Questions and Answers about West Nile Virus

Q: What is West Nile Virus?  Where did it come from?

A: West Nile Virus (WNV) is passed between birds and mosquitoes. It can infect other animals and was first found in a human in the West Nile Valley, Uganda, in 1937.  It has since spread to the rest of Africa, the Middle East, Europe, and now, North America.

Q: How does it spread?

A: The virus is spread when mosquitoes bite birds and infect them with the virus. The birds get ill, "amplifying" (increasing) the number of viruses, and the virus is then spread to new mosquitoes when they bite the bird.  Sometimes the virus "spills over" into other species, such as horses.  Humans can be infected too.

Q: What are the symptoms?

A: About 8 in 10 people that are infected will have no symptoms.  Another 2 in 10 will have what is called West Nile Fever - headache, fever, aches, malaise and a rash.  This is a mild illness that lasts for about 3 to 6 days.  Approximately 1 person in 150 who are infected will develop more serious symptoms, which can include encephalitis (inflammation of the brain) or meningitis (inflammation of the lining around the brain).  Some of those people will have long lasting or permanent side effects.  Less than 1 in 1000 who are infected will die.

Q: How fast is it spreading?

A: It first appeared in New York in 1999.  By 2001 it had spread to the Mississippi Valley, and was found in Ontario.  By the end of 2002 it had spread to the West Coast, and was found in Washington State.  In Canada it has come as far west as Saskatchewan, but has not been found in Alberta or BC yet.  We expect to see it in BC this year.

Q: How is it found?

A: The "Corvid" family of birds gets very ill from WNV.  These include crows, ravens, magpies, and jays, and are considered "indicators" of the virus. Testing of dead Corvids and mosquito samples for WNV will tell us if the virus is present in an area.

Q: Is testing happening here?

A: Yes.  Testing of Corvid and mosquito specimens will be done throughout Interior Health during mosquito season.  Doctors have also been told to watch for West Nile Fever as a possibility in patients that present with similar symptoms.

Q: What should I do if I find a dead crow, raven, magpie, or jay?

A: Even though mosquitoes spread WNV, don't touch dead birds with your bare hands (you should not touch any dead animal with your bare hands).  Report any dead Corvids, that are not decaying, injured, or found by the road to 1-866-300-0520. If the "Surveillance Coordinator" for your area can pick up the specimen, follow the directions they give you. If not, they will direct on disposal, or listen to the voice message.

Q: How can I protect myself from WNV?

A: You can do several things to protect yourself from mosquito bites:

• Wear light coloured, baggy clothing, with long sleeves and pants
• Use an insect repellant containing DEET.  Follow the label instructions, especially for children - do not use on children under 6 months old (10% max. concentration for children, 30% for adults)
• Stay indoors from dusk to dawn
• Avoid forested areas in the daytime
• Put screens on doors and windows

Q: If mosquitoes spread WNV, how can I keep mosquitoes away?

A: About 12 types of mosquitoes in BC can spread WNV.  You can do a lot to keep them from breeding on your property:

• Empty or cover any containers of water, no matter how small: saucers under plant pots, wheelbarrows, buckets, rainbarrels, rain gutters, swimming pool covers, bird baths (change the water at least twice per week), old tires
• Drain any standing water in your yard
• Fill in hollow areas
• Cut your grass regularly to remove places for mosquitoes to rest
• Turn your compost over often
• If you have a pond, put fish in it or add an aerator/fountain