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NEWS RELEASE · 8th July 2010
BC Centre for Disease Control
Vacation season is underway and the BC Centre for Disease Control (BCCDC) is reminding British Columbians to protect themselves from West Nile Virus (WNV) this summer. WNV is transmitted from birds to people through the bite of an infected mosquito.

"In past years, other provinces in Canada and neighbouring states in the U.S. have had outbreaks of WNV," said Dr. Bonnie Henry, physician epidemiologist with the BCCDC, an agency of the Provincial Health Services Authority. "Two British Columbians were infected in the province last year and, as we don't know what 2010 will bring, it's always prudent to be prepared. In fact, central Washington State, about 200 kilometres south of our province, has already had positive mosquito samples."

This year, B.C. has had a cool spring. However, as it becomes hot, the risk increases of WNV showing up in the province.

"While WNV won't occur in all areas of the province, regions such as the southern Interior and Fraser Valley are at higher risk. This is because the virus was present in low levels in these areas last year, and because they generally experience higher summer temperatures than other parts of B.C.," said deputy provincial health officer Dr. Eric Young. "If any positive WNV activity is detected, public health officials will be alerting residents of the affected region."

Eighty per cent of people who are bitten by a mosquito and infected with WNV will not have any symptoms. About 20 per cent of infected people may develop some symptoms, including fever, fatigue, headaches and swollen lymph glands. In rare cases (one in 150), WNV can cause severe illness, such as inflammation in or around the brain (encephalitis or meningitis) or polio-like paralysis, that can occasionally result in death.

There are many things British Columbians should do to reduce their risk of being bitten by mosquitoes that may carry WNV, including:

* Remove any standing water outdoors from empty containers (e.g. flower pots, wheelbarrows, old tires, barrels, tin cans and even bottle tops) at least twice a week.
* Drill holes in used containers so water can't collect.
* Change water in bird baths twice weekly.
* Immediately remove water that collects on swimming pool covers, and ensure that the pool's pump is circulating.
* Clear leaves and twigs from eaves and storm gutters throughout the summer into early fall so water doesn't pool or collect.
* Check flat roofs frequently for standing water - you can apply environmentally safe mosquito larvicides available at garden centres to standing water that cannot be drained.
* Ensure that drains and drainage ditches are not clogged.
* Stop mosquitoes from entering your home or other premises (this includes checking windows and door screens for holes or tears, and making sure they fit snugly into their frames).
* Take personal protective measures outdoors such as wearing long sleeves and pants, weather permitting, with light colours and a tight weave, as well as a hat - especially at dawn and dusk when mosquitoes that can carry WNV are most active.
* Use federally registered mosquito repellents such as those containing DEET and PMD (also known as lemon eucalyptus oil), strictly according to directions. Re-apply repellents as often as necessary.

Just as in previous years, the BCCDC is asking the public to be on the alert for dead birds from the corvid family such as crows, magpies, ravens or jays, as these are very sensitive to WNV and could serve as an early warning that the virus has entered an area.

To report dead corvids, for the very latest on the WNV situation in B.C., and for relevant information on the disease itself, visit

The BCCDC has also developed a supplementary education package for teachers who are looking to supplement their Science and Technology 11 Health module (PLO: Science and Tech 11 Science module-Health-D1). The WNV Education Package can be downloaded from