[ANN]Theories not yet decided

JAKARTA - The American Chamber of Commerce did not have chicken on the menu at a recent luncheon briefing on avian influenza. For the nervous, that was probably just as well.

Although the potentially menacing virus apparently cannot survive at temperatures above 70 deg C, a battery of international microbiologists, epidemiologists and other health experts have made it clear that the virus they call H5N1 is such a mystery they do not really know anything for sure.

At least 65 people have died in Asia since 2003 from a strain of bird flu which, one briefer says, could make a pandemic "as predictable as an earthquake." But there are a lot of things about the disease that no one can explain.

"We`re very suspicious," says Andrew Clements, the senior infectious disease adviser with USAid`s Asian bureau in Washington. "There`s something very interesting going on but we don`t know what it is."

Public presentations are peppered with comments ranging from "we`re watching something in slow motion" and "it is slowly mutating and growing" to the more reassuring "I wouldn`t lose a lot of sleep over it, but be as careful as you can."

Being careful, for the most part, means washing hands regularly - which some experts say can cut chances of catching the disease by up to half - thoroughly cooking poultry meat and eggs as well as staying away from chicken farms.

Indonesia`s first confirmed bird flu deaths - a 37-year-old state auditor named Iwan Siswara Rifei and two of his daughters, aged eight and one - underline the challenges facing the health authorities in trying to find an answer to the gathering crisis.

The family lived in an upscale, gated compound in the western Jakarta suburb of Tangerang with gardens, security guards - and not a chicken in sight. Across the road from their comfortable, tile-roofed home, a neighbor was advertising for sale a BMW sedan in his driveway.

After interviewing and blood-testing more than 300 neighbors, relatives and friends, investigators are still baffled over how the three family members died within nine days of one another, and yet Rifei`s wife and their 12-year-old son were unaffected.

"Everything came up negative and no one else showed any signs or symptoms of the virus," says World Health Organization technical officer Steven Bjorge. "The bottom line is that everything was looked at six times over and nothing made sense. Whatever touched these people has gone now."

Across the street, feces in a bird cage tested positive for the virus - but blood from the pet bird itself was negative. Suspicion initially fell on uncooked eggs, but it was later learnt that they were not part of the year-old baby`s diet.

In fact, there is nothing to indicate that the virus has even entered the food chain - or that it is mutating to the point where it is being passed from human to human, the one all-consuming fear that would preface the beginnings of a pandemic.

Could the family have picked up the virus outside of their tightly knit community? If that was the case, why were they not all infected?

Bjorge freely acknowledges that scientists simply cannot establish - or rule out - whether there was human-to-human contact because they were unable to isolate the initial point of infection.

After all, it took about a fortnight for unsuspecting doctors to determine what the three were suffering from - long enough to hinder a proper investigation.

Adding to the mystery is the fact that the chicken farmers themselves - the segment of the population with the highest exposure - have remained remarkably immune from the disease.

In many of the cases in Vietnam, Thailand and Cambodia, the infection appears to have come from the ubiquitous, scrawny free-range chickens which forage unchecked in lower-income neighborhoods, where they may have picked up the virus from wild bird droppings.

Bjorge is not convinced that migratory birds are at fault, even if there is now evidence that the disease has spread from East Asia to Mongolia and Siberia.

"If that was the case," he points out, "why hasn`t there been anything in Australia? Migratory birds don`t just stop in Asia."

All the same, the WHO office in Jakarta plans to recruit an ornithologist to tell them more about migratory patterns and such community activities as songbird contests and cock fights to get a better handle on what is happening in the wider bird population.

Peter Katona, associate professor of clinical medicine at California`s UCLA Medical Center, points to the avian flu outbreak at northwest China`s Lake Qinghai bird sanctuary, which was first identified by Chinese wildlife officials at the end of April.

Initially, the outbreak was confined to a small islet in the huge salt lake, but within a fortnight it had surged through the lake`s entire avian population, killing thousands of birds. No one had seen anything like it before - or the virulence of the new strain.

Experts say as many as 80 different species of migratory birds use the so-called East Asia flyway between late July and late November, heading south from summer homes like Lake Qinghai to tropical destinations in South and Southeast Asia and eventually Australia.

In the wetlands of South Asia they come in contact with migrating wildfowl from Europe which, like a significant percentage of the duck population, can carry the disease without showing symptoms.

"The bottom line is that avian influenza is endemic and probably ineradicable among poultry in Southeast Asia, and now seems to be spreading at pandemic velocity among migratory birds, with the potential to reach most of the Earth in the next year," says author Mike Davis. His book "Monster At The Door: The Global Threat Of Avian Flu" has just been published.

There have been three flu pandemics in the last century - in 1918-19, 1957 and 1968. The Indonesian health authorities have so far refrained from mass culling and concentrated instead on vaccination as their main strategy.

Katona, who feels the world is "long overdue" for another flu pandemic, doubts this is the right approach. "Once it gets into a flock, it is doomed," he says. "I don`t think there`s a vaccine that can take care of that."

In fact, when H5N1 made its first appearance in poultry last year, it took officials six months to acknowledge it was a looming problem.

Bjorge acknowledges that setting priorities is difficult for a country which simply does not have the resources to deal with a problem of this potential scope.

But with H5N1 detected in the poultry population in western and southern Sumatra, much of Java and small pockets in Kalimantan, South Sulawesi and as far east as West Timor, he says the health authorities need at the very least to strengthen their surveillance system, improve capacity-building and enhance laboratory facilities to prepare for the worst.

Experts agree on one thing: preventive intervention is impossible, even in developed countries. As Kevin Baird, scientific director for the U.S. Navy Medical Research Unit in Jakarta, told his Chamber of Commerce audience recently, "We can`t forecast what a pandemic-capable virus will look like, so we can`t develop a vaccine and know whether it will work or not."

Once a virus is "captured," he adds, the process of developing a vaccine could take six months or more.



By John McBeth The Straits Times, Singapore Asia News Network