West Nile virus (WNV) is a neurotropic flavivirus that has emerged globally as a significant cause of viral encephalitis. Infection of humans is associated with a febrile illness that can progress to a lethal encephalitis with symptoms including cognitive dysfunction and flaccid paralysis. Seroprevalence studies suggest that while the majority of WNV infections are asymptomatic, approximately 20 to 30% of infected individuals develop flu-like clinical manifestations characterized as WNV fever.
Human cases of West Nile virus infection have been reported in parts of British Columbia, Alberta, Saskatchewan, Manitoba, Ontario and Quebec. The Government currently has data for West Nile virus human clinical cases reported between 2005 and 2014: ukon Territory, New Brunswick, Prince Edward Island and Nova Scotia. 2005: 225 cases, 2006: 151 cases, 2007: 2215 cases, 2008: 36 cases, 2009: 13 cases, 2010: 5 cases, 2011: 101 cases, 2012: 428 cases, 2013: 115 cases, 2014: 21 cases.
The diagnosis of West Nile virus infection is confirmed with a blood or cerebrospinal fluid test. There is no specific treatment for West Nile virus infection. Intensive supportive therapy is directed toward the complications of brain infections. Anti-inflammatory medications, intravenous fluids, and intensive medical monitoring may be required in severe cases.
The Government of Alberta through Alberta Health and Wellness has the mandate to determine how many Albertans have been infected with West Nile virus since it spread to our province during the spring and summer of 2003. This information will help the province plan its educational prevention programs as well as understand the impact the virus has had thus far.