Mosquitoes carrying West Nile Virus are starting to show up in Manitoba.

Manitoba Health is reporting that Culex Tarsalis mosquitoes carrying the virus were collected from the Rural Municipality of West St. Paul during the week of June 18 to 24. This is the first mosquito pool that has tested positive in Manitoba this year. 

The first positive pool was detected earlier than normal this year, likely due to warmer temperatures in southern Manitoba this spring and summer. There have only been three other times in the last 20 years where a positive mosquito pool was detected during this week.

The risk of West Nile Virus infection depends on various factors including time of year, number and location of infected Culex Tarsalis mosquitoes, and the number of days with sufficient heat. Risk of exposure to West Nile Virus is currently low but likely to increase in the coming weeks, as the highest risk period is historically in July and August. Manitobans are reminded that it takes just a single bite from an infected mosquito to contract West Nile Virus.

While most people who are infected will develop mild or no symptoms, some can develop severe symptoms that can result in hospital stays and even death. Recovery from West Nile Virus infection, particularly severe symptoms, can take months or years.

While Manitobans are encouraged to enjoy outdoor activities, it is critical to reduce the risk of mosquito bites and potential exposure to West Nile Virus by:

  • reducing the amount of time spent outdoors during peak mosquito hours between dusk and dawn;
  • using an appropriate mosquito repellent;
  • wearing light-coloured, loose-fitting clothing with long sleeves and pant legs;
  • maintaining door and window screens; and
  • cleaning and emptying yard items that collect water.

In 2022, there were seven cases of West Nile Virus in Manitoba, and five of those were hospitalized. No confirmed human cases of West Nile Virus have been identified in Manitoba yet this year.