Interior Health is reminding residents to take extra precautions against mosquito bites this summer. West Nile virus, a disease that is spread from infected birds to humans through mosquito bites, has been present in B.C. since 2009.
West Nile virus (WNv) was first detected in B.C. in the South Okanagan during the summer of 2009 with the identification of WNv positive mosquitoes and two locally acquired human cases. In 2010, WNv positive crows and one human case were identified further north in Kelowna. Several WNv cases in IH residents also occur most summers due to travel to nearby provinces or states with higher levels of WNv mosquito activity.
“If you have been bitten by a mosquito, you do not have to be tested for WNv,” says Jennifer Jeyes, Communicable Disease Specialist with Interior Health. “Most people who become infected with the virus will have no symptoms or ill effects at all. About 20 per cent of infected people may experience mild to severe flu-like symptoms and less than 1 per cent of people who are bitten by an infected mosquito will get severely ill. The elderly and people with compromised immune systems are generally more at risk of developing a severe illness in response to WNv exposure.”
If you have mild health symptoms that you think might be from the West Nile virus, you should get plenty of rest, drink fluids, and avoid alcohol. If your symptoms persist and seem to be getting more severe, call your doctor.
While the current prevalence of WNv is relatively low in mosquitoes across the IH region, it is important for all residents, regardless of where they live, to take mosquito bite precautions to reduce the chances of infection. The best protection against West Nile virus is to avoid mosquito bites and reduce mosquito breeding areas. Here are some things you can do to protect yourself from West Nile virus:
• Use mosquito repellent – Apply mosquito repellent to areas of exposed skin. Check the product label for instructions on proper use. Repellents containing DEET are safe if the label precautions are followed. DEET-free products are available, but may not provide as long-lasting protection. View the HealthFile on DEET (link below) for guidelines on how frequently you should apply repellant.
• Wear protective clothing – Avoid dark clothing, as it tends to attract mosquitoes. If you are in an area with lots of mosquitoes, wear loose fitting, full-length pants and a long-sleeved shirt to keep mosquitoes from biting. Mosquitoes that can carry WNv are most active at dusk and at dawn. Avoid using floral fragrances such as perfumes, soaps, hair care products and lotions.
• Install mosquito screens on windows – Consider staying indoors between dusk and dawn and in the early evening.
• Prevent mosquito breeding around your home – It doesn’t take much time or water for mosquitoes to develop from eggs into adults. Anything that can hold water can be a mosquito breeding area. Identify and remove potential breeding areas on your property – empty saucers under flowerpots; change water in bird baths twice a week; unclog rain gutters; drain tarps, tires, and other debris where rain water may collect; and install a pump in ornamental ponds or stock them with fish. Stagnant backyard pools can be a big source of mosquitoes and should be maintained regularly to prevent mosquito growth.
B.C. conducts a surveillance program for West Nile virus which includes testing of dead birds in the corvid family: crows, ravens, magpies and jays. These birds are more likely than others to die from West Nile virus. The program also includes trapping and testing of mosquitoes from numerous sites in the province. Members of the public can report or submit dead corvid birds (crows, ravens, magpies and jays) by using the form at http://westnile.bccdc.org or by calling 1-866-300-0520.
Interior Health is continuing to collect mosquitoes for testing through the 2011 season in parts of the region to detect and monitor the spread of the virus. Interior Health traps mosquitoes at 24 sites across the southern Interior and sends them to the provincial lab for testing. They also work with local governments to control mosquito populations and coordinate planning. In the event that a positive mosquito and/or bird are found in an area that previously has not been shown to have West Nile virus, the public will be notified.
