Asia Times: Deadly avian flu on the wing

[unhappycamper]

Deadly avian flu on the wing
By Mike Davis
Aug 18, 2005

The first bar-headed geese have already arrived at their wintering grounds near the Cauvery River in the southern Indian state of Karnataka. Over the next 10 weeks, 100,000 more geese, gulls and cormorants will leave their summer home at Lake Qinghai in western China, headed for India, Bangladesh, Myanmar, and, eventually, Australia.

An unknown number of these beautiful migrating birds will carry H5N1, the avian flu sub-type that has killed 61 people in Southeast Asia and which the World Health Organization (WHO) fears is on the verge of mutating into a pandemic form like that which killed 50 to 100 million people in the fall of 1918.

As the birds arrive in the wetlands of South Asia, they will excrete the virus into the water, where it risks spreading to migrating waterfowl from Europe, as well as to domestic poultry. In the worst-case scenario, this will bring avian flu to the doorstep of the dense slums of Dhaka, Kolkata, Karachi and Mumbai.

The avian flu outbreak at Lake Qinghai was first identified by Chinese wildlife officials at the end of April. Initially it was confined to a small islet in the huge salt lake, where geese suddenly began to act spasmodically, then to collapse and die. By mid-May it had spread through the lake's entire avian population, killing thousands of birds. An ornithologist called it "the biggest and most extensively mortal avian influenza event ever seen in wild birds".

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http://www.atimes.com/atimes/Southeast_Asia/GH18Ae04.html

[necso]

1. There are many naysayers regarding this virus,

some basing their skepticism on past scares. But this one could be different, and it sure looks like it is on the verge of breaking out of any sort of confinement or control (in birds anyway) -- at least given what steps governments (and the "world community", lol) are taking.

And from what I have read, Tamiflu works (best, at least) as a premitigating (and mitigating) agent (not as a "cure"), taken before and during the infection. Moreover, it's possible that even blanket use of the drug in (and around) an infected area (with the necessary population controls, if these are even possible in many places in the world) would not stop the spread. And, of course, there is nothing like enough of the drug. Besides, if there is a serious outbreak somewhere in the world, instead of throwing an adequate (maybe... possibly... hopefully) supply of this drug at the area, the nations of the world will probably hoard it. (In practice, this may amount to considerable hoarding (everywhere) by the elites, their flunkies -- and the otherwise well-connected.)

Moreover, if this virus does as seems likely (breaks out in different variants), then we could essentially be confronting a new flu family (one potentially spread by both birds and humans -- and one humans have no experiential immunity to), with all the attendant problems that this creates for manufacturing vaccines. Of course, there is also the issue of the relevant manufacturing capacity.

And if this breaks out large-scale (and deadly) among humans (which is about when large numbers of people will start taking it seriously -- and, of course, then will there will be hysteria, panic, knee-jerk responses, fear-mongering, etc, etc), the battle is probably already lost.

"Who Wants to Live Forever?", anyway.

[phantom power]

2. some good news and bad news...

The good news is, they have a working vaccine, and they are moving into production. The bad news is, there is no way they will have enough to vaccinate anybody except the "high-risk" groups (elderly, sick, etc) and critical-services (medical people, etc).

The lucky scenario would be that the virus doesn't break out this flu season, and we get another year to make more vaccine (and tamiflu, hopefully). But it's really down to dumb luck. Hopefully, aggressive prophylactic measures can up the odds.

[necso]

3. And that would be a vaccine

for what particular strain(s)?

Or are they making claims that it will work for all (including any new) strains?

[phantom power]

4. Clearly, nobody can make guarantees about future strains. However...

The way the immune system works is by iterative optimization to surface characteristics of whatever it's fighting. So a vaccine based on one strain tends to also be effective against related strains: If your immune system already remembers fighting one strain, it's got a head start against anything similar.

Statistically speaking, of course. Nothing is guaranteed about any of this. We don't know when the virus will evolve into a strain that transmits well between humans, and we don't know how lethal that particular strain will be (my guess is, less lethal than the proto-outbreaks, but that still leaves plenty of room for it being unusually dangerous). There is no way to guarantee the vaccine will be perfectly effective against an evolved strain, but it is most likely to be effective. Certainly far more effective than not having the vaccine.

[necso]

5. Well,

yeah, any vaccine that is close enough to the outbreak strain(s) might (should, even) give the immune system a leg up (which could be very helpful). And it beats having nothing -- although doling out nothing presents somewhat less of a challenge. But, as I understand it, humans are essentially starting off with a blank slate relative to this virus -- and this could make a difference.

And yeah, as I understand it, the way things often work is that some trade-off (effectively) occurs (in practice) between infectiousness and lethality, as in, the strains that have higher infectiousness tend to have lower lethality (dead people are, generally, relatively ineffective hosts, carriers and spreaders -- of many diseases anyway).

But this is not a law, just a trend (and chance has a hand in selection). And there have been any number of instances in history where diseases with high mortality rates caused widespread deaths. Moreover, something that spreads like a flu (with flu-like contagion) really only needs to kill (or disable, which would tend to more localize infection from the individual) some time after becoming infectious in the host. (However, keeping your host moving about and spreading infection for the longest possible time is generally a better "strategy" for spreading the disease, so this can generally be expected to be "selected" for.)

In practice, we might be better off having some low-lethality strain run through the population in order to (hopefully) confer some immunity to other, more deadly strains. And this thing could burn itself out, never really make the break into the human population, or meet some other fate. However, efforts to stop the spread (in birds at least) do not look particularly promising.

But I suppose that making a big deal out of this isn't the best idea... people can probably be expected to react poorly once they get concerned about it -- that is, once the media gets them concerned about it.

[phantom power]

6. I doubt we could ever stop the spread in wild birds.

Now that we've got a vaccine, we might have some hope of stopping the spread into our domestic bird and pig populations. I would hope that some vaccine is spent on immunizing everybody who works with chickens and pigs. That seems to be the highest-probability path into the human population.

The whole situation is an unknown, lurking danger. Anybody who isn't worried about avian flu isn't paying attention.

I'm feeling a bit less worried now that vaccine is in production. For a while, we literally had no defense. Now there's some defense, although it's far from ideal.

I've taken a few basic steps to prepare for an outbreak. I went out and bought some of those hospital face masks, and latex gloves. If it starts spreading, and there isn't enough vaccine, at least my family can reduce the probability of infection. I've also stocked up a bit on emergency food, which might allow us to remain indoors as much as possible.