Manitoba Health is reporting the first confirmed human case of West Nile virus (WNV) in 2023, along with three other probable WNV cases currently under investigation.

The confirmed case is 40 to 49 years of age and lives in the Winnipeg Regional Health Authority. The individual experienced neurological symptoms and was hospitalized. They were most likely exposed to WNV sometime in late June to early July. A public health investigation has been completed. More information about the other cases will be posted on Manitoba Health’s WNV web page if they are confirmed to be infected with WNV.

In 2022, there were seven cases of WNV in Manitoba, and five of those cases required hospitalization.

Manitobans are reminded that weather conditions have been favourable for Culex tarsalis mosquitoes, the species that carries WNV. Due to current mosquito trap counts, WNV-positive mosquito pools, and weather conditions, the risk of exposure to WNV is currently considered to be high.

Manitobans are reminded that a single bite from an infected mosquito can transmit WNV. While most people who are infected will develop mild or no symptoms, some can develop severe symptoms that can result in hospitalization and even death. Recovery from WNV infection, particularly severe symptoms, can take months or years.

Culex tarsalis mosquitoes typically feed between dusk and dawn and often go unnoticed when biting. While Manitobans are encouraged to enjoy outdoor activities, it is critical to reduce the risk of mosquito bites and potential exposure to WNV by:

  • reducing the amount of time spent outdoors during peak mosquito hours between dusk and dawn;
  • using an appropriate mosquito repellent;
  • wearing light-coloured, loose-fitting clothing with long sleeves and pant legs;
  • maintaining door and window screens; and
  • cleaning and emptying yard items that collect water.

To date, 45 pools of mosquitoes infected with WNV have been identified in Manitoba this year, with eight pools identified the week of Aug. 13 to 19. Weekly WNV updates with regional surveillance information and information about confirmed human cases are posted at www.gov.mb.ca/health/wnv/stats.html.

For more information about prevention, symptoms, fact sheets, posters and information for municipalities and health-care providers, visit www.gov.mb.ca/health/wnv/. Manitobans can also contact Health Links-Info Santé at 204-788-8200 or at 1-888-315-9257 (toll-free) for more information.