2004-11-23
I'm Bob Doughty with the VOA Special English Health Report.
There has not been a worldwide outbreak of influenza since
nineteen sixty-eight. Experts say there should have been another by
now. They hope to be prepared to limit the effects when the next one
finally happens.
The so-called Spanish flu in nineteen eighteen became the most
deadly influenza pandemic ever recorded. A pandemic is when a
disease spreads around the world. It killed an estimated twenty
million to fifty million people. Almost half were young adults.
There were two other flu pandemics in the twentieth century. The
Asian flu struck in nineteen fifty-seven, and the Hong Kong flu in
nineteen sixty-eight.
Scientists at the United States Centers for Disease Control and
Prevention say the cause of the Spanish flu pandemic is not clear.
But the two others are known to have resulted from a human virus
that became mixed with an avian influenza virus. And that could
happen again.
Scientists first identified avian influenza in Italy more than
one hundred years ago. Bird flu is caused by type A influenza
viruses. Type A are the most common, and usually cause the most
serious flu outbreaks in people.
Currently the most serious kind of bird flu is known as
a-h-five-n-one. It has spread among chickens and ducks in Asia. The
virus has infected at least forty-four people in Thailand and
Vietnam this year. More than thirty of them have died.
Researchers worry that the virus could spread quickly worldwide
if it gains the ability to pass easily between people. Many
researchers say governments must do more to support planning for the
next flu pandemic.
This month, the World Health Organization held a meeting to
discuss efforts to develop a vaccine to prevent infection with the
virus. About fifty experts met in Geneva.
Klaus Stohr heads the global influenza program at the W.H.O. He
says this is the first chance to produce a vaccine that would limit
the damage caused by a flu pandemic. This is the result of
improvements in the way scientists study flu outbreaks in people and
animals.
Scientists are developing two vaccines based on the current bird
flu virus in Asia. To have both of these "candidate vaccines" tested
within a year would cost an estimated thirteen million dollars each.
Medical experts say a vaccine is unlikely to prevent another flu
pandemic, but it could save millions of lives.
This VOA Special English Health Report was written by Cynthia
Kirk. I'm Bob Doughty.