health unit will be starting its surveillance program next week.

“That consists of checking catch basins and storm ponds and other natural areas for mosquito larvae. We’ll also begin our adult mosquito trapping (to look for the virus) next week,” she said. “The municipalities that are larviciding would likely be starting that at the beginning of July.”

Whelan said people should try to stay indoors when mosquitoes are most active from dusk to dawn.

“When you do go outside, wear light-coloured, long-sleeved shirts, long pants and use a repellent,” she said. “When using insect repellent, be sure to follow the manufacturer’s recommendations. Do not use repellent underneath clothing.”

Visit www.simcoemuskokahealth.org to learn more about West Nile.

imcinroy@postmedia.com