New flu pandemic could kill 81 million

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New flu pandemic could kill 81 million

By MARIA CHENG, AP Medical Writer Thu Dec 21, 7:02 PM ET

LONDON - A flu virus as deadly as the one that caused the 1918 Spanish

flu could kill as many as 81 million worldwide if it struck today, a

new study estimates. By applying historical death rates to modern

population data, the researchers calculated a death toll of 51 million

to 81 million, with a median estimate of 62 million.

That's surprisingly high, said lead researcher Murray of Harvard

University. He did the analysis, in part, because he thought prior

claims of 50 million deaths were wildly inflated.

" We expected to end up with a number between 15 and 20 million, "

Murray said. " It turns out we were wrong. "

The new work is published in Saturday's issue of the journal The Lancet.

The 1918 flu outbreak killed at least 40 million people worldwide. But

flu pandemics have varied widely in their severity. The most recent,

in 1957 and 1968, were relatively mild, killing 2 million and 1

million people worldwide respectively.

To get their estimates, Murray and his colleagues examined all

available death registration data from 1914 to 1923. There was

sufficient information from 27 countries, including numbers from 24

U.S. states and nine provinces in India.

The researchers compared death rates during the pandemic to average

death rates before and after. That revealed how much the pandemic flu

contributed to death rates, a figure called excess mortality. They

then applied the excess mortality data to worldwide population data

from 2004.

If their median estimate of 62 million flu deaths occurred in a single

year, the total number of deaths from all causes worldwide would more

than double, jumping by 114 percent.

One surprise in the new study was the huge variation in how different

countries would be affected by a pandemic. The study estimates that 96

percent of the deaths would occur in the developing world. Murray and

colleagues noted there was a 30-fold or more variation in mortality.

" That tells us it's not just the genetic makeup of the virus that will

cause deaths, but that there are a lot of other things that

intervene, " he said.

Determining the mitigating factors might help avert a catastrophe. " If

we can answer that question, we may unlock the mysteries behind which

non-pharmaceutical strategies could significantly decrease mortality, "

said Murray.

Population density, nutrition and immune status could all play roles,

he suggests.

" We know that even if we have much lower numbers of deaths worldwide

than in 1918, the world will be severely stressed, " said Dr. Keiji

Fukuda, coordinator of the

World Health Organization's Global Influenza Program. " Speculating

about the possible numbers is an interesting exercise, but the really

important thing is, what do we do about it? "

Since the pandemic threat rose, with circulation of the H5N1 bird flu

virus on a large scale in late 2003, the global community has

bolstered its pandemic preparedness plans. Medical systems today are

far stronger than they were last century, and the availability of

antivirals and antibiotics — which did not exist in 1918 — should help

greatly. Still, many of these advances remain out of reach for poor

countries.

Another question is the impact a flu pandemic would have on those

infected with

HIV. Seasonal influenza exacts a heavy toll on those with weakened

immune systems. So, in the case of a new pandemic flu, Murray's

estimate might be optimistic.

And while the Spanish flu often has been regarded as a worst-case

scenario, there is no guarantee the next pandemic will not be even

more deadly. Despite the tens of millions of deaths the 1918 flu

caused, the death rate among those infected was approximately 2

percent. The fatality rate for the H5N1 virus is about 60 percent.

However, experts think that if H5N1 were to evolve into a strain

easily transmissible between people, it would also become less deadly.

" It's not in a virus' interest to kill its hosts so readily, otherwise

it can't reproduce, " said Dr. Ian Gust, a flu expert at the University

of Melbourne, Australia.

Still, there is no guarantee that H5N1 would become less deadly.

If it doesn't, " we would be in for a devastating impact, " said Gust.

" All bets would be off. "

http://news./s/ap/20061222/ap_on_he_me/_1

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but they don't take into account the current mortality of H5N1

[Guest guest]

Global flu pandemic could rival death toll of WWII: study

Thu Dec 21, 7:31 PM ET

PARIS (AFP) - A global pandemic of a novel, contagious and lethal form

of influenza could kill as many people in a year as died in World War

II, according to an estimate in a new study.

In an calculation based on mortality from the " Spanish flu " pandemic

that ran from 1918-20, US researchers believe 62 million people could

die in the space of 12 months if a similar pathogen emerged today,

according to a study published in the Lancet.

The vast majority of deaths -- 96 percent -- would occur in the

developing world.

The study, led by Harvard University professor Murray, is

based on death registration data to estimate deaths from the 1918-20

pandemic in 27 countries.

This data was then extrapolated to the worldwide population of 2004.

But it also takes into account gains in prosperity and access to

medical care since 1918, as well as countries' changes in the size and

age of their populations.

Murray's team believe that between 51 and 81 million people could die,

making an average of 62 million, if a similar pandemic were to occur,

on the basis of 2004 data.

Historians variously estimate the death toll from World War II at

between 50 million and 62 million.

The 27 countries included the United States, European nations,

Argentina, India and the Philippines.

The safest place to be would be Denmark, where there would be excess

mortality -- that is, an increase above the normal death rate -- of

0.2 percent over 2004.

At the other end of the scale would be India, where the excess

mortality would be more than 20 times higher, at 4.39 percent.

The study coincides with the scare surrounding H5N1 bird flu, a virus

that is lethal and contagious among birds.

The fear is that this virus could acquire genes that would also make

it easily transmissible among humans, creating as in 1918 and in two

other flu pandemics last century a novel pathogen against which no-one

would have natural immunity.

Murray said the high death toll and its preponderance in developing

countries as compared to rich economies was explained by the different

access to vaccination, antiviral drugs and speedy treatment with

antibiotics to treat secondary infections such as pneumonia.

" The predicted mortality today for India is lower than in 1918 because

there has been significant advances " in Indian prosperity since then,

Murray told AFP.

" The predicted mortality for sub-Saharan Africa, though, is probably

quite similar to what it was in 1918 because there hasn't been that

big a change in per-capita income. "

But, he said, " We saw a strong relationship between mortality and

income in 1918-20, and it was such a strong relationship that there's

nothing to suggest that also won't hold true if something like that

happened again. "

Murray said the findings raised worrying questions about pandemic

preparedness in poor countries, such as early provision of antivirals

that can slow the spread of a pandemic and swift distribution of a

vaccine to deal with the new virus.

" Much of the global policy attention on early detection, surveillance,

national pandemic preparedness plans is going to benefit high-income

and maybe some upper middle-income countries, " he said.

" There really hasn't been, I believe, enough attention on practical

things that low income and lower-middle income countries can do and

that is where most of the harm will come. "

Medical historians disagree over the death toll of the 1918-20

pandemic, which erupted in the trenches of the Western Front in Europe

at the end of World War I.

Estimates vary between 25 and 50 million dead. The upper figure is

more than three times that from 1914-18 conflict itself.