Aug. 13, 2012, 10:46 a.m.
An unprecedented number of mosquitoes that can carry the West Nile virus are being found in B.C. traps - but none has tested positive yet for the potentially fatal disease.
The B.C. Centre for Disease Control issued an advisory earlier this month on the increased risk of West Nile that comes with warmer temperatures.
"The number of Culex mosquitoes we're seeing this year is higher than we've ever seen before in B.C.," said Dr. Bonnie Henry of the BCCDC on Tuesday. "That's been a bit of a worry for us."
Hundreds of the Culex variety of mosquito that can carry West Nile have been found in traps this summer, she said.
"In the past, we've had one or two or three [Culex mosquitoes per trap]," she said.
But this year as many as 1,000 Culex mosquitoes have been counted among the 16,000 to 17,000 mosquitoes per trap.
"Again, we haven't had any carrying West Nile virus that we've found yet but we're still watching for it," she said.
Symptoms such as fever, fatigue, headaches and swollen lymph glands will manifest in about 20 per cent of people infected with West Nile. But about one in 150 cases will result in more severe illness such as inflammation of the brain, or polio-like paralysis, which can be fatal.
West Nile cases have been recorded in Saskatchewan, Manitoba and Ontario, as well as south of the border in Idaho, Oregon and California.
The areas of most concern in B.C. are the southern Okanagan and the Fraser Valley.
"If people are travelling, they need to think of mosquito protection," said Henry.
The West Nile threat is likely to continue through August along with the warm weather, with concerns falling along with temperatures.