Putting the bite on West Nile virusSummer is on the way and the warnings about West Nile Virus are rife. Government publicity campaigns warn us to cover up, use insect repellent, and stay away from still water, which may attract mosquitoes carrying this potentially deadly virus. |
|
![]() [ 2003-06-11 ] |

Dr. Neil Rau, centre, flanked by Ontario Health Minister Tony Clement and medical officer of health Dr. Colin D'Cunha, was the first to discover the West Nile virus in humans in Canada. "When you identify something like this for the first time, it seems incredulous to you," he says.
But when Dr. Neil Rau diagnosed the first human cases of West Nile virus in Canada last August, few took the threat seriously. Even Rau, an infectious disease specialist at Mississauga's Credit Valley hospital, could hardly believe what he found.
"I identified the first cases of it in Canada in the Peel and Halton regions. My first reaction was 'Gee, this theoretically looks like West Nile Virus...' But when you identify something like this for the first time, it seems incredulous to you."
There had been some warning, however. Bob Nosal, medical officer of health for the Halton region, had been monitoring reports of the virus in dead crows, and noticed the number of infected birds was increasing. Nosal feared local residents would be next.
Rau brought his findings to the health authorities. By Aug. 31, 2002, Ontario's medical officer of health, Dr. Colin D'Cunha, announced the province's first probable West Nile cases. Then a number of other, previously undiagnosed cases were identified.
By the end of 2002, there were 308 confirmed cases in Ontario. Eighteen of the people infected in the province died -- but only eight deaths have been directly attributed to the virus.
"One thing to keep in mind is that four out of five people who are infected get no symptoms," Rau says. "And of those who get symptoms only one out of 20 get serious symptoms. Still, you don't want to be one of the few who is seriously infected."
Initial symptoms of the disease include headaches and fever, body aches, rashes and swollen lymph glands. Most people recover. But the few unlucky people may develop encephalitis -- a dangerous swelling of the brain.
Rau says there's no cure yet for this virus, and while developing a vaccine may be possible, it would be very expensive -- and probably not financially viable -- to vaccinate the public.
Now Rau urges other health workers to be more active in their approach to diagnosing West Nile virus. Instead of discovering a case and identifying it as West Nile, he urges doctors to test anyone who suffers from the virus's flu-like symptoms. He also encourages the public to be both vigilant and calm as more research is conducted on the virus.
First identified in 1937 in the West Nile region of Uganda, this virus was most commonly found in Africa, the Middle East and Eastern Europe.
West Nile virus was unknown in North America until 1999, when an outbreak in New York killed seven people, including one Canadian. The virus then spread.
West Nile was first detected in Canada in the summer of 2001 when tests on 128 dead birds showed they had been infected with the virus.
Dr. Neil Rau was the first to identify cases of West Nile virus in CanadaÕs human population in 2002 by diagnosing a case in the Peel and Halton region.
Mosquitoes contract West Nile Virus when they bite infected birds. The virus can be spread to humans thorough bites from infected mosquitoes.
(Susan Poizner (susan.poizner@sympatico.ca) is a Toronto-based freelance writer.)