HealthLink BC File #88, July 2012

West Nile Virus





What is West Nile Virus?

West Nile virus (WNV) is a disease usually spread between birds by mosquitoes. Mosquitoes can become carriers of the virus after biting birds infected with the virus. It is possible for people, horses and other animals to become infected if they are bitten by a mosquito carrying the virus.

What are the symptoms of West Nile Virus?

About 80 per cent of people infected with WNV will not get sick. About 20 per cent of people will have a mild to moderate illness that starts 3 to14 days after being infected.

Symptoms may include fever, headache, body aches, fatigue, swollen lymph glands, and sometimes a rash on the body. These symptoms generally last about 1 week, but they can last much longer.

In less than 1 per cent of people, WNV infection can result in more serious illnesses such as meningitis (inflammation of the lining of the brain), encephalitis (inflammation of the brain), or polio-like paralysis. People who have one of these more serious illnesses may also have high fever, severe headache, confusion and weakness.

In very rare cases, WNV infection can result in death. If you develop a severe headache or neck stiffness for which you cannot find a cause, or other symptoms of WNV, contact your health care provider.

What is the treatment for West Nile Virus?

Many of the symptoms and complications of WNV can be treated, although there is no specific treatment, medication or cure for the infection. Most people who are infected with WNV get better, but it may take a long time to recover fully. There is no human vaccine for WNV at this time.

Where is West Nile Virus found?

WNV is found in many parts of Africa, Western Asia and the northern Mediterranean area.

The first outbreak of WNV in North America was in New York City in 1999. Since then it has spread to most states in the U.S. and across most provinces of Canada, including B.C.

What is the risk of West Nile Virus in B.C.?

There are many species of mosquitoes, but only a small number of these can carry and transmit the virus. Some of these are present in B.C.

Once the virus enters a community, the risk of infection continues to grow as it gets later in summer and especially if it remains quite hot.

How can I protect myself?

Any activity that prevents mosquitoes from biting or breeding will help to reduce the risk of infection with WNV. There are many simple things that you can do to protect yourself:

Backyard pools can be a big source of mosquitoes and should be maintained regularly to prevent mosquito growth.

What is being done to watch for WNV?

Many types of birds can be infected with WNV. However, crows, ravens, jays and magpies, are very sensitive and likely to die from the virus. Officials test dead birds to find out if WNV has moved into an area.

Some areas of B.C. have programs in place for collecting and testing samples of dead birds.

Sightings can be reported on the BC Centre for Disease Control website at www.bccdc.ca/westnile.

While birds reported on the website will not be picked up for testing, health authorities will be tracking the number of dead birds reported to help assess the risk of WNV in an area.

Could handling a dead bird infect me?

The risk of infection from handling birds is very low; however, you should not use your bare hands to handle wild birds or other animals (dead or alive). If you need to move a dead bird, the following precautions should be taken:

For more information


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