B. C. officials vigilant for West Nile virus
Public health officials in B. C. are watching the province closely for signs of West Nile virus given the skyrocketing infection rates south of the border and the year’s first reported case in Alberta on Tuesday.
There have been no cases of the virus in B. C. this year, but there has been a dramatic increase in the number of mosquitoes that can carry the disease in the last few weeks due to the hot weather, said Dr. Bonnie Henry, a communicable disease expert at the BC Centre for Disease Control.
“That does make us ... concerned because the more of those mosquitoes that are around, the higher the probability that there’ll be infected ones around as well,” Henry said, adding that this time of year is the highest risk period for the disease, which is transmitted from birds to people through the bite of an infected mosquito.
Health officials in B. C. are testing mosquitoes and crows, which are especially sensitive to the disease and can serve as an early warning that West Nile has moved into an area, Henry said, but so far all the tests have come back negative.
West Nile virus infections in the United States have jumped more than 60 per cent in the past week in what federal officials say is one of the country’s biggest outbreaks of the disease.
The U. S. Centers for Disease Control said on Wednesday that 1,118 cases and 41 deaths had been reported so far this year, up from fewer than 700 cases and 26 deaths just one week ago. Texas has been particularly hard hit, with aerial pesticide spraying underway in Dallas and the surrounding area.
In Canada, Ontario is reporting 49 confirmed or probable cases as of last week, with 30 in Toronto alone. There have been five reported cases in Manitoba, two in Quebec and one each in Saskatchewan and Alberta. B. C.’ s last confirmed case was in 2010, Henry said. In the past, the disease has been detected in the Southern Okanagan and the Fraser Valley.
About 80 per cent of people who contract West Nile experience no symptoms because the body’s immune system is able to fight it off, Henry said. The other 20 per cent experience headaches and muscle aches accompanied by a fever, symptoms which can last several weeks.