Daily BrewHealth Canada officials warn of West Nile virus comeback
Health officials are warning against complacency as Canada experiences an apparent flareup of the West Nile virus.
Several cases of the mosquito-borne virus, which can be fatal in rare instances, have been detected this summer in Regina, Quebec and Ontario, the Globe and Mail reports.
In Ontario, 89 mosquito pools — standing water where the bugs lay their eggs — have tested positive for West Nile, the most since 2002.
CBC News reports two Windsor, Ont., residents have contracted West Nile, with one 68-year-old man admitted to hospital last week and now listed as unresponsive in serious condition.
The U.S. Centers for Disease Control and Prevention has reported 241 West Nile cases so far this summer, the Globe says, including four deaths.
"It is not clear why we are seeing more activity than in recent years," Marc Fischer, a medical epidemiologist with CDC's arboviral diseases branch, told the Globe.
Dr. Colin Lee of Public Health Ontario recently told CTV's Canada AM that Canadians should not let their guard down about West Nile.
"This is probably here to stay every summer and we are advising the same kinds of precautions," said Lee.
Toronto health officials last week reported two probable human cases of the virus, including an 80-year-old man who had to be hospitalized. Both cases were thought to have been contracted in the city, CTV News said.
Another case turned up in Regina last Friday when the virus was found in a would-be blood donor.
Lee said more mosquitos appear to be carrying the virus this year, which means Canadians must protect themselves and ensure there's no standing water where they can breed.
According to Health Canada, that means minimizing time spent outdoors between dusk and dawn when mosquitos are most active, wearing long-sleeved shirts, long pants and a hat, preferably light-coloured, using insect repellants and making sure door and window screens fit tightly.
You should also check your yard for stagnant water in places such as swimming-pool covers, saucers under flower pots, pet bowls and wading pools.
The Globe notes West Nile first surfaced in Canada in 2001 in Toronto and spread steadily west. Health officials began monitoring the disease the following year.
The worst year so far has been 2007, with more than 2,200 cases, including 12 deaths, according to the Public Health Agency of Canada.
Officials won't know how this year compares until later in the fall, since the prime season for transmission is the August-September period. But entomologist Phil Curry, West Nile co-ordinator for Saskatchewan, told the Globe weather conditions for mosquitos have been optimal in Ontario, Saskatchewan and Manitoba.
"This will be a build-up year," Mr. Curry said, adding that the earlier prevalence of West Nile virus in mosquito pools is a warning sign.
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"I don't think it will reach the worrying levels as we had a couple of years ago, but the virus tends to be cyclical … and this is it coming back."
Health Canada notes most people infected with the virus show no symptoms and do not get sick. Others experience a flu-like illness that can appear anywhere from two to 15 days, sometimes including a mild rash and swollen lymph glands.
Older people and those with weakened immune systems are at greater risk for serious problems, including inflammation of the brain and spinal cord, displaying symptoms such as severe headache, high fever, stiff neck, vomiting, confusion and paralysis.
The disease can also leave long-term health effects, such as muscle weakness, paralysis, fatigue and headache, as well as cognitive problems.
