July 31, 2012
West Nile Virus Update #3
– – –Two Human Cases of West Nile Virus Infection Identified
Manitoba Health has been notified by Canadian Blood Services of two blood donors who tested positive for West Nile virus (WNV). Both individuals are in their 40s, reside in the Winnipeg Health Region and donated blood on July 26 and 27. A blood-screening test identified the individuals had the virus. Initial reports indicate that one of the individuals reported mild symptoms and the other had no symptoms.
Further investigation is underway to confirm when and where the exposures to the WNV may have taken place.
Recent hot, humid conditions have created ideal conditions for the development of Culex tarsalis mosquitoes, biting activity and the transmission of West Nile virus. Manitoba Health is reporting a high risk of exposure to WNV throughout southern Manitoba and Manitobans are urged to take special care to reduce the risk of mosquito bites and WNV, even when there do not appear to be many mosquitoes.
Although there is an elevated risk of exposure to WNV and precautions are encouraged, an adult mosquito control program is not needed at this time. However, Manitoba Health will continue to monitor the situation on an ongoing basis.
So far in 2012, mosquito samples positive for West Nile virus have been identified from
14 communities across southern Manitoba.
To reduce the risk of mosquito bites and West Nile virus, Manitobans are encouraged to:
- reduce the amount of time spent outdoors during peak mosquito hours between dusk and dawn;
- use appropriate mosquito repellent;
- wear light-coloured, loose-fitting clothing; and
- maintain door and window screens so they fit tightly and are free of holes.
Manitobans can also reduce the number of mosquitoes around their home by eliminating standing water. To reduce standing water:
- clean eavestroughs and regularly empty bird baths and other items that might collect water,
- ensure rain barrels are covered with mosquito screening or are tightly sealed around the downspout,
- clear yards of old tires or other items that collect water, and
- improve landscaping to prevent standing water around the home.
Manitobans can check the West Nile virus website regularly for up-to-date data and information including weekly average trap counts of Culex tarsalis mosquitoes by regional health authority.
For more information about West Nile virus, contact Health Links–Info Santé at 204-788-8200 or
1-888-315-9257 (toll-free); or visit the province’s West Nile virus website at: www.gov.mb.ca/health/wnv.
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