September 29, 2005
Based on recent mosquito surveillance, the time of year and the life cycle of the Culex tarsalis mosquito, the current risk of becoming infected with West Nile virus in Manitoba is considered low. Nuisance mosquitoes and a few Culex tarsalis mosquitoes may remain active if warmer weather continues.
Mosquito surveillance in the sample traps will end this week.
Since last week’s update, five more Manitobans have tested positive for West Nile virus. One case under investigation was determined not to be a recent Manitoba case. This brings the total number of West Nile virus cases in 2005 to 55.
Following investigations by public health officials, 51 human cases have been classified:
10 cases are West Nile neurological syndrome;
38 cases are West Nile non-neurological syndrome; and
three identified by Canadian Blood Services are asymptomatic cases of West Nile virus.
The 51 classified cases were found in seven regional health authorities in southern Manitoba:
Assiniboine Regional Health Authority – 15;
Winnipeg Regional Health Authority – 14;
Central Regional Health Authority – 12;
South Eastman Regional Health Authority – three;
Interlake Regional Health Authority – three;
Brandon Regional Health Authority – three; and
North Eastman Regional Health Authority – one.
This will be the last West Nile virus update for 2005. Any additional information on human cases will be posted on the WNV website weekly (Thursdays) at http://www.gov.mb.ca/health/wnv.
Analysis of information from this year’s program continues. Information regarding specific plans for next year's West Nile virus program will be available in spring 2006.
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