Confirmed case of West Nile virus in Alberta

  • Aug. 22, 2012 4:30 p.m.

Provincial health officials have announced Alberta’s first confirmed case of West Nile virus since 2010.

“This individual has not traveled outside of Alberta this season, meaning she was bitten by an infected mosquito right here in our province,” said Dr. David Strong, Alberta Health Services’ acting south zone medical officer of health. “This is an unfortunate reminder that some mosquitoes do carry West Nile virus, so it’s simply best to avoid being bitten at all.”

Due to patient confidentiality legislation, AHS will not be releasing further information about this West Nile virus case except that the woman is under 65 and lives in southern Alberta.

West Nile virus is a mosquito-borne virus that can cause West Nile Non-Neurological Syndrome (formerly known as West Nile fever). Occasionally it can cause the more serious West Nile Neurological Syndrome. West Nile virus was first isolated in 1937 in the West Nile district of Uganda.

Since then, there have been outbreaks in Egypt, Israel, South Africa, and in parts of Europe, Asia and North America.

Whether gardening, golfing, fishing or even just relaxing outdoors, there are several tips Albertans should follow, including applying mosquito repellent with DEET, wearing long-sleeved, light-colored shirts and pants and wearing hats as well.

Folks should also consider staying indoors at dawn and dusk when mosquitoes are most active, he said. “These steps can make it harder for mosquitoes to find you – and, remember: if they can’t find you, they can’t bite you.”

Officials say there are 44 species of mosquitoes in Alberta and that of these, the Culex tarsalis has been identified as the species most likely to carry and transmit the virus from infected birds to people and horses.

The breeding season of the Culex tarsalis runs from mid-June to September. The risk of contracting West Nile virus increases during this period and peaks during August.

Some people who become infected with non-neurological syndrome show no symptoms at all. However, symptoms that could occur can include fever, chills, nausea, vomiting, fatigue, skin rash, swollen glands and headache.

For the small number of individuals who do develop the neurological syndrome, infection can lead to tremors, drowsiness, confusion, swallowing problems, high fever, unconsciousness, paralysis and even death.

As of Aug. 11, 34 human cases of West Nile virus infection have been reported in Canada (not including Alberta’s first case). Last year, 102 cases of West Nile virus were confirmed in Canada.

Looking back, 2007 saw quite a high incidence rate across the prairies which did include some travel-related cases – 320 in Alberta, 1,456 in Saskatchewan and 587 in Manitoba.

For more information, visit or call Health Link Alberta toll-free at 1-866-408-5465 (LINK).