West Nile virus: an urban issue

A few days ago, thanks to Health Department staff, I learned some new and interesting things about mosquitoes and West Nile virus (WNV) that I would like to share with you.

Did you know…

  • There are close to 3000 types of mosquitoes in the world and there are 82 types in Canada?
  • There are only a few types that can transmit WNV to humans? The mosquito that most transmits WNV to humans is called Culex pipiens.
  • Culex pipiens prefers to live where humans live: in urban and suburban areas. It more commonly breeds in water-holding, man-made containers, not in swamps, bogs, or in typical cottage country (Muskoka, Kawartha areas) or northern camping areas.

Because Culex pipiens live in urban areas, Halton residents need to take precautions around the home to prevent mosquito breeding sites and bites even more than when camping or at a cottage.


  • Cover up. Wear light-coloured, long-sleeved shirts and pants with tightly-woven fabric.
  • Avoid being outdoors from early evening to morning when mosquitoes are most active and likely to bite, as well as at any time in shady, wooded areas.
  • Reduce mosquito breeding sites around your home by getting rid of all water-filled containers and objects. Change the water in bird baths at least once per week.
  • Use an approved insect repellent, such as one containing DEET.
  • Make sure your window and door screens are tight and without holes, cuts or other openings.

To help reduce areas where mosquitoes can breed, the Halton Region Health Department will apply larvacide to areas like storm water ponds and catch basins. Visit our West Nile Virus surveillance webpage to see the locations of larvaciding as well as other tracking data.

If you know of an area with standing water you are concerned about, please call Halton Region.

For more information on WNV or to report standing water, dial 311 or call Halton Region at 905-825-6000, toll free 1-866-442-5866, or email accesshalton@halton.ca.

As always, if you have any Regional concerns or comments you would like to share, please feel free to email me at gary.carr@halton.ca. You can also find me on Twitter @garycarrhalton or on Facebook.