Canada has worst year ever for West Nile virus
Pastor Dale Morgan
Canada has worst year ever for West Nile virus*
Updated Sat. Sep. 15 2007 9:32 AM ET
The Canadian Press
WINNIPEG -- New numbers show Canada is experiencing its worst year ever
for West Nile virus, and as strange as it sounds, one reason could be
the lack of a certain type of mosquito.
So far this summer, 1,790 people have become infected with West Nile,
compared with the record of 1,481 cases in 2003. This year, the vast
majority of the cases are in the Prairies, where the deaths of seven
people are linked to the virus. Saskatchewan Health officials said
Friday a total of 1,054 confirmed or suspected cases have been reported,
and Manitoba has seen more than 500 cases.
The exact reasons why West Nile has hit hardest in the Prairies have
left experts scratching their heads.
"It is a little odd, and we're not sure exactly why that is," said
Robbin Lindsay, a Winnipeg-based entomologist with the Public Health
Agency of Canada.
One obvious factor is the weather, he said. A wet spring and hot summer
were perfect for the development of Culex tarsalis mosquitoes, the type
that transmits West Nile to humans.
But those same conditions weren't right for the breeding of nuisance
mosquitoes, the biting bugs that although annoying, don't carry West Nile.
When they aren't bothered by mosquitoes, people sometimes become
complacent and forget to take precautions against West Nile, like
wearing bug spray, Lindsay said.
"If you ask people on the street if it was a bad year for mosquitoes,
they'll say, 'God, no, it was beautiful, you really didn't get a lot of
bites,' " he said.
"That translated into not very many people thinking there was a big risk."
Dr. Joel Kettner, Manitoba's Chief Medical Officer of Health, said a
heightened awareness of the virus both with doctors and patients could
be another reason why the province is seeing so many cases this year.
"We definitely have more testing for West Nile virus than ever before,"
Kettner said.
With more than 1,000 cases, Saskatchewan has the highest number of human
cases of West Nile in Canada this year. Of those who are sick, 30 have
West Nile Neurological Syndrome - the most severe symptoms.
Medical health officer Dr. Shauna Hudson said it's hard to know how much
higher the numbers will climb.
"It depends on how many physicians repeat testing, it depends on what
our public health inspectors and public health nurses find on their case
investigations.
"But I think we'll see it increase."
Most people infected with the virus don't show any symptoms, but the
severe form of West Nile can cause swelling of the brain and spinal
cord, as well as paralysis, or even death.