West Nile virus information

The West Nile virus is a virus that spreads by mosquitoes that have fed off the blood of infected birds. Once the mosquito has bitten an infected bird, it can transmit the virus by feeding off another animal. Most birds do not become ill after being infected by the virus but birds form family of the Crows is especially susceptible to it and often die as a result of inflammation of internal organs. For this reason, dead birds such as crows, magpies, ravens, and blue jays have been chosen as indicators of the presence of West Nile virus in an area. Although birds are the typical host infected by the virus, it can also infect amphibians, domestic mammals (especially horses), apes and humans.

The virus was originally detected in the West Nile District of Uganda in 1937. Outbreaks have been recorded in parts of Africa, West Asia, Eastern Europe, the Middle East and North America. The first North American case of West Nile Virus was discovered in New York City in 1999 and has spread considerably since then. In Canada, the first infected bird was found in Ontario in 2001 and the first human case was confirmed in September 2002.

It is important to note that the risk of serious health repercussions related to West Nile virus is very low for most people. Children are not particularly vulnerable and older people as well as people with weaker immune systems have higher health risks. Symptoms vary depending on the person infected and can include, fever, headaches and body aches in mild cases and encephalitis (inflation of the brain) in more serious cases.

Many measures have been put in place to reduce the risk of being infected by the West Nile virus such as public awareness campaigns and pesticide application. There are two major problems with pesticide application:

1. Non-specific pesticides harm people as well as mosquito predator populations who naturally help to control the mosquito population.

2. With the continued application of pesticides, targeted species become resistant to this pesticide.

Sources and Links

Canadian Coalition for Health and Environment

Canadian Cooperative Wildlife Health Centre

Government of New Brunswick – Department of Health and Wellness

Health Canada - West Nile Virus

National Pesticides Information Center (USA)