Risk of West Nile Virus increasing due to warm weather

The BC Centre for disease control is warning that an increase in the number of mosquitos, also increases risk for West Nile Virus.

Higher temperatures mean more mosquitoes, and the BC Centre for Disease Control is warning that some of them may carry West Nile Virus.

Increasing numbers of mosquitoes have been particularly noticeable in the Okanagan and the Fraser Valley, and people in those regions and elsewhere should take appropriate precautions to prevent mosquito bites.

West Nile Virus (WNV) is transmitted from birds to people through the bite of an infected mosquito. So far this year there have been no positive test results in B.C. from human, animal, or mosquito samples. However, there have been reports of positive samples in Washington, Oregon, Manitoba and Ontario.

About 20 per cent of people who are bitten by a mosquito and infected with WNV may develop some symptoms, including fever, fatigue, headaches and swollen lymph glands. In rare cases (one in 150), the virus 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.

To reduce the risk of being bitten by mosquitoes:

  • If possible, avoid being out from dusk to dawn as mosquitoes that carry WNV tend to be active at these times.
  • Wear protective clothing, especially outside in the early evening and at dawn. This includes long-sleeve shirts or jackets and long pants that mosquitoes cannot bite through. Tuck your pants into socks for extra protection.
  • Avoid dark-coloured clothing as it can attract mosquitoes.
  • Use mosquito netting for babies and toddlers in cribs and strollers.
  • Use mosquito repellent. Putting on personal insect repellents that are federally registered, such as those that contain DEET (N,N-Dethyl-m-toluamide) or PMD (lemon-eucalyptus oil) is an effective way to protect yourself from mosquito bites.
  • There are also many repellents that have been shown NOT to protect against mosquito bites, including bug zappers, devices that give off sound waves and Citrosa plants.

The public can help monitor for West Nile Virus by reporting dead corvid birds (crows, ravens, magpies and jays) by using the form at westnile.bccdc.org.

BCCDC, an agency of the Provincial Health Services Authority, provides provincial and national leadership in public health through surveillance, detection, treatment, prevention and consultation services. The centre provides both direct diagnostic and treatment services for people with diseases of public health importance and analytical and policy support to all levels of government and health authorities.