MOSQUITOES infected with West Nile virus have been discovered in provincially set traps in Morris, but so far there have been no reported human cases of the disease this summer in Manitoba.
Health officials held a media briefing Friday to warn the public the risk of exposure to the virus is expected to increase in the coming weeks. Last year, there were 39 confirmed human cases of West Nile in the province.
Dr. Margaret Fast, a provincial medical officer of health, said West Nile season has just begun and will be with us for another two months.
The Culex tarsalis mosquitoes that carry the disease thrive in hot, humid conditions. The trap containing the infected mosquitoes was discovered in the week of July 7. West Nile emerged a week earlier last year.
The rate of West Nile mosquito infection varies greatly from year to year. Last year, it was so severe in Portage la Prairie the province ordered the city be fogged. Buffer zones weren't allowed.
In 2011, no infected mosquitoes were discovered in Manitoba.
Manitoba Health sets mosquito traps in 29 communities to monitor for West Nile. Culex tarsalis mosquitoes so far are most prevalent in south-central Manitoba.
Fast said the majority of people who get bit by an infected mosquito have no symptoms. Those who develop symptoms may experience body aches, fever and flu-like illness.
More rare is the development of a severe neurological form of West Nile that affects the brain and the lining of the spinal cord.
"The more bites you have from an infected mosquito, the greater the likelihood of becoming infected," Fast said in urging Manitobans to take precautions against mosquito bites.
People can do that by wearing light-coloured, loose-fitting clothing that covers the arms and legs, using mosquito repellent, reducing the time they spend outdoors during peak mosquito hours and maintaining their window screens.