Jason Unrau
Northern News Services
Wednesday, June 20, 2007

YELLOWKNIFE - Mosquito season is upon us but the annual nuisance should be just that as the chance of West Nile virus penetrating our climate zone is slim, according to Andre Corriveau, chief medical officer for the NWT.

"We've never had it up in the North and don't expect to see it in our part of the country," said Corriveau.

He cited our shorter summers as the reason the virus is unlikely to make an appearance.

"It takes time for an outbreak to occur," he said. "First you need a few birds that bring it back here then six to eight weeks for a (virus) cycle to emerge and by then we're in August and then it's frost."

Transmitted through mosquitoes from birds to other mammals, West Nile has been detected in Sask. mosquito populations this year. Last year, Quebec reported one case of human infection, there were 42 in Ontario, 50 in Manitoba, 19 in Saskatchewan and 39 in Alberta. All other provinces and territories remained free of human incidences of West Nile.

"Our concern is primarily southern Alberta," said Jeannie Smith of Health Canada in Edmonton. "The mosquito may travel or wander but that's where that (culex tarsalis) group is."

Culex tarsalis is the sub-species of mosquito known to carry the virus in North America and though found in the NWT, the absence of West Nile in the territories' bird population, competition among other mosquito sub-species and shorter summers add up to a natural defence mechanism.

However, Corriveau said that territorial medical staff are aware of the virus's symptoms, which are flu-like, in case a person returning to or visiting the North brings West Nile with them. The danger to people is not the virus itself but the swelling of the brain - causes that can lead to complications and in death.

Those most at risk are people with weakened immune systems such as young children and the elderly.

"We still want people to know about it," said Corriveau. "Northerners travel south all the time so they might end up in a part of the country that has it so they need to know about it and, of course we want our physicians to know."