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What is West Nile Virus?

West Nile virus (WNv) is a virus carried by some mosquitoes which have become infected after feeding on birds and/or animals infected with WNv. If you’re bitten by a WNv-carrying mosquito, the virus can then spread to you, putting you at risk for developing West Nile Non-Neurological Syndrome, or the more serious West Nile Neurological Syndrome. Because some mosquitoes carry West Nile virus, it’s best to avoid being bitten at all.

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Am I at risk of WNv infection?

Yes – West Nile virus is a risk to the health of all Albertans, every summer.

Simply, where there are mosquitoes – particularly of the Culex tarsalis family – there is risk of West Nile virus infection.

This is why it is important that all Albertans – including you – take simple precautions to prevent bites, and protect from illness, every day.

Are some people more at risk than others?

West Nile virus is a risk to the health of all Albertans.

Older adults are at greater risk of severe illness, with debilitating lifelong effects; however, all Albertans are at risk of West Nile virus infection. This is why it is important that all Albertans – including you – take simple precautions to prevent bites, and protect yourself from illness, every day.

Am I at higher risk at different times of the year? Or in different places?

Because weather patterns impact the breeding patterns of mosquitoes every year, the level of risk can vary from summer to summer, and from place to place.

None the less, each summer does bring a risk of West Nile virus, and that risk is greatest from early July through to the first full frost of the late summer or early fall season.

Bottom line: whether staying here in Alberta, or travelling, it’s important to protect yourself from West Nile virus infection, every summer.

Do animals or other people put me at risk, or only mosquitoes?

WNv is not known to be spread by birds or other animals to people.

WNv is also not known to be spread from person-to-person, through routine contact.

There is some risk of WNv being spread from person-to-person through blood transfusion and organ transplantation; however, the risk of WNv infection from blood and/or tissues remains very low. Read more on how Canadian Blood Services is protecting the blood supply against WNv. https://web.archive.org/web/20160331220240/http://www.bloodservices.ca/CentreApps/Internet/UW_V502_MainEngine.nsf/page/E_West+Nile+Virus?OpenDocument

It is also possible that a mother infected with WNv can transfer the virus to an unborn baby. This has rarely been associated with a spontaneous abortion or illness to the baby when born. It is important that a baby born to a mother who has had WNv be examined by a doctor.

Is there a WNv vaccine for humans? Can I be immunized against WNv, to reduce my risk?

No – a West Nile virus vaccine for humans has not been developed.

To reduce your risk of illness, you need to protect yourself from mosquito bites.

How does West Nile virus affect animals? Are animals at risk?

Some wildlife – most often birds – carry West Nile virus.

Animals and pets can also be infected by West Nile virus.

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