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Patient Education: Diseases Conditions Treatments & Procedures

Avian Flu

Introduction

Wild birds are natural carriers of influenza A viruses and have carried animal influenza viruses, with no apparent harm, for centuries. Migratory waterfowl such as ducks and geese are known to carry viruses of the H5 and H7 strains or subtypes. These viruses are usually in the low pathogenic form or low infection.

The avian or bird flu has been identified as the H5N1 strain of influenza A and has infected many poultry populations and some humans. This strain is highly pathogenic to birds, and has infected a limited number of humans.  There have been over 300 human cases of avian flu reported in parts of south-east Asia and a smaller number of cases reported in the Middle East.

Three to four times each century, for unknown reasons, a radical change takes place in the influenza A virus causing a new strain to emerge.  If this strain is one from the human population is not immune, causes disease in humans, and has the ability to spread easily from person to person, this would create the conditions for an influenza pandemic.

There is currently no pandemic influenza in the world, however, there were three influenza pandemics in the last century.  Many experts believe this strain of influenza A, has a very strong potential to signal the next pandemic influenza or global epidemic of influenza in the next five to ten years.