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.
September 19, 2025
Adult mosquito surveillance for West Nile virus, and weekly updates to the interactive map above have concluded for this season. New information about human cases and veterinary cases will be provided in this update and at: Surveillance Data for West Nile virus in Manitoba | Health | Province of Manitoba.
Two WNV-positive horses were reported since the last update, one in Prairie Mountain health region and one in Southern Health – Santé Sud. To date, one confirmed human WNV case (related to travel outside of Canada), 148 WNV-positive Culex tarsalis pools, 28 WNV-positive birds (mostly in Winnipeg) and 2 WNV-positive horses (PMH and SH-SS) have been identified in this season.
Although numbers are low, Culex tarsalis may continue to bite on warm afternoons and evenings, and at dusk until the first hard frost. Manitobans are encouraged to take precautions to 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.
