2004-1-26
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VOICE ONE:
This is SCIENCE IN THE NEWS, in VOA Special English. I'm Sarah
Long.
VOICE TWO:
And I'm Bob Doughty. In February, the World Health Organization
will hold a series of meetings in Geneva, Switzerland. Health
experts and representatives of drug makers will discuss the newest
developments in the continual fight against influenza.
VOICE ONE:
The flu -- in humans and birds --
is our subject this week.
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VOICE ONE:
Influenza is a common infection of the nose and throat, and
sometimes the lungs. It is caused by a virus which passes from one
person to another.
The flu causes muscle pain, sudden high body temperature,
breathing problems and weakness. It is most common in the winter
months.
Generally, people feel better after a week or two. But the flu
can kill. It is especially dangerous to the very young, the very old
and those with a weak defense system against disease.
VOICE TWO:
Historical records have described sicknesses believed to be
influenza for more than two-thousand years. The Roman historian Livy
described such a disease attacking the Roman army. People in
fifteenth century Italy thought the sickness was caused by the
influence of the stars. So they named it "influenza."
In seventeen-eighty-one, influenza went from Europe to North
America to the West Indies and Latin America. It spread in Asia in
eighteen-twenty-nine, then again in eighteen-thirty-six. It also
traveled to Indonesia, Russia and the United States.
In eighteen-eighty-nine, the flu began in Central Asia, spread
north into Russia, east to China and west to Europe. Later, it
affected people in North America and Africa. Experts say
two-hundred-fifty-thousand people died in Europe in that flu
pandemic. Worldwide, the number was at least one-million.
VOICE ONE:
But the deadliest outbreak of influenza on record involved a flu
that first appeared in Spain. The so-called Spanish flu killed
between twenty-million and fifty-million people around the world in
nineteen-eighteen and nineteen-nineteen. Even young, healthy people
became sick and died in just a few days.
Times when diseases spread throughout the world are called
pandemics. The W-H-O says the next flu pandemic is likely to kill as
many as six-hundred-fifty-thousand people in industrial countries.
But it says the greatest effect will likely be in developing
countries. The agency notes that health care resources in those
countries are limited, and populations are weakened by poor health
and diet.
Researchers say the new kind of flu will appear unexpectedly.
They will not have enough time to identify it and produce a vaccine.
That is why they are developing faster ways to produce vaccines.
Eighty years ago, the flu virus took months to spread around the
world. Today, airplane travel means a virus can spread around the
world within days. Experts say another virus like the one that
appeared in nineteen-eighteen could be as dangerous as any disease
ever known.
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VOICE TWO:
Medical experts have identified three major kinds of flu. They
call them type A, B and C. Type C is the least serious. People may
get it and not even know it. But researchers study the other two
kinds very closely. Viruses change to survive. This can make it
difficult for the body to recognize and fight an infection.
A person who has suffered one kind of flu usually cannot develop
that same kind again. The defense system produces antibodies. These
substances stay in the blood and destroy the virus if it appears
again. But the body may not recognize a flu virus that has even a
small change.
VOICE ONE:
There are some antiviral drugs that doctors may use to treat
influenza. But health officials say the best thing is to get a
yearly vaccine to prevent the flu.
Each year, medical researchers work to develop vaccines to
prevent the flu from infecting people. They meet in February to
discuss which kinds of flu viruses to include in the next
formulation. They try to decide which vaccines will be most useful
in fighting against the kinds of flu they think will appear months
later.
For this flu season, the vaccine chosen a year ago did not
include the virus known as the Fujian strain. It came from Fujian
province in China. It appeared late. To avoid a delay, it was not
included in the vaccine.
VOICE TWO:
No one knows yet exactly how much protection the vaccine provided
people this flu season. The northern flu season usually does not
begin until December. This season, however, people started to get
the flu in October. The World Health Organization says the majority
of cases identified so far have involved the Fujian strain.
As of last week, the W-H-O reported that influenza remained
widespread in many countries in central and eastern Europe. Cases
also increased in Italy and Japan. And the flu remained widespread
in some parts of Canada and the United States.
((MUSIC BRIDGE))
VOICE ONE:
Humans are not alone. Chickens and some other animals also get
the flu. Since December, parts of Asia have had high levels of bird
flu. Avian influenza virus has jumped to some people. But direct
contact with chickens or their waste has been suspected. The World
Health Organization says there has been no evidence that the virus
has spread person-to-person.
Researchers are concerned about what could happen if the virus
mixes genetic material with human flu virus. The new virus might
then spread from person to person. People would become infected with
proteins their bodies have never seen before. So they would have no
defense.
VOICE TWO:
Scientists are especially concerned about Asia, where many human
influenza viruses first appear.
In nineteen-ninety-seven, an outbreak of bird flu in Hong Kong
infected eighteen people and killed six. Workers killed more than
one-million chickens to control the threat.
Last year in Hong Kong, bird flu infected two people and killed
one. Also last year, a different flu virus infected some
agricultural workers and killed one person in the Netherlands.
In the current outbreak, the W-H-O says Vietnam and South Korea
have the first epidemics ever documented in those countries. Japan
has its first epidemic since nineteen-twenty-five.
VOICE ONE:
But Vietnam and Thailand had the only human cases confirmed as of
Monday. At least seven people in Vietnam have developed bird flu.
Six of them died. Of those, five were children. In Thailand a
six-year-old boy became the first death in that country. Thailand is
the fourth largest exporter of chicken in the world.
Announcements of flu outbreaks in chickens expanded in recent
days to also include Indonesia and Cambodia. Pakistan and Taiwan
have both reported outbreaks of less serious forms.
Health officials say chicken and eggs that have been well cooked
should be safe to eat. The W-H-O says poultry should be cooked to
seventy degrees Celsius. And the agency advise people to wash their
hands after touching poultry products.
VOICE TWO:
Millions of chickens have died of bird flu, or been killed in an
effort to contain the spread. The World Health Organization says it
is also working to develop a vaccine to protect people from the bird
virus.
The agency, part of the United Nations, says the effort requires
the use of a new technology. This is called "reverse genetics."
Scientists collect the virus from human victims. Then they mix
genetic information from that virus with a virus grown in a
laboratory.
The resulting virus is recognized by the defense system in the
body and causes a protective reaction. Drug companies could then use
this virus to produce large amounts of vaccine. But the W-H-O says a
vaccine may not be ready for several months to several years.
VOICE ONE:
The World Health Organization says influenza is thought to result
in two-hundred-fifty-thousand to five-hundred-thousand deaths a
year. As many as five-million people get severe cases of the flu.
Lost productivity adds up to great economic costs. So medical and
agricultural officials say stopping the spread of influenza is one
of their most important jobs year after year.
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VOICE TWO:
SCIENCE IN THE NEWS was written by Nancy Steinbach. Caty Weaver
was our producer. This is Bob Doughty.
VOICE ONE:
And this is Sarah Long. Join us again next week for more news
about science in Special English on the Voice of America.