How is West Nile Virus spread?

West Nile Virus is spread from infected mosquitoes to humans. Mosquitoes get the virus by feeding on the blood of infected birds. WNV is NOT transmitted from person-to-person. You cannot get WNV by touching or kissing someone who is infected, or being around a health care worker who has treated an infected person. WNV cannot be passed from infected animals (horses, birds, or pets) to people.

How can I protect myself from West Nile Virus?

If there are reports of infected mosquitos, infected horses or dead birds in your area, you should take immediate action to minimize your risk of mosquito bites.

• Limit the time you spend outdoors at dawn and dusk, when mosquitoes are most active
• Wear light-coloured long-sleeved shirts, long pants and a hat when outdoors
• Use an insect repellent containing DEET and follow the manufacturers' directions for safe use
• Make sure that door and window screens have no holes and fit tightly

Can I still have a birdbath full of water, as long as the water is changed every other day?

Mosquitoes need standing pools of water to breed, and the larvae needs two to three days to hatch. If you replace the water in your birdbath every two days during the mosquito breeding season, they will have no opportunity to reproduce.

Assuming that household pets are at risk of contracting West Nile Virus as well, how can we protect them?

Any mammal or bird can be exposed to West Nile Virus if bitten by an infected mosquito. Birds and horses are particularly susceptible. Cats and dogs can become infected, but they do not appear to develop signs of this disease except in rare circumstances. To protect your household pets, consider keeping them indoors when mosquitoes are most active at dawn and dusk. Pet bowls should not be left outside where the water might become stagnant. Do NOT spray your pets with products containing DEET; there are safe insect repellants available for pets, simply ask your veterinarian and follow the label directions.

You recommend the use of federally regulated insect repellents that contain DEET, and that the concentration of DEET should be no greater than 30% for adults and no greater than 10% for children. Can you recommend any products that meet these specifications?

We cannot recommend specific products. Repellents containing10% or less DEET are good for most uses. Higher concentrations of DEET last longer but are not more effective. Remember that product labels may use the chemical name for DEET, so look for N,N-diethyl-m tolumide or N,N-diethyl-meta toluamide and N,N-diethyl-3-methylbenzamide. For more detailed information see Health Canada's brochure, Safety Tips on Using Personal Insect Repellents, or call 1.800.267.6315.