This is the End
This post is from regular guest blogger:
Ed Rybicki, Department of Molecular and Cell Biology, University of Cape Town, South Africa.
This is the End. Or the beginning of the end. Or possibly, the end of the beginning?
To misquote the immortal Bill Shankly: “It’s not a matter of life and death: it’s much more important than that”.
Having hopefully alarmed you, let me explain: a group of mainly Thai researchers has, in the latest Journal of Virology, just published a paper entitled “An Avian Influenza H5N1 Virus That Binds to a Human-Type Receptor“. They say, nice and succinctly in their abstract, that “We describe here substitutions at position 129 and 134 identified in a virus isolated from a fatal human case that could change the receptor-binding preference of HA of H5N1 virus“.
And this is a big deal, why?
Well, wild birds are the natural reservoir of just about the entire genetic repertoire of influenza viruses – and particularly of Influenza