Manitoba Health reports one mosquito sample tested positive for West Nile virus during the week of Aug. 22 to 28, in Morris. So far this year, a total of 20 positive mosquito samples have been found. Based on the current level of infected mosquitoes, adult mosquito control is not being recommended at this time.
The number of adult Culex tarsalis mosquitoes trapped during the week of Aug. 22 decreased compared to the previous week. Preliminary numbers for the week of Aug. 29 show the number of Culex tarsalis in traps continue to decrease.
The risk of human exposure to West Nile virus is decreasing but the potential for exposure is still present in southern Manitoba. The risk is expected to continue to decline in the weeks ahead. As daytime and evening temperatures become cooler, Culex tarsalis mosquitoes may become more active during the day and early evening, with reduced activity overnight when temperatures are cool.
To date, no human cases of West Nile virus have been identified in Manitoba in the 2010 season.
