Halton Preparing for Another Season of West Nile Virus

Halton Region is preparing for another season of mosquitoes and the potential for West Nile virus (WNV) infections.

The Health Department’s seasonal program aims to help reduce the risk of human infections of West Nile virus. As in past years, public education about WNV, personal protective measures and how to reduce standing water where mosquitoes breed, and the application of mosquito larvicide to breeding sites such as storm water catch basins and certain natural surface waters will be included in the program.

“About 80% of people who become infected with WNV do not experience any illness, while about 20% will develop West Nile fever,” said Dr. Bob Nosal, Halton Regional Medical Officer of Health. “Less than one percent will develop inflammation of the brain or its lining, or a type of paralysis. Older adults and people with underlying illnesses should be particularly cautious as they are more likely to develop the illness.”

Mosquitoes can transmit WNV to humans after becoming infected by feeding on the blood of birds carrying the virus.

WNV is most of all an urban issue affecting the cities and towns in southern Ontario that have the warmest climates. There are many different kinds of mosquitoes, but only a few types are able to carry and transmit WNV. The mosquito species that most transmits WNV to humans in Halton is called Culex pipiens, also known as the rain-barrel or house mosquito. Culex pipiens does not usually live in swamps, bogs or marshes but lives in close association with humans. It prefers to breed in all types of neglected, water-holding objects found within cities and suburbs, and it overwinters in basements and sewers. This means that the mosquitoes in town or city backyards are much more likely to be carrying West Nile virus than the mosquitoes that might be encountered on a camping trip up north. Halton residents need to protect themselves from mosquito bites around their homes.

The following are steps that residents can take to protect themselves and their families from mosquitoes:

-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.

A map showing the locations of standing water sites that have had larvicide applied is available on the Health Department’s website at www.halton.ca/wnv.

To report standing water or for more information about West Nile virus, please dial 311 or call Halton Region at 905-825-6000, toll free 1-866-442-5866, or e-mail wnv@halton.ca.

The Regional Municipality of Halton serves more than 500,000 residents in the City of Burlington, the Town of Halton Hills, the Town of Milton, and the Town of Oakville. Halton Region is committed to meeting the needs of its residents through the delivery of cost-effective, quality programs and services, including water and wastewater; Regional roads and planning; paramedic services; waste management; public health; social assistance; children’s and seniors’ services; housing services; heritage programs; emergency management and economic development. For more information, dial 311 or visit Halton Region’s website at www.halton.ca.