Manitoba Health reports there was a slight decrease in the numbers of adult Culex tarsalis mosquitoes trapped throughout southern Manitoba during the week of July 11 compared to the previous week. However, preliminary trap information for this week indicates the numbers of Culex tarsalis mosquitoes are increasing throughout southern Manitoba, with some communities in the southwestern part of the province showing large increases.
None of the mosquitoes collected during the week of July 11 tested positive for West Nile virus. So far in 2010, two positive mosquito samples have been found. More positive samples are likely to be identified in additional communities within the next few weeks.
A risk of being infected with West Nile virus exists throughout southern Manitoba at this time. The risk of infection is expected to increase in the coming weeks, particularly if there is warm weather. Mid-summer is usually the highest risk period for exposure to West Nile virus. Taking measures to prevent mosquito bites and reducing standing water around homes can help minimize the risk of West Nile virus exposure.
To date, no human cases of West Nile virus have been identified in Manitoba in the 2010 season.
