West Nile virus is spread to people through the bite of an infected mosquito. Mosquitoes become infected by biting a bird that carries the virus. The virus does not spread directly from person to person. There is no evidence that the virus spreads from birds or animals to humans. In most otherwise healthy people WNV infection may cause mild illness resulting in symptoms such as swollen lymph glands, fever, headache, body aches or a mild rash before fully recovering.
Some people show no symptoms at all.
Very rarely, WNV causes swelling of the brain, or acute encephalitis, a serious illness that can cause permanent neurological damage and may be fatal. The elderly and immune compromised are at greatest risk of becoming seriously ill. To date, WNV has not been identified in any mosquito, bird or human in Canada. To date the virus has not been identified anywhere in the Province, however, it was identified in suburban Buffalo last year. Dead birds are the earliest and easiest means of monitoring the emergence of the virus.