West Nile virus was first identified in the Uganda region of Africa in 1937 and more recently reported in North America, when it caused an outbreak of human disease in New York in 1999. The virus is spread by mosquitoes that have fed on the blood of infected birds (commonly crows, sparrows, jays, and ravens). It can also be transmitted through receipt of infected blood products, organ/tissue transplants, and via breast milk. (As of July 2003 Canadian Blood Services has had a test that screens every blood donation for West Nile virus.) There is no evidence that an individual can get the virus from an infected person, or that animals (such as cats and dogs) are affected by the virus and can spread it to humans.

What are the symptoms of West Nile virus infection?

Most people infected with the virus have no symptoms at all or only mild symptoms that develop 3 to 14 days after the mosquito bite. Once infected, you may develop flu-like symptoms, such as muscle aches or joint pain, fatigue, headache, fever, sensitivity to lights, swollen glands, and a rash. In rare cases (less than 1 percent), the illness can become quite serious and lead to encephalitis (inflammation of the brain) or meningitis (inflammation of the tissues surrounding the brain). This is more common in older people or those with weaker immune systems or long-term illnesses.

The risk of being bitten by an infected mosquito is very low, and the chances of becoming seriously ill are even lower. However, anyone who is bitten in an area where West Nile virus infection has been found in dead birds, mosquitoes, or horses may be at risk of infection. In most parts of Canada, including Nova Scotia, the risk of being bitten by a mosquito that carries the virus is greatest from July until early September.

There are many things you can do in your own yard to keep the mosquitoes away.

· Reduce the number of mosquitoes around your home by getting rid of stagnant water, which is a breeding ground for mosquitoes. Be sure to drain pool covers and under plant pots, recycling and garbage bins. Also, keep your grass mowed and free of tall weeds and bushes.

· Remove old, unused items from your yard (e.g. old tires), where water has a tendency to collect. Turn over your compost pile every few days.

·Empty and change the water in wading pools, pet bowls, birdbaths, and livestock watering tanks twice a week. If you have an ornamental pond, consider getting fish that will eat mosquito larvae (eggs).

·Cover rain barrels with window screening.

·Clean out eavestroughs regularly to prevent clogs that can trap water.

To protect yourself from mosquito bites:

·Limit your time outdoors at dusk and dawn (gardeners beware!), when mosquitoes are most active.

·Wear long-sleeved clothing, socks, and a hat when mosquitoes are active. Mosquitoes are less attracted to light-coloured clothing.

·Make sure your door and window screens fit tightly and have no holes. Don’t leave unscreened doors and windows open.

· Use insect repellant containing DEET (N, N-diethyl-m-toluamide) when outdoors. The concentration of DEET should be no greater than 30 percent for adults and 10 percent for children. The concentration correlates with protection time (that is, 30 percent DEET is effective for about 6 hours, while 10 percent DEET provides protection for about 3 hours). Check with your pharmacist for more detailed information. DEET should not be used on infants less than 6 months. Mosquito netting around strollers or carriages can be used instead. Avoid spraying directly on skin if possible or very sparingly. Spray on clothing, footwear, and hats instead, avoiding the eyes and hands. For children between 6 months and 2 years, DEET can be used once a day in concentrations of 10 percent or less, avoiding the face and hands. Health Canada also advises that DEET should be used no more than three times daily for children between 2 and 12 years. Citronella oil repellants are effective for less than one hour. Citronella candles are only effective at repelling mosquitoes during low wind conditions and at very close range. Fabric softener sheets, bananas, garlic, Vitamin B1, and bath oils are all unproven, ineffective mosquito repellants.

How do I report a dead bird?

The Department of Natural Resources (DNR) is collecting certain types of dead birds in order to track West Nile virus in Nova Scotia. If you find a dead crow, jay, or raven, you can report the siting to the local office of the Department of Natural Resources. Do not handle the bird with bare hands. Check with DNR for details on how to safely dispose of the bird if it can’t be tested.

For more information, see the Department of Health website www.gov.ns.ca/health/westnile/wnile.htm and Health Canada website http://www.hc-sc.gc.ca/pphb-dgspsp/wnv-vwn/.

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