Because of high numbers of adult Culex tarsalis mosquitoes, and evidence of a high rate of mosquito infection with West Nile virus (WNV) in the City of Winkler, the Manitoba government is issuing a ministerial order under the Environment Act to begin spraying for adult mosquitoes.
In addition to the City itself, adult mosquito control will take place in an approximately three kilometre extended zone around the city. This includes the communities of Reinfeld, Chortitz and Schanzenfeld.
According to a news release issued Thursday afternoon by the Province, public health officials noted recent warm, humid conditions were ideal for Culex tarsalis mosquitoes that can spread the West Nile virus.
Risk "very high" in Winkler and area
"The risk for potential human exposure to WNV at this time is high in the Southern Health-Santé Sud region, and is considered very high in Winkler and surrounding area," noted the news release. "This risk will likely continue during the historical high-risk period (mid-July to mid-August)."
According to the Province, at this time, no locally acquired human cases of West Nile virus have been confirmed in Manitoba.
The product that will be used is DeltaGard 20EW, which is classified as a reduced-risk pesticide. When applied using ultra-low volume methods and as per label directions, DeltaGard 20EW is unlikely to affect human health.
Control operations timeline
Control operations are expected to take place overnight between Friday, August 8th and Saturday, August 9th, and overnight between Monday, August 11th and Tuesday, August 12th. Fogging will proceed weather permitting, will not occur if the temperature is expected to drop below 13 C, there is excessive wind or precipitation.
The treatment times and area map are available, here.
West Nile Virus is a mosquito-borne virus that can cause severe illness including encephalitis (swelling of the brain) and can sometimes result in long-term complications and death. It only takes a single bite from an infected mosquito to contract WNV.
More information about West Nile virus can be found, here.