Influenza A gets around
The influenza A virus isn't fussy. It can infect many species, including humans, birds, sea mammals, pigs, horses and even tigers. Strains of influenza A virus are always present in populations of wild aquatic birds. All this mixing of viruses with different genetic material provides a melting pot for new flu strains.
Every year influenza A viruses cause seasonal epidemics in humans. The very young or the very old are especially vulnerable and can die of the disease.
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| In October 2004 the bird flu virus caused a deadly outbreak in tigers, a species never affected by influenza A before. |
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