West Nile Virus in Niagara

Detection and treatment of the virus

The virus can be confirmed in humans by testing the blood or fluid that surrounds the brain and spinal cord.

There is no specific treatment, medication or vaccine for West Nile virus. In the most severe cases, hospitalization is required for management of symptoms and intensive, supportive care.

Get statistics about West Nile virus in Niagara and Ontario.

Reduce the risk of West Nile virus

The best ways to reduce the risk of infection are:

• Reduce standing water where mosquitoes like to breed
• Avoid infested areas
• Wear long sleeved shirts, long pants, hats, socks and shoes.
• Repair damaged doors and window screens.
• Use an insect repellent that contains DEET or Icaridin. Always follow the manufacturer's instructions

How to reduce mosquito breeding areas around your home

Mosquito larvae can develop in water that has been standing for more than four days.

• Keep your yard clean

  Our values guide the committee's decision making and actions:

  • Remove discarded tire and clean up junk piles that collect water
  • Cover containers or use lids to prevent water from collecting in the bottom of garbage cans
  • Use screen or fine mesh to cover rain barrel
  • Clean pet food and water bowls and store indoors when not in use
• Clean out eaves, gutters and drains
  • Clear leaves, twigs and debris from eavestroughs, storm and roof gutters throughout the summer
  • Make sure drainage ditch is not clogged
  • Check flat roofs frequently for standing water
• Maintain yards and lawns
  • Fill in low depressions in lawn areas
  • Eliminate standing water in gutters or storm drains to prevent small ponds
  • Install screens over catch basins
  • Grass clippings, leaves or other decaying debris, such as apples or berries that fall from trees should be mulched to prevent organic matter from going into catch basins or storm sewers as food source for mosquito larvae
  • Turn over compost frequently
• Always inspect swimming or wading pools and ponds
  • Remove water that collects on pool covers
  • Make sure the pool's pump is circulating water
  • Turn over wading pools when not in use
  • Use a pump to circulate water in your pond
• Eliminate stagnant water where mosquitoes lay their eggs
  • Clean up and empty water in toys, birdbaths, tires, flowerpots, wheelbarrows and other garden objects
  • Drill holes in the bottoms of containers so water can't collect
  • Change water in bird bath frequently
• Repair window screens and screen doors
  • Check window and door screens and repair any holes
  • Ensure screens fit tightly into to window or door frames to prevent mosquitoes from getting inside
  • If you don't have screens, try and keep windows closed between dusk and dawn
  • Install screens on crawl spaces and attic vents
• Fix faucets and hoses
  • Repair any leaks to faucets and hoses to prevent possible breeding sites
  • Prevent water from pooling around downspouts and air conditioners

Larvicide for mosquito control in Niagara

Municipal catch basins in each city / town in Niagara are treated during the summer to help control the breeding of mosquitoes. Larvicide is placed in areas of standing water where mosquitoes breed, such as ditches, shallow ponds and sewer drains.

The larvicide used has been approved for mosquito control by Health Canada and poses no risk to human health. It is in the form of pellets or granules which dissolve in water.

Storm drains are marked with a coloured dot to show it has been treated with larvicide. If there is more than one colour marking, the storm drain has been treated more than once.

For more information about larvicides, visit GDG Environment.

Notice of application

From June 1 to Oct. 31, 2025, Niagara Region will be conducting a larviciding program in the communities of St. Catharines, Niagara Falls, Welland, Thorold, Port Colborne, Pelham, Fort Erie, Niagara-on-the-Lake, Lincoln, Grimsby, Wainfleet and West Lincoln.

Under the authority of the Medical Officer of Health, this program is to control larval mosquitoes to prevent their development into carriers of West Nile virus.

The larvicide Altosid Pellets (PCP No. 21809) and VectoLex WSP (PCP No. 28009) will be applied into municipal catch basins. The larvicide VectoBac 200G (PCP No. 18158), VectoBac 1200L (PCP No. 21062), My-Crobe XT (PCP No. 34633) and VectoLex CG (PCP No. 28008) may be placed into selected bodies of surface water such as ditches and ponds, depending on the results of testing for the presence of mosquito larvae.

All larvicides will be applied by Ministry of the Environment, Conservation and Parks licensed applicators or technicians.

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