Birds of a deadly feather

03 November 2005

You pick up on it quickly.

As many alarm bells as scientists and organisations are ringing about the current outbreak of bird flu, just about everyone peppers their sometimes bold statements with plenty of "coulds". Even those who believe that the strain threatening to do the global rounds, H5N1, could [sic] be the one to finally rival the deadly 1918 Spanish Flu.

The villain on that occasion, the H1N1 virus, was also spawned by birds. It cut a swathe across the globe, killing anything between 20 and 50 million people.

Little wonder then that more than a couple of organisations and scientists, even those not given to doomsaying, don't hesitate to herald H5N1 as the rightful heir to the Spanish Flu, trumping the 1957 and 1968 pretenders.

The World Health Organisation (WHO) declared avian influenza "the most serious known health threat the world is facing today". In May, the Royal Institution World Science Assembly (RiSci) teamed up with leading journals Nature and Foreign Affairs to launch the Pandemic Preparedness Project, hoping to light a fire under ill-prepared states.

"Without greater action now, at worst such a pandemic could prove as deadly as any event in the past century, with catastrophic economic consequences," said the RiSci's Professor Susan Greenfield.

Notwithstanding the qualifiers, there are a number of certainties. Scientists are sure, for example, that the virus originated on the farms and teeming markets of Southeast Asia, where humans and poultry are crammed together. They know that it was in that region, also, that domestic flocks infected humans. Chickens and domestic ducks and geese, thought to be the main culprits, then passed it on to migratory ducks and geese.

Once the flu broke out in Cambodia, Thailand and Vietnam, it spread quickly to western China, Siberia, Kazakhstan and Mongolia, even Europe.

At last count, H5N1 had infected 140 million birds and about 120 humans. Around 67 people have died, a worryingly high percentage of those infected.

The sum of all the scientists' fears, of course, is that the virus will mutate to such a degree that, in time, humans will pass it on to each other, in the same way we do the common cold or any other flu.

Much like the 1918 virus is suspected of doing, H5N1 has also jumped the chain of infection, passing directly from birds to humans without, apparently, any of the customary halfway stops at other mammals, typically pigs.

For now.

"We have not the faintest idea what could happen," says Professor Ed Rybicki of UCT's Department of Molecular and Cell Biology, who's been keeping up to date with the virus. "Tomorrow it could recombine in a pig or in a human and produce something that is very infectious."

How to stop the virus in its tracks, then? Everyone - including the Chinese, famous for looking the other way on such occasions - appears to be doing the right things, putting people and areas into quarantine and killing infected birds and poultry by the millions.

It's also been proposed that countries currently free of the disease should consider a ban on imports of domestic poultry and wild birds from affected regions.

There are no guarantees, of course, but those steps could spare countries like South Africa, some distance away from Southeast Asia. An infected goose flying from Asia could be in Europe in a matter of hours. Flight time plus refuellings to South Africa take a good six to seven weeks, and it's unlikely that a sickly bird already stressed out by the migration would survive the trip, says Professor Les Underhill, director of the Avian Demography Unit (ADU) at UCT.

Also counting in South Africa's favour is that the 200 000 or so birds - about 16 species - estimated to migrate here from Asia are from the more far-flung northern areas, away from people and domestic flocks.

A big threat, however, is the smuggling of wild birds.

"That's where the effort needs to be invested," says Underhill.

For now, chicken lovers - for lunch, we mean - can tuck away.

And local bird-watchers need not fret too much, either. To be safe, advises Underhill, just stay away from dead birds, and report any sighting of mass deaths.

Everyone just needs to be alert. That much is certain.

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