August 4, 2021
West Nile Virus Bulletin #2
The Manitoba government is issuing a ministerial order under The Environment Act to begin spraying for adult mosquitoes with DeltaGard 20EW® because of high numbers of adult Culex tarsalis mosquitoes and evidence of infection with West Nile virus (WNV). The order will cover the Rural Municipality of West St. Paul and the City of Winnipeg.
Subject to weather and site conditions, adult mosquito control will take place in the areas of, but not limited to, the Rural Municipality of West St. Paul and the City of Winnipeg’s insect management areas 43, 44, 48, 49 and 51.
Adult mosquito control occurs in the evening and at night and is expected to begin Thursday evening, weather conditions permitting.
Public health officials note the hot temperatures and dry conditions experienced this summer have created ideal conditions for Culex tarsalis mosquitoes that carry WNV. The risk for potential human exposure at this time is high, and this will likely continue as we move through a historical high-risk period in August. At this time, no human cases have been identified in Manitoba.
While Manitobans are encouraged to enjoy warm weather outdoor activities, it is strongly recommended people reduce their risk of mosquito bites and potential exposure to the virus. Key prevention measures include:
• reducing the amount of time spent outdoors in peak mosquito hours during dusk and dawn;
• using an appropriate mosquito repellent;
• wearing light-colored, loose-fitting clothing with long sleeves and pant legs;
• maintaining door and window screens; and
• cleaning and emptying yard items that collect water.
Taking precautions against WNV helps protect the health-care system, which continues to see strain due to COVID-19. Between 2012 and 2018, there were 112 cases of WNV in Manitoba. Nearly 40 per cent of these cases were hospitalized and 11 required intensive care.
Approved by Health Canada for use in 2017, DeltaGard 20EW® is classified as a reduced-risk pesticide. When applied using ultra-low volume methods and as per label directions, it is unlikely to affect human health. For more information, visit: https://www.gov.mb.ca/health/publichealth/factsheets/deltagard.pdf.
However, 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.
More information about West Nile virus, including prevention, symptoms, weekly average trap counts of Culex tarsalis mosquitoes, fact sheets, posters and information for municipalities and health-care providers, is available at www.gov.mb.ca/health/wnv/.
Manitobans can also contact Health Links–Info Santé at 204-788-8200 or at 1-888-315-9257 (toll-free) for more information.
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