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Is Bird Flu (H5N1) still a concern?

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bird flu

A global outbreak of bird flu is still a concern. A pandemic starts when three conditions are met: a new influenza virus subtype emerges; it infects humans, causing serious illness , and it spreads easily and sustainably among humans. Bird flu (the H5N1 virus) amply meets the first two conditions. It’s a new virus for humans and it has infected more than 100 people, killing over half of them. No one will have immunity should an H5N1-like pandemic virus emerge.

Fortunately, the virus has not yet shown efficient, sustained human-to-human transmission. The risk remains that it could acquire this ability as long as chances for human infections occur. These chances will persist as long as the virus circulates in birds, which could endure for years to come. The more human infections occur, the more opportunities the virus has to improve its ability to transmit among humans and develop into a pandemic strain.

Further concerns include: domestic ducks excrete highly pathogenic viruses without showing illness, which complicates control efforts; today’s virus is more lethal when tested on mice and ferrets; it appears to have expanded its host range, infecting and killing mammalian species that were once resistant; and the behavior of the virus in its natural reservoir, wild waterfowl, may be changing.