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.
CHD staff will be able to respond to reports of dead birds starting on May 15th, 2001. If the virus is identified in Ontario personal protective measures to avoid mosquito bits should be taken. Turn over objects like wheel barrows and wading pools when not in use. Clean clogged roof gutters, particularly if leaves from surrounding trees have blocked the drains. Remove standing water under or around structures and on flat roofs.