Weekly West Nile Virus Update
The WNV Story Map may not always be updated at the same time as the WNV Surveillance Statistics website and the Weekly Update. Please check back later if the Story Map does not align with the Weekly Surveillance Statistics and Weekly Update.
July 4, 2025
Adult mosquito surveillance conducted during the week of June 22 to 28, 2025 detected Culex tarsalis mosquitoes in 3 of 21 trapping communities in southern Manitoba. To date, no positive West Nile virus (WNV) surveillance indicators have been identified anywhere in the province. One confirmed and one probable WNV human cases have been reported, both related to travel outside of Canada.
Dry conditions this spring have limited mosquito larvae development, however recent rain events in most of the province, combined with warmer temperatures will likely result in higher numbers of mosquitoes. Culex tarsalis activity is low and the current risk of WNV exposure is minimal, but this will increase as we enter the historical high-risk period (i.e. July – August).
Manitobans are encouraged to enjoy outdoor activities and 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.
Manitobans can also reduce the number of mosquitoes around their home by eliminating standing water. To reduce standing water:
- clean eaves troughs and regularly empty bird baths and other items that might collect water,
- ensure rain barrels are covered with mosquito screening or are tightly sealed around the downspout,
- clear yards of old tires or other items that collect water, and
- improve landscaping to prevent standing water around the home.
