Portage la Prairie is one of two locations in Manitoba that will be sprayed for adult mosquitoes this week.

The Manitoba government has issued a ministerial order under the Environment Act to begin spraying because of high numbers of adult Culex tarsalis mosquitoes and evidence of infection with West Nile Virus. The other location is the town of Ste. Anne.

Depending on weather conditions, adult mosquito control occurs in the evening and at night and is expected to begin as early as tomorrow evening.

According to the province, the pesticide being used is unlikely to affect human health. DeltaGard 20EW was approved by Health Canada for use in 2017 and is classified as a reduced-risk pesticide. Individuals can minimize their exposure by taking the following precautions:

  • staying indoors during and immediately after spraying,
  • closing all doors and windows,
  • avoiding trucks while spraying is underway,
  • turning off fans and air conditioners or setting them at exhaust,
  • removing clothes and children’s toys from outdoor areas,
  • covering swimming pool surfaces,
  • washing any household items or toys left outside before using them, and
  • ensuring fruits and vegetables are washed.

Public health officials note the hot temperatures and dry conditions experienced this summer have created ideal conditions for Culex tarsalis, which are the mosquitoes capable of carrying the West Nile Virus. The risk for potential human exposure to West Nile Virus at this time is high, and this will likely continue as the province moves through the historical high-risk period in August. At this time, no human cases of West Nile Virus have been identified in Manitoba.

In order to reduce the risk of mosquito bites and potential exposure to the virus, Manitobans are encouraged to:

  • reduce the amount of time spent outdoors in peak mosquito hours during dusk and dawn;
  • use an appropriate mosquito repellent;
  • wear light-colored, loose-fitting clothing with long sleeves and pant legs;
  • maintain door and window screens; and
  • clean and empty yard items that collect water.

Between 2012 and 2018, there were 112 cases of West Nile Virus in Manitoba. Nearly 40 per cent of these cases were hospitalized and 11 required intensive care.