The first incidence of this disease in North America was in 1999 in New York state; since then the disease has killed 84 people in 36 States. People can become infected when bitten by an infected mosquito. Mosquitoes can be infected when they feed on the blood of birds that carry the virus.
This year West Nile virus has already been confirmed in a dead crow in Ontario. In 2002 there were 281 confirmed cases among birds in Ontario, in addition to 88 cases in Winnipeg, 139 cases in Quebec, 4 cases in Nova Scotia and 44 in Saskatchewan. Researchers looked for declines in bird numbers in that year's Christmas Bird Count, which might have indicated the spread and prevalence of the virus in Canada.
Last year was also the first year in which the West Nile Virus infected people in Canada: 17 people died in Ontario, Quebec had two fatalities in autumn.
The virus can be serious to people, especially the elderly, very young and those with weakened immune systems. But the chances of getting this disease are very low - even if bitten by a mosquito infected with the virus - less than 1% of people who are infected become sick enough to seek medical attention, and the chances of dying are currently 1 in 10 billion in Canada.
A woman from Ontario may be the first fatal case of the West Nile virus being transmitted through a blood transfusion. Health officials in the US have confirmed that West Nile is also transmissible through organ donation, after four people in Florida contracted the virus after receiving organs from a person who had the disease. Canadian Blood Services has created a West Nile Virus Task Force and is looking into having screening procedures in place by July 1st, 2003.
West Nile Prevention Measures in 2003
Ontario was the first province to have human cases of this disease. The province has pledged $7 million to combat West Nile, and has set up a Health Connection line 1-800-361-5653 where people can call to report dead birds. They have also authorized the use of the pesticide Malathion if other methods of mosquito control are non-effective. Malathion is highly toxic and can adversely affect the nervous system and worsen asthma rates. In an effort to reduce the time-lag in the confirmation of samples, Ontario's Chief Medical Officer of Health has announced that Ontario will no longer be using the Federal Laboratory in Winnipeg, and will instead process all samples in the Provincial Health Lab.
The city of Toronto has allocated $1.6 million CAD for public education and to apply the larvicide methoprene in its 175,000 storm sewers. The city has also stated it's intention of using malathion as a last resort. Recent recommendations from the city of Ottawa's medical officer call for $600 000 CAD to be spent on West Nile prevention measures such as public education, larvicide application and bird monitoring. Conservation official's from London's Upper Thames River Conservation Authority have suggested using native bat species as a natural method of adult mosquito control. An adult bat can consume approximately 3000 mosquitoes in an evening. Bats can be encouraged to live in an area by putting up bat boxes (where they can roost) in parks or backyards.
Environmentalists are concerned with the spraying of methoprene, while one of the least toxic of pesticides it will bind with chlorine (which could occur if the water from the storm sewer to enter a water treatment plant) to form a presistent environmental toxin, and it also kills non-target beneficial insects. Instead the bacterium Bt, currently in use in West Nile control programs in Quebec, a natural disease affecting only black flies and mosquitoes could be used a biological means of mosquito control.
Quebec confirmed the first case of West Nile in that province last September. This year they are increasing the number of monitoring stations to 25, and have started applying the biological larvicide Bt to six communities in the Montreal area.
Alberta had two cases, both of whom contracted the disease while on vacation in the USA. However, health officials are expecting it to show up this year. The government has pledged $2.5 million for education, including a website, dead bird monitoring and horse vaccinations. The City of Calgary will spend $700,000 on West Nile control, it currently sprays for a different species outside of the city limits.
British Columbia was also free of the disease in 2002, however with last year's rapid spread of the disease across North America and into Washington State, health officials in BC are implementing procedures and earmarking $500,000 to deal with the virus in 2003. BC's mosquito and bird testing program is scheduled to begin in May, 2003. Starting this year dead birds will be tested at the BC Animal Health Centre in Abbotsford instead of sending specimens out of province.
Manitoba saw West Nile affect horses and wild bird populations in 2002. The province has pledged $5.8 million dollars for surveillance, public education and mosquito control. The City of Winnipeg's Insect Control Department has been given a budget of $3.5 million to use biological larvicides (to reduce the use of chemicals) and will be increasing their larvicide application activities to reduce the need for mosquito fogging later in the season.
Nova Scotia had four birds test positive for the disease in 2002. The province will continue its bird monitoring program, expand on a public information program and is considering setting up a toll free number for public inquiries.
New Brunswick has announced that it will continue it's surveillance and education campaigns including a bilingual toll free information line 1-800-580-0038, and non-pesticide methods of mosquito populations.
