Weekly West Nile Virus Update


September 10, 2021

Two (2) additional WNV human cases were identified, one from the Southern Health Region and one from the Winnipeg Health Region. To date the province has identified five WNV human cases. Additional surveillance has detected seven (7) WNV positive horses and three (3) WNV positive birds. The horses were from the Interlake-Eastern (2), Prairie Mountain (3) and Southern (2) Health regions, while the WNV positive birds were collected from the Southern (1) and Winnipeg (2) Health Regions.

During the week of August 29 – September 4, 2021 no additional WNV positive Culex tarsalis mosquito pools were detected. Mosquito activity continued to decrease, with specimens collected in only 2/3rds of the sentinel communities. Preliminary data from the week of September 5 - 11, 2021 shows a further decrease in Cx. tarsalis activity.

With the cooler temperatures and shortening days, Cx. tarsalis activity has decreased. The risk of WNV exposure at this time is low, although not zero. Manitobans may consider taking precautions to further reduce their risk of exposure, particularly on warm days and in the early evening.

Manitobans can reduce the risk of mosquito bites and exposure to WNV by:

  • reducing the amount of time spent outdoors during peak mosquito hours between dusk and dawn;
  • using appropriate mosquito repellent;
  • wearing light-coloured, loose-fitting clothing with long sleeves and pant legs, and
  • maintaining door and window screens so they fit tightly and are free of holes. 

For WNV health concerns, contact your doctor or call:

Health Links – Info Santé
(Winnipeg) or toll-free 1-888-315-9257