First Nations gearing up to fight West Nile viru

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The arrival of mosquitoes has never been anybody's favorite sign that the long winter is finally over, but since the arrival of the West Nile virus in Canada, these tiny creatures are being seen not just as an annoyance, but as a real threat to people's health.

To help deal with that threat, Health Canada will be working closely with First Nations bands, chiefs and councils this year to help prevent the spread of the virus within their communities.

This partnering with First Nations to co-ordinate surveillance, testing, education, and methods of preventing spread of the virus, as well as ways to respond if the virus is detected, is just one of the ways the federal department is working to try to control the spread of the virus during the coming mosquito season.

The West Nile virus has been around for decades, and was first identified and isolated in the West Nile region of Uganda in 1937. The virus first shows up in birds, and can be spread to humans if they are bitten by a mosquito that has been infected by feeding on a bird that carries the virus.

Over the years, there had been outbreaks of the virus in Egypt, Israel, South Africa, and in parts of Europe. The first signs that the virus has arrived in North America came in August 1999, when it turned up in dead crows found on the grounds of the Bronx Zoo in New York City. By the end of 2000, the virus has spread as far as the Canada/U.S. border. The first case of West Nile virus in Canada was confirmed on Aug. 22, 2001 in a dead bird found in Windsor-Essex County in southern Ontario, and began to spread from there.

According to Dr. Harvey Artsob, chief of zoonotics diseases and special pathogens for the population and public health branch of Health Canada, the cases of West Nile virus reported in Canada and the United States in 2002 made it the largest mosquito transmitted epidemic ever documented in North America, and the largest West Nile epidemic ever documented anywhere in the world. To date, there have been 325 human cases of West Nile virus confirmed in Canada. In three of those cases-including two in Alberta-it is believed the people contracted the virus while travelling.

All told, a total of 18 deaths have been linked to the virus, including four deaths where the virus itself was listed as the primary probable cause of death.

While the number of positive cases of human contraction of the virus has been limited to Quebec and Ontario, dead birds have tested positive for the West Nile virus as far east as Nova Scotia and as far west as Saskatchewan. In Ontario, at least two of the birds testing positive were found on First Nations. And while no one can predict where the virus will show up this year, it is likely to continue to spread, possibly reaching into Alberta and British Columbia this summer.

Many people who contract the West Nile virus have no symptom, while others become mildly ill. In mild cases, the symptoms can include fever, headache, body aches, a mild rash, or swollen lymph glands. In others, especially those with weakened immune systems, the virus can cause more serious health effects, including meningitis-inflammation of the lining of the brain or spinal cord- or encephalitis, and can be fatal. In these severe cases, symptoms could include rapid onset of a severe headache, high fever, a stiff neck, nausea or vomiting, drowsiness, difficulty swallowing, confusion, loss of consciousness, lack of coordination, muscle weakness and paralysis. Last year a number of additional symptoms were added to the list, including movement disorders, muscle degeneration, and symptoms similar to that experienced in Parkinson's disease and poliomyelitis.

While in the past, statistics have shown that about 80 per cent of people contracting the virus won't have any symptoms, about 20 per cent develop mild symptoms and less than one per cent develop more serious symptoms, new research has shown those numbers may need modifying, Artsob explained.

"At a recnt meeting in the United States they have said that they have done some follow-up studies on the number of individuals who are seriously ill, and they're starting to question, not so much that 80 per cent or so will be asymptomatic, without any symptom of disease, but whereas we used to categorize approximately 20 per cent of people would have just flu-like illness, and less than one per cent with serious neurological disease, we're starting to think it might be more than less than one per cent, and some of that 20 per cent might include people with a wider range of symptoms than we had previously recognized," he said.

A West Nile virus fact sheet on the Health Canada Web site lists the groups who have a higher risk of developing serious health effects after contracting the virus. These groups include people over 40, people with chronic diseases such as cancer, diabetes, alcoholism, or heart disease, and people that require medical treatment such as chemotherapy that may leave them with weakened immune systems.

That list concerns Ruby Jacobs, director of health services for Six Nations of the Grand River council. Six Nations is located in southern Ontario, the region of Canada where the first West Nile outbreaks occurred, and is the country's most populous First Nations community. According to a recent study looking at the health of Six Nations members, there are high percentages of the population with diabetes, cancer and cardiovascular disease.

"There are high numbers in all of those areas. Our study actually said around 49 per cent either have or will have diabetes. And the whole statistics were just horrendous . . . many people are involved in those kinds of diagnosis. And you know, the state of health is one major factor in whether you catch disease or not," she said.

The West Nile virus has been a concern for Six Nations for a while, Jacobs said. The community took part in bird surveillance last year, with about seven birds picked up for testing. The brd surveillance will continue again this year. In fact, one dead crow has already been picked up and sent off to be tested for the virus. This year, work will also be done to monitor the mosquito population, to try to identify areas where the insects reproduce.

Six Nations will also be focusing on educating its members, and increasing their awareness of ways they can work to reduce the spread of the West Nile virus, Jacobs explained.

"We've got these things you can do in your environment to reduce the reproduction of mosquitoes. Like emptying out stagnant water in any kind of a receptacle around your property, and making sure your house has got proper screens on and so on, to prevent entry into the houses. And then for yourself, there's personal things you can do . . . like wearing proper clothing at peak times like dusk and dawn, where you'd wear long pants and socks and shirts and that so that they couldn't bite you," she said.

"We're working with Health Canada, the environmental health office, very closely on this. All the components that will be concerned in our community, like probably health, health services staff and the environmental staff, are all working together in a collaborative effort to reduce the reproduction," she said.

As for chemical means of controlling mosquito populations, such as larviciding, which targets mosquito breeding sites, and adulticiding, which involves spraying or fogging insecticide to kill flying adult mosquitoes, those options are being looked at by a consultation advisory group working with the environmental health office.

On a national basis, Health Canada, too, will be working to educate people about what they can do as individuals to reduce their risk of coming infected. They will also be providing the most up-to-date information about the virus and surveillance results on the Health Canada Web site, at http://hc-sc.gc.ca.

Health Canada will be co-ordinating nationwide surveillance of the virus, which will involve tesing of dead birds-especially members of the crow family-suspected of being infected, as well as monitoring mosquito populations, and infection in horses and in humans.

The department will also be working with Canadian Blood Services and Hema Quebec to help ensure the Canadian blood supply is free of the virus. Private industry is working to develop a test for screening donated blood for the virus, and Artsob expects that test should be in place by July. In the meantime, the blood agencies are working to stockpile blood and blood products, gathering them from donors before this year's mosquito season begins.