Manitoba Health reports an increase in the number of adult Culex tarsalis mosquitoes trapped during the week of July 25 throughout southern Manitoba, compared to the previous week.
Samples of Culex tarsalis from adult mosquito traps in the towns of Steinbach and Beausejour tested positive for West Nile virus. The numbers of infected mosquitoes are estimated to be relatively low and no adult mosquito control has been recommended at this time. So far in 2010, a total of four positive mosquito samples have been found.
Preliminary trap information for the week of Aug. 1 shows the number of Culex tarsalis mosquitoes has declined slightly throughout southern Manitoba. It is anticipated that more positive mosquitoes may be identified in additional communities in the next few weeks. In previous years, the peak risk period for human exposure to West Nile virus has been the last two weeks of July and the first three weeks of August.
To date, no human cases of West Nile virus have been identified in Manitoba in the 2010 season.
