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Why are the health experts concerned about avian flu?
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H5N1
The current strain of bird flu infecting poultry flocks in Asia-H5N1-is highly
contagious among birds and has resulted in the death or destruction of over 150
million birds. The outbreaks are the most widespread and severe on record.
Infected birds often die within two days. As of early 2006 birds in at
least 30 countries have been affected.
Because such viruses rarely infect people, however, scientists fear we may have
little or no immunity to them, making us particularly susceptible to illness should
H5N1 undergo the mutations necessary to spread among humans.5
High mortality rate in humans
Since 2003, there have been nearly 200 documented cases of human infection with
H5N15 among people working in close contact with infected domesticated birds in
Asia, Europe and other parts of the world.3,5
According to the World Health Organization, in the first 194 cases of bird-to-human
transmission of H5N1, there were 109 deaths.6 In other words, more than half of
those infected have died. This mortality rate of roughly 56% is one reason public
health authorities worldwide are so concerned.
Person-to-person spread unconfirmed5
Thus far, it seems difficult for humans to acquire the virus from birds and even
more difficult for the virus to spread among people. In fact, no suspected cases of
person-to-person transmission have been confirmed thus far. This indicates that the
species barrier is still fairly strong.
However, given how devastating H5N1 has been both for birds and the small number
of humans it has infected, health experts are concerned that further mutations of
H5N1 could change the virus into a form easily transmitted from person-to-person,
resulting in a worldwide outbreak of the disease, or "pandemic."
Learn more about pandemics, including the likelihood that one will occur, and
what the impact would be on America.
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Tell-A-Colleague
