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 13, 2024
No new human WNV cases were reported this week. Four confirmed and one probable WNV human cases have been reported in 2024, including two that were related to travel outside of Canada. Fifteen WNV-positive birds and one WNV-positive horse have also been identified this season.
No WNV-positive Culex tarsalis mosquito pools were detected in Week 36. To date, 125 WNV-positive Culex tarsalis pools have been identified, with the majority in the Southern Health – Santé Sud and Winnipeg health regions.
Culex tarsalis mosquitoes were only detected in 8 of 21 trapping communities in southern Manitoba during the week of September 1 to 7 (Week 36). C. tarsalis counts decreased significantly in all regions. The Southern Health – Santé Sud region had the highest counts (0.7 Culex tarsalis / trap night).
Adult mosquito surveillance has now concluded for 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 minimize their exposure to mosquito bites. This includes:
- 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.
