Avian influenza viruses (of which there are 15 Types) infect wild bird populations, particularly water birds, typically with out causing symptoms. The virus spreads through bird faeces and contaminated water or dust, When avian influenza spreads to poultry or other birds, it can cause more severe disease. Outbreaks of avian influenza have been recognized in poultry flocks in most countries of the world for many years.

There are several types of avian influenza. the strains that cause the greatest number of deaths are called highly pathogenic avian influenza (H5N1). This virus was found to cause disease in people exposed to infected birds. Fortunately, the virus was not able to spread from person to person.

The strain of H5N1 that was has now emerged in many Asian countries. Millions of poultry have been slaughtered. A number of human cases and deaths have been confirmed in people who had close contact with chickens, with no evidence of effective human-to-human spread of infection. The Diseases Control Section - Public Health Directorate is closely monitoring the avian influenza situation.