The province of Manitoba issued new orders Thursday under the Environment Act to fog with malathion to kill adult mosquitoes in eight more communities, including Winnipeg.
The move is intended to kill Culex tarsalis mosquitoes, those most likely to carry the West Nile virus in Manitoba.
Provincial officials said the numbers of the mosquitoes are higher than usual for this time of year.
In addition to Winnipeg, orders have been issued for:
Details on when the fogging will take place will be available on the Manitoba Health website.
Two rounds of fogging have already been carried out in Altona, Stonewall, Winkler and West St. Paul after orders were issued last week.Further spraying would depend on the results of ongoing mosquito surveillance, officials said.
2 more cases of West Nile
Two new cases of West Nile virus have been reported in humans in Manitoba, bringing the total for the year to three, provincial officials alsosaid.
Details about the two new people diagnosed with the virus were not available, but officials said one case was identified through blood donation, while the second was identified in a clinic. The first case was diagnosedlast monthin a 53-year-oldblood donorfrom Lorette.
"Our information so far is that none of these three people have severe illness. None of them have been hospitalized. All of them are expected to have a complete recovery from the disease,"said Joel Kettner, the province's chief medical officer of health.
"As far as where they were exposed, we are investigating that now and don't have that information yet."
Most people who contract West Nile virus show no symptoms.Of those who do, most experience flu-like symptoms such as fever, headaches, fatigue and body aches.
The virus can cause the more serious West Nile neurological syndrome, which can result in weakness, paralysis, confusion, coma or— in rare cases— death.
The highest risk of human exposure to West Nile virus in Manitoba occurs in the last three weeks of July and the first three weeks of August. In 2006, there were 50 reported cases of the virus in people in the province.
Fogging could spark protests in capital
In recent years, provincial orders to fog with malathion have prompted protests and demonstrations in Winnipeg, where the city allows residents to register for 100-metre fog-free buffer zones around their homes.
In the past, thebuffer zoneshave beenlifted when a provincial order is in effect for the city.
Winnipeg has been fogging with malathion in recent weeks, butcity crews haverespected the roughly 1,500 buffer zones.
In 2005, protesters attempted to block fogging trucks leaving the city's truck depot and blocked a street in the Wolseley neighbourhoodwhen the trucks attempted to go down it.
Critics questionmalathion's effectiveness in killing adult mosquitoes and raise concerns about possible health effects from the insecticide.
According to Health Canada, the use of malathion for adult mosquito control in residential areas using ultra-low-volume application — or fogging — does not pose a health concern.
Provincial officials suggest people who wish to reduce their exposure to malathion should:
- Close doors and windows when fogging is underway.
- Turn off fans and air conditioners, or set them to exhaust settings.
- Remove clothing and toys from outdoor areas.
- Rinse household items and toys left outside before using them.
- Wash home-grown fruits and vegetables.