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 12, 2024

Average numbers of Culex tarsalis mosquitoes were detected in all 21 trapping communities and in all health regions in southern Manitoba during the week of June 30 to July 6, 2024 (Week 27). Preliminary data for Week 28 shows a notable increase of C. tarsalis in several communities.

Two West Nile virus (WNV) positive Culex tarsalis mosquito pools were detected in Week 27, both in Morden. To date, two WNV-positive Culex tarsalis pools, six 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.

Hotter temperatures forecast for the next week will likely result in increased Culex tarsalis activity. As of July 6 the risk of human exposure to WNV increased from minimal to low. The risk level is expected to increase 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.