What happened to bird flu?

[Guest guest]

there were many expert statements last year concerning the pandemic risk.

I remember the list, which you put together about one year ago.

There is not much now.

Is it because the reporters just don't ask anticipating that the readers

are not interested ?

Is it, that the experts just don't release statements to public

and research and prepare more silently ?

Or is it, that they had changed their mind and consider the pandemic

less likely now ?

How do we decipher, what they say about the panflu risk ?

I can't make sense of it.

They were reluctant about giving probability estimates last year,

but this reluctance seems to have increased.

Maybe this degree of reluctance could serve as a pandemic indicator itself...

[Guest guest]

What happened to bird flu? December 15, 2006

Earlier this year, bird flu panic was in full swing: The French feared

for their foie gras, the Swiss locked their chickens indoors and

Americans enlisted prison inmates in Alaska to help spot infected wild

birds.

With the feared H5N1 virus - previously confined to South-East Asia -

striking birds in places as diverse as Germany, Egypt and Nigeria, it

seemed inevitable that a flu pandemic would erupt.

Then the virus went quiet. Except for a steady stream of human cases

from Indonesia, the current bird flu epicentre, the past year's

worries about a catastrophic global flu outbreak largely disappeared

from the radar screen.

What happened?

Part of the explanation may be seasonal. Bird flu tends to be most

active in the colder months, as the virus survives longer at low

temperatures.

" Many of us are holding our breaths to see what happens in the

winter, " Dr Malik Peiris, a microbiology professor at Hong Kong

University, said of the upcoming northern hemisphere winter season.

" H5N1 spread very rapidly last year, " Peiris notes, " so the question

is, was that a one-off incident? "

Some experts suspect poultry vaccination has, paradoxically,

complicated detection. Vaccination reduces the amount of virus

circulating, but low levels of the virus may still be causing

outbreaks - without the obvious signs of dying birds.

" It's now harder to spot what's happening with the flu in animals and

humans, " said Dr Angus Nicoll, influenza director at the European

Centre for Disease Prevention and Control.

While the pandemic hasn't materialised, experts say it's too early to

relax.

" We have a visible risk in front of us, " said Dr Keiji Fukuda,

coordinator of the World Health Organisation's global influenza

program. But although the virus could mutate into a pandemic strain,

Fukuda points out that it might go the other direction instead,

becoming less dangerous for humans.

H5N1 has primarily stalked Asia. This year, however, it crossed the

continental divide, infecting people in Turkey, Iraq, Egypt, Djibouti

and Azerbaijan. But despite the deaths of 154 people, and hundreds of

millions of birds worldwide dying and being slaughtered, the virus

still hasn't learned how to infect humans easily.

Flu viruses constantly evolve, so the mere appearance of mutations

isn't enough to raise alarm. The key is to identify which mutations

are the most worrisome.

" We don't really know how many changes this virus has got to make to

adapt to humans, if it can at all, " said Dr Webby, a bird flu

expert at St Jude Children's Research Hospital in Tennessee.

The most obvious sign that a pandemic may be under way will almost

certainly come from the field: a sudden spike in cases suggesting

human-to-human transmission.

The last pandemic struck in 1968 - when bird flu combined with a human

strain and went on to kill one million people worldwide.

In May, on Sumatra island in Indonesia, a cluster of eight cases was

identified, six of whom died. The World Health Organisation (WHO)

immediately dispatched a team to investigate.

The UN agency was concerned enough by the reports to put

pharmaceuticals company Roche on standby in case its global antiviral

stockpile, promised to WHO for any operation to quash an emerging

H5N1-caused pandemic, needed to be rushed to Indonesia.

Luckily, the Sumatra cluster was confined to a single family. Though

human-to-human transmission occurred - as it has in a handful of other

cases - the virus did not adapt enough to become easily infectious.

This pandemic near-miss highlighted many of the problems that continue

to plague public health officials, namely, patchy surveillance systems

and limited virus information.

Even in China, where H5N1 has circulated the longest, surveillance

isn't ideal. " Monitoring the 14 billion birds in China, especially

when most of them are in backyards, is an enormous challenge, " said Dr

Henk Bekedam, WHO's top official in China.

Of the 21 human cases China has logged so far, 20 were in areas

without reported H5N1 outbreaks in birds. " We need to start looking

harder for where the virus is hiding, " Bekedam said.

To better understand the virus's activity, it would help to have more

virus samples from every H5N1-affected country. But public health

authorities are at the mercy of governments and academics.

Scientists may hoard viruses while waiting for academic papers to be

published first. And developing countries may be wary of sharing virus

samples if the vaccines that might be developed from them might

ultimately be unaffordable.

That leaves public health officials with an incomplete viral picture.

" It shouldn't just be WHO as a lonely voice in the desert, calling for

more viruses (to be shared), " said Dr Jeff Gilbert, a bird flu expert

with the Food and Agriculture Organisation in Vietnam. All countries,

Gilbert said, need to understand that sharing will help them better

prepare for a flu pandemic.

Though scientists are bracing themselves for increased bird flu

activity in the northern hemisphere winter, there are no predictions

about where it might appear next, or whether the much-feared pandemic

will finally be ignited.

" It would be unwise both to have too many expectations about where we

expect to see it, or to be too surprised if we see it appear in new

countries, " said WHO's Fukuda.

Having H5N1 lurking in the environment, says Nicoll of the European

disease control group, is essentially like having an unexploded bomb

in your garden; as the virus spreads even further more people are

around to kick the bomb.

" It may be a live bomb and actually have pandemic potential, " Nicoll

says. " But it might also simply be a dud. "

http://www.smh.com.au/news/health/what-happened-to-bird-flu/2006/12/15/116568586\

2604.html