West Nile Virus Confirmed In Alberta Mosquitoes

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West Nile Virus

Mosquitoes with West Nile virus found in several surveillance stations in the southern half of Alberta, are a reminder to Albertans about the importance of taking precautions against the disease.

Mosquito pools positive for West Nile virus were collected in Provost, Taber, Raymond, Calgary, Brooks and Burdet. These mosquitoes are Alberta's first confirmed evidence of the West Nile virus this year.

"Although we have no reported human cases of West Nile virus infection yet, Albertans, especially in the south, should now be taking precautions," said Dr. Shainoor Virani, Acting Deputy Chief Medical Officer of Health. "The most effective means of reducing the risk of infection is to take simple personal precautions to avoid being bitten by mosquitoes, such as using a mosquito repellent containing DEET."


Other ways to protect oneself include avoiding outdoor activities as much as possible at dusk and dawn, when mosquitoes are most active, and wearing long sleeves, long pants and socks and/or netted protective clothing.

Warm weather conditions have been ideal for the development of Culex tarsalis mosquitoes, which commonly carry the virus. Culex tarsalis numbers are increasing from the eastern border of the province across to the foothills, and positive pools are likely to be found in more northern areas including Edmonton. These mosquitoes are expected to reach the peak of their reproductive and biting activity during the first two weeks of August.

Now in its fifth year, Alberta's mosquito surveillance program is run by participating municipal authorities and overseen by Alberta Environment. Since June 19 when this year's monitoring began, over 40,000 mosquitoes have been captured, sorted and tested.

The virus was first detected in Alberta in 2003. Of the 1,417 mosquito pools sampled province-wide that year, 31 tested positive.