West Nile Virus

Reporting a dead bird and additonal information from BC Centre for Disease Control

Nice weather in British Columbia also means the start of mosquito season. Mosquitos are more than a nuisance; a small percentage cause infections that can lead to serious illnesses, such as West Nile Virus. Refer to Island Health's (VIHA) Emergency Management webpage for health-related response plans.

What is West Nile virus?

West Nile virus is a mosquito-borne virus. The virus is normally transferred between birds and mosquitos. Some species of mosquitos can spread the disease to humans. While the risk of becoming seriously ill from West Nile virus is low, serious illness can result, so it is important to take precautions.

Where has West Nile been detected?

The virus was first detected in the West Nile region of Uganda in Africa in 1937. The virus was first detected in North America in New York State in the summer of 1999. By the end of 2002 the virus had spread to 5 Canadian provinces and 43 US states, including Washington State.

What actions are the province and the North Cowichan taking?

North Cowichan and provincial authorities are working together to deal with West Nile Virus. Those activities include:

  • Monitoring for the presence of West Nile virus and the sharing of monitoring data (ie. mosquito larval sampling, adult mosquito trapping, and dead bird collecting).
  • Informing the public about West Nile virus and how to minimize the risk of becoming infected.
  • Coordinating the development of mosquito control plans.

North Cowichan currently sits on the Vancouver Island Health Authority's Southern District West Nile Virus Workgroup in Victoria. This workgroup provides an opportunity to share information on what West Nile Virus related activities other local governments, the provincial government, and the BC Centre for Disease Control are engaged in, with the primary purpose being to coordinate the activities of all levels of government.

The District has an ongoing District-wide mosquito monitoring program. Potential WNV mosquito breeding hot spots have been located, mapped, and prioritized for treatment as part of the District's WNV response plan. If WNV is detected in the area, the District will implement its WNV Response Plan in consultation with the local medical health officer.

What can you do to minimize the risk of becoming infected?

There are many simple things that the public can do to help reduce the risk of becoming infected.

  1. Reduce areas with standing water on your property to reduce the area where mosquitos can breed.
  2. Where areas of standing water on your property cannot be reduced, Health Canada has approved a larvacide product called Aqua Bac which can be applied to bodies of standing water to kill mosquito larvae. Be aware the use of Aqua Bac is only permitted on the condition that the water body: 1) is man-made; 2) lies entirely within your property limits; and 3) does not flow off of your property.
    1. If these conditions are not met then a permit from the Ministry of Water, Land, and Air Protection is required. Contact your local garden centre for information on cost and availability of Aqua Bac.
  3. When outdoors, protect yourself by wearing shoes, socks, long pants and long-sleeved shirts. Wear light coloured clothing; dark coloured clothing tends to attract mosquitos.
  4. Use mosquito repellents that contain DEET (the percentage of DEET in repellents should not exceed 30% for adults and 10% for children). When using insect repellents be sure to follow the directions (for more information on insect repellents visit Health Canada's web page).
  5. Install screens on your doors and windows.
  6. Mow your lawn regularly to decrease the area where mosquitos can rest during the hot part of the day.
  7. As much as possible, avoid forested areas during the day.

What are the symptoms of an infection from West Nile virus?

Most mosquito bites cause itching and minor irritation. A small percentage can lead to illnesses such as West Nile virus. Some symptoms of West Nile virus are:

  • High fever
  • Muscle weakness or paralysis
  • Stiff neck
  • Confusion
  • Severe headache
  • Sudden sensitivity to light
  • Extreme swelling or infection at the site of the mosquito bite


If you are concerned about your symptoms, seek medical advice through your family doctor or call the BC Nurse line at 1-866-215-4700.