Avian flu can describe any strain of influenza affecting birds, either wild or domesticated. The fuss over avian flu has only started in 1997 when for the first time it jumped the species barrier, and humans became infected.
Since its discovery in 1959, 15 different subtypes of influenza A virus have been identified in birds. Theoretically more strains could potentially exist, as strains mutate and new combinations of hemagglutinin and neuraminidase protein coat the flu virus. However at the moment the most virilent strain is H5N1 (five parts hemagglutinin, one part neuraminidase proteins). H5N1 is notoriously resiliant to amantadine and rimantadine, two anti-viral medications commonly used for influenza.
Avian flu pathogens can be stored in the intestines of birds, and expelled through their saliva, nasal mucus and droppings, contaminating surfaces and infecting anybody handling them. The symptoms of avian flu include:
In 1997 in Hong Kong eighteen people became infected with the H5N1 strain of avian flu and seven people subsequently died. Authorities noted that the victims all were in close contact with poultry, and that unsanitary markets and other retail outlets contributed to the epidemic. As a preventative measure 1.5 million chickens were culled.
Subsequent outbreaks have been identified:
Avian flu has also been identified in Cambodia, Canada and even in North Korea. The number of deaths in China could possibly be higher than what has been disclosed.
The number of fatalities from avian flu may appear almost trivial compared to other epidemics like malaria and AIDS that kill thousands of people each year. What makes avian flu particularly scary and draws governments into action is the possibility that a new and more lethal strain could evolve that would be easily passed on between people. This could happen if somebody with a common type of flu comes in contact with avian flu, and the two strains meet in the body of the hapless victim and swap genetic material. A pig could also contract these two kinds of influenza, and become a potential pandemic time bomb.