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 26, 2024

Culex tarsalis mosquitoes were detected in all 21 trapping communities and all health regions in southern Manitoba during the week of July 14 to 20, 2024 (Week 29). Trap counts increased in all regions compared to Week 28 with the most significant increase in Southern Health/Santé Sud (from 112.4 to 283.3 Culex tarsalis / trap night).

Fifteen West Nile virus (WNV) positive Culex tarsalis mosquito pools were detected in Week 29 including positives in: Altona, Morden, Portage la Prairie, Ste. Anne, Winkler and Winnipeg. To date, 26 WNV-positive Culex tarsalis pools, eight WNV-positive birds and zero WNV-positive horses have been identified. Two confirmed WNV human cases were reported, both related to travel outside of Canada.

Warm temperatures forecast for the next week will continue to support increased Culex tarsalis activity. As of July 20, the risk of human exposure to WNV is Moderate. The risk level typically increases in July and August, which are historically the months with the highest risk of WNV.

Manitobans are encouraged to enjoy warm weather activities but take measures 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.