Manitoba Health, Healthy Living and Seniors has identified the first human case of West Nile virus (WNV) this year. The individual is a male in his 30s from the Winnipeg Regional Health Authority, who experienced neurological symptoms. He was most likely exposed to WNV in the Winnipeg area in midsummer. The investigation is ongoing.
The department is also reporting a male from the Prairie Mountain Health region in his 60s has tested positive for WNV. His exposure to WNV is believed to have taken place prior to the 2014 season.
The current risk for human exposure to WNV is low.
In Manitoba, the main carrier of the virus is the Culex tarsalis mosquito. The department’s surveillance program found this season’s first Culex tarsalis mosquito samples infected with WNV during the week of July 20th.
WNV can cause severe illness (West Nile virus neurological syndrome) including encephalitis, an inflammation of the brain. The severe illness can be life-threatening and may result in long-term disability. Since 2003, the annual number of severe cases of WNV in Manitoba has ranged from one to 72; WNV-related deaths have ranged from none to four per year.
More people develop a milder illness (West Nile virus Non-neurological Syndrome) with symptoms such as fever, headache, fatigue, body aches and rash.
Most people infected with WNV have no symptoms and do not become ill.
There is no vaccine or specific treatment for WNV. Milder symptoms of WNV Non-neurological Syndrome usually resolve without medical care. Anyone experiencing severe symptoms (ex: persistent high fever, muscle weakness, headache) should seek medical attention promptly for diagnosis and care. For more infectious disease news and information, visit and “like” the Infectious Disease News Facebook page