Prince Edward Island was spared the virus in 2002, however, in anticipation of its arrival this year they have set up a website dedicated to West Nile Virus information, and have set up a number 1-902-368-4683 where people can report dead birds. PEI's Atlantic Veterinary College will provide testing for all animal specimens from Atlantic Canada. The province is also asking its residents to eliminate standing water on their properties.
The North West Territories and the other Northern territories of Yukon and Nunavut have held consultations on the threat of West Nile. Due to the climate and nonprevalence of the species of mosquito which acts as a vector (or transmitter) for West Nile, these territories are deemed not at a high risk. However, health officials are setting up a surveillance program for dead birds, and an education campaign for people who might be travelling to parts of Canada where the disease is more prevalent.
The West Nile Virus And Animals
Animals can also be infected with the West Nile virus and the Humane Society of Canada is urging people to take the appropriate precautions to protect themselves and their animal companions.
"Horses are particularly susceptible - even more so than humans - approximately one out every three horses die after being infected by the West Nile virus," says Michael O’Sullivan, HSC Executive Director. "Fever, lack of coordination, weakness and partial paralysis are a few signs that may indicate that a horse has been infected with the virus. In 2002, Manitoba had 236 confirmed cases, Saskatchewan had 10 cases, In Ontario, West Nile was confirmed in 101 horses. In Quebec, the virus was been found and confirmed in 3 horses. There is a West Nile vaccine for horses that is available in Canada from licensed veterinarians. Stables outside of Saskatoon are starting to implement a vaccination program to ensure that horses will have some resistence before mosquito season begins," states O’Sullivan.
The Metro Toronto Zoo received $50,000 from the city for West Nile control measures such as larvicide application and vaccinations for all birds, primates and horse-like animals. Last year tests revealed that Amos, a 25-year-old Barbary Ape that died last August at the Metro Toronto Zoo, which also lost 9 exotic birds, had the virus. In Manitoba, the West Nile Virus was found in a flock of Canada Geese. While the virus showed up in the goslings, adults appeared to be resistant. The disease also shewed up in duck and crow populations, as well as an individual owl. Further testing on a suspected Richardson Ground Squirrel with West Nile have shown that it did not have the virus. In the US, 8 Humboldt penguins died from West Nile Virus at the Milwaukee County Zoo.
"Dogs and cats may also be at risk to this virus. If you are concerned that your pet may have contracted this virus or if you would like more information about how you can help to protect your ‘best friends’ from the West Nile virus, contact your veterinarian," advises O’Sullivan.
Ways That You Can Reduce Exposure to Mosquitoes and The West Nile Virus.
- Empty or remove containers, such as buckets and old tires, where water accumulates, as these are prime breeding areas for mosquitoes.
- Change water in birdbaths several times a week.
- Clean up grass clippings
- Clean rain gutters.
- Screen rain barrels.
- Keep window, door and porch screens in good repair.
- Ensure that baby carriages are closed and in good repair.
- Try to avoid areas where mosquitoes are numerous, such as swampy, wooded areas.
- Try to minimize outdoor activities from dusk to dawn, as this is when mosquitoes are most active.
- When outdoors and mosquitoes are present, wear light-coloured clothing. Long pants, a long-sleeved shirt, socks, shoes and a hat are also recommended.
- Use a safe, insect repellent and follow the manufacturer’s directions for its use.
- Protect pets in similar ways. Try to keep horses stabled at night and in the early morning when mosquitoes are most active. There are bug sprays for horses. Try to minimize other pets’ exposure to mosquitoes. There are insect repellents made for dogs and cats.
The West Nile virus is a disease that shouldn’t be taken lightly. However, by taking some preventative measures to protect our two-legged and four-legged family members, we can further reduce the already very small chance of being affected by this virus.
CONTACT: Al Hickey or Michael O'Sullivan by calling toll free 1-800-641-KIND or Michael on his cell phone (416) 876-9685 or at www.humanesociety.com
[For more than 17 years, Al Hickey was the Chief Executive of the BC SPCA and before that headed up the Alberta and BC Chambers of Commerce, and the Executive Director of the Boys and Girls Club of Greater Vancouver. He has 6 grandchildren.
A father with two small children, and a houseful of dogs and cats, O'Sullivan has worked in Canada and in over 85 countries during the last 30 years helping people, animals and nature.]
The Humane Society works to protect dogs, cats, horses, birds, livestock, lab animals and the environment. They carry out hands on programs to help animals and nature, mount rescue operations, expose cruelty through hard hitting undercover investigations, work to pass laws to protect animals, fund scientific research, support animal shelters and wildlife rehabilitation centres and spread the word about how to help animals and nature through humane education.