Flu season in the U.S. is in the middle of its peak, and activity continues to increase, according to the U.S. Centers for Disease Control and Prevention (CDC) in the Situation Update.  Though seasonal influenza causes sufficient concern for public health officials, another issue has surfaced as bird flu claims a life in Canada.

The Vancouver Sun reported that an Alberta resident has died after contracting H5N1 bird flu, the first such case in North America, according to Canada’s health minister.  Though not confirmed by official sources, the victim is reported to be a 20-year-old woman.  While some may be alarmed, public health authorities say that there is no reason to worry.  Health Minister Rona Ambrose says the case was an isolated one and that the risk to the general public is very low. The individual had recently returned from a trip to China.

The government website Flu.gov, which is run by the U.S. Department of Health and Human Services (HHS), states that H5N1 is a highly pathogenic avian (bird) flu virus that has caused serious outbreaks in domestic poultry in parts of Asia and the Middle East. Highly pathogenic refers to the virus’s ability to produce disease. Although H5N1 does not usually infect humans, nearly 600 cases of human cases of H5N1 have been reported from 15 countries since 2003.

The World Health Organization (WHO) reports that there are flu viruses circulating in animals that pose threats to human health.  Humans can become ill when infected with viruses from animal sources, such as avian influenza virus subtypes H5N1 and H9N2 and swine influenza virus subtypes H1N1 and H3N2. The primary risk factor for human infection appears to be direct or indirect exposure to infected live or dead animals or contaminated environments.

Most avian influenza viruses do not cause disease in humans. However, some are zoonotic, which means that they can infect humans and cause disease. The most well known example is the avian influenza subtype H5N1 viruses currently circulating in poultry in parts of Asia and northeast Africa, which have caused human disease and deaths since 1997. As of mid-December, the WHO reports that there have been 648 laboratory-confirmed human cases of H5N1 flu, reported in 15 countries. Of that total, 384 infections have been fatal.

In addition to the bird flu scare based out of Canada, a National Monitor article from earlier this month reported that swine also known as H1N1, is once again a major virus for this year’s flu season.  Unlike avian flu, swine flu is a seasonal influenza and is largely preventable for those that get the seasonal vaccine.