Avian Flu History

Avian influenza virus usually refers to influenza Acould spread around the globe in days through
viruses found mainly in birds, but infections can occurmodern jet travel by infected persons.
in humans. The risk is generally low to most people,The current bird flu, a strain known as H5N1, clearly
because the viruses do not usually infect humans.can be transmitted directly from poultry to people.
However, confirmed cases of human infection haveMost cases have been traced directly to contact
been reported since 1997, and the current outbreakwith sick birds, although human-to-human transmission
of bird flu worldwide increases the risk that the virusappears to have occurred in at least one instance.
will mutate into a form which can be spread personH5N1 first appeared in Hong Kong in 1997, and as of
to person.July 26, 2006 there have been 232 cases of flu
All flu viruses are thought to have originated in birds.worldwide, mostly in Southeast Asia, according to the
But scientists also have long believed that in order toWorld Health Organization. Mortality has been greater
cause human epidemics, the viruses first had tothan fifty percent. These figures include only patients
spread from birds to pigs, where genetic changeswhose diagnosis has been confirmed by lab tests.
occur which allow the viruses to spread more easily inCases of severe illness or death are most likely to be
mammals. Flu strains that are more birdlike are morediagnosed and reported, while milder cases go
dangerous to humans because their immune systemsundiagnosed and unreported; therefor it is difficult to
have not been exposed to them before.know the true mortality rate from H5N1.
It is thought that the deadly 1918 flu epidemic, whichDue to the fact that most cases are occurring in
killed 20 to 40 million people, derived from bird flu.third-world countries where health services and
Known as "Spanish Flu" or "La Grippe," the influenzareporting are poor, the actual number is likely much
pandemic of 1918-1919 was a global disaster, and ithigher than the official count. Masato Tashiro, head of
has been cited as the most devastating epidemic invirology at the Tokyo National Institute of Infectious
recorded world history. More people died fromDisease, gave a presentation at a virology
influenza in a single year than in four years of theconference in Marburg, Germany, on November 19,
Black Death or Bubonic Plague from 1347 to 1351.2005 about unofficial bird flu tallies from China. He
Obviously, it is of vital importance that bird flu belisted "several dozen" human outbreaks, nearly 300
contained, and that any infected birds are culled. Itdeaths, 3000 people quarantined, and seven
would only require a handful of mutations in order forhuman-to-human transmissions. The meeting was
H5N1 avian flu to become a pandemic virus like thereported in the German newspaper Frankfurter
one which spread around the world in 1918. OnceAllgemeine Zeitung.
human-to-human transmission evolves, the disease