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 24, 2026

Adult mosquito surveillance conducted during the week of July 12 to July 18, 2026 (week 28) detected Culex tarsalis mosquitoes in 20 of 21 trapping communities in Manitoba. The number of mosquitoes per trap increased from the previous week and were significantly higher than the historical average for week 28.

13 West Nile virus (WNV) positive C. tarsalis mosquito pools were detected in Week 28, 1 in PMH, 8 in Southern Health/Santé Sud (including 4 in Ste. Anne and 3 in Altona) and 4 in Winnipeg Health regions. 7 WNV-positive wild birds were also reported. To date,16 WNV-positive C. tarsalis pools, 8 WNV-positive birds and zero WNV-positive horses have been identified. No human cases have been reported in the province this year.

Hotter, drier weather is supporting increased C. tarsalis activity. The risk of WNV exposure increased to moderate and is expected to increase further in July and August, which are historically the months with the highest risk of WNV.

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.