MSNBC 12/14/03: Experts predict global flu pandemic, coming from rural Asia

[Guest guest]

" New strains of the flu virus, and so potential pandemics,

get their start in rural Asia, where the various strains that infect

chickens and other birds, pigs and humans can mingle. That gives them

a chance to swap genetic information as well as mutate on their own. "

 

 

http://msnbc.msn.com/id/3684599/

Experts predict worldwide flu outbreak

Global pandemic likely, health authorities say

 

The Associated Press

Updated: 4:30 p.m. ET Dec. 14, 2003

 

NEW YORK - As bad as this year's flu season is, it hasn't

brought the worldwide outbreak known as a pandemic. But experts warn

that a pandemic is coming, it's just a question of when.

" It's going to happen, " said Dr. Greg Poland of the Mayo

Clinic. " For the American public in particular, I think it will be

horrific. "

Many Americans haven't experienced the overwhelming crush of

patients at hospitals and doctors' offices and the widespread fear a

flu pandemic could bring. And by historical pattern, Poland said it's

about time for the next one.

There have been three in the past 100 years, igniting in 1918, 1957

and 1968. There's no way to predict when the next one will appear,

but the pattern does give experts pause.

It's all up to a virus that is variable and fickle, constantly

changing its genetic makeup, and the time when it hits upon a

combination that lets it take off worldwide is a " roll of the genetic

dice, " said Dr. William Schaffner of Vanderbilt University.

So the lack of a pandemic in the past 35 years basically

means " the genetic dice haven't been rolled that way, " Schaffner

said. " While we're grateful for that, it makes us nervous. "

There's plenty to be nervous about. It's estimated that in

the industrialized nations alone, the next pandemic is likely to send

1 million to 2.3 million people to the hospital and kill 280,000 to

650,000, according to the World Health Organization. Its impact will

probably be greatest in developing countries.

As a practical matter, flu shots probably could not be

counted on to prevent a pandemic. For one thing, pandemic virus

strains emerge unexpectedly, and there would probably not be enough

time to recognize the threat and then provide vaccines that target

them, Schaffner said. What's more, many countries outside the United

States wouldn't have the means to give enough flu shots to stop the

spread, Poland said.

Dr. Robert Couch of the Baylor College of Medicine noted that

health authorities are making major efforts to prepare for

controlling a pandemic, including putting an emphasis on developing

and manufacturing vaccines faster and in greater quantities.

The pandemic of 1918-19, known as the Spanish flu, sickened

an estimated 20 percent to 40 percent of the worldwide population,

with a death toll believed to exceed 20 million. In the United States

alone, some 500,000 people died. An ordinary flu epidemic kills an

average of 36,000 Americans.

The next pandemic, the Asian flu of 1957-58, killed about 70,000 in

the United States, while the 1968-69 Hong Kong flu led to about

34,000 deaths in the United States. Scientists suggest several

reasons why this rate was lower than in previous pandemics, including

that the illness did not gain momentum until near the school holidays

in December, when children were home rather than infecting each other

at school.

 

Flu viruses start in rural Asia

New strains of the flu virus, and so potential pandemics, get

their start in rural Asia, where the various strains that infect

chickens and other birds, pigs and humans can mingle. That gives them

a chance to swap genetic information as well as mutate on their own.

The potential spark for a pandemic occurs when that

environment produces a new virus that infects people and bears

surface proteins that people's bodies have never seen before. That

means people have no natural defense against it.

In contrast, ordinary outbreaks like this year's come from a

virus that has changed only slightly from previous ones, so that the

population it enters still has some natural immunity from encounters

with the previous germs.

But the genetic shift alone is not enough to launch a

pandemic. In addition, the new virus must acquire the ability to pass

easily from person to person, either by random genetic change or by

picking up genetic material from a previous human flu virus.

The world has had some close calls in the past few years,

says Richard Webby of St. Jude's Children's Research Hospital in

Memphis. In 1997, a bird flu in Hong Kong jumped to people, killing

six. But the virus never developed the ability to pass easily from

person to person, Webby said. Hong Kong authorities slaughtered 1.4

million chickens to end the threat.

Just this year, authorities became alarmed when a father and

son in Hong Kong were hospitalized because of a bird flu virus, and

when flu virus infected some workers in the Netherlands who had

slaughtered infected chickens. The Netherlands outbreak was contained

by anti-flu drugs and fast vaccination, and slaughter of the poultry,

Webby said.

 

What do you know about the flu?

Scientists have been noticing a lot of flu virus in chickens

and pigs globally, and a lot of variety in the strains, which is

worrisome, Webby said. It's impractical to develop vaccines against

all the animal strains in case they jump to humans, and there's no

reliable way to identify the most hazardous ones, he said.

When the next pandemic shows up, experts say, it will find a

population with many more vulnerable people like the elderly, infirm

and those with weakened natural defenses than were living 35 years

ago. It will also find a trimmed-down hospital system with fewer beds

to handle a surge of patients. And while today's anti-flu drugs will

probably attack the new strain, that's not yet clear. Supplies of the

drugs and vaccines would be strained.

But still, with the improvements in health care since the

last pandemic, might the next one be less serious?

" I want to believe that, " Poland said, " but we won't know

until it happens. "

 

Copyright 2003 The Associated Press. All rights reserved. This

material may not be published, broadcast, rewritten or redistributed.

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