July 06, 2004

·         As of today, three crows have tested positive for West Nile virus in Manitoba this year: in Winnipeg, Parkland and most recently in the Assiniboine Regional Health Authority. As of today, 209 birds have been submitted for testing for West Nile virus (WNV) in Manitoba. The bird surveillance program began May 5.

·         There have been no human cases of West Nile virus diagnosed in Manitoba in 2004.

·         Manitobans can help detect the arrival of West Nile virus in their area by reporting dead crows, blue jays, magpies or ravens to Health Links-Info Santé at 788-8200 in Winnipeg (outside of Winnipeg toll-free 1-888-315-9257). Links to pictures of these birds can be viewed under bird surveillance at http://www.gov.mb.ca/health/wnv.

·         West Nile virus identified in birds from the crow family provides an early indication of West Nile virus in an area. It is likely that birds will be identified soon in other regional health authorities in southern Manitoba. Once testing has demonstrated the presence of WNV in a specific area, no further birds from that area are required for testing.

·         Few species of mosquitoes were found infected with West Nile virus in Manitoba in 2003. The species of primary interest for human risk, Culex tarsalis, depends on hot weather to build up to high numbers and is often present in drier weather. This and related species are most often found in standing water that may be polluted with organic material. Low numbers of Culex tarsalis are being detected in a few communities in southern Manitoba at this time.

·         Most nuisance species of mosquitoes depend on wet conditions associated with frequent rainfall and are usually found in relatively clean, fresh water from rainfall or snow-melt pools. Current mosquito surveillance shows the large numbers of mosquitoes in Manitoba at this time are nearly all nuisance mosquitoes.

·         While the risk of West Nile virus is expected to increase over the summer, at this time, the risk of human infection with West Nile virus in Manitoba is considered very low.

·         Remember, Manitobans can reduce mosquitoes by emptying standing water that may collect in backyards, old tires, children's toys, pet bowls, wading pools or stagnant ponds, or under flower pots.

·         Manitobans can reduce the risk of mosquito bites by:  wearing light-coloured, loose-fitting clothing; using mosquito repellent containing DEET; and reducing the amount of time spent outdoors during peak mosquito hours between dusk and dawn.

·         Public information about West Nile virus is available by calling Health Links-Info Santé at 788-8200 in Winnipeg or toll-free at 1-888-315-9257. Additional information is available on the Manitoba Health website at http://www.gov.mb.ca/health/wnv, which will be updated with surveillance data weekly.

·         Regular updates on West Nile virus will occur on Thursdays, beginning July 15.

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