Ontario city raises West Nile risk after batch of mosquitos test positive

An adult mosquito is shown in a laboratory in the Middlesex-London Health Unit kicked off in Strathroy, Ont. THE CANADIAN PRESS/Dave Chidley

The City of Hamilton is reminding people to be vigilant after a batch of mosquitos recently trapped there tested positive for West Nile virus.

This is the first time this year that the mosquito-bourne illness has been found in the southwestern Ontario city.

As a result, Hamilton’s Medical Officer of Health has made the decision to move its West Nile Virus risk from low to moderate.

Residents are being reminded to protect themselves against mosquito bites by using bug spray containing DEET or Icaridin, avoiding areas where mosquitoes are known to be present, covering up and wearing light coloured long sleeves and long pants when in wooded areas, on the golf course, or in the garden, especially at dawn and dusk when mosquitoes are most active.

Another way to reduce the risk of contracting West Nile Virus is by deterring mosquito breeding. One of the most effective ways to do this is by removing standing water at least weekly from private property, they said.

In a July 29 news release, the City of Hamilton said it “continually assesses the risk for human illness as part of a comprehensive West Nile Virus surveillance and prevention program,” adding they’ve recently completed a second round of larviciding treatments on city street catch basins, in addition to ongoing treatment of surface waters on public land.

An estimated 20 per cent of those who contract West Nile Virus experience fever, while very few people infected – usually older adults or those with weakened immune systems – experience more severe symptoms like inflammation of the brain or the lining of the brain. Most people have no symptoms, which typically appear two to 14 days after being bitten by an infected mosquito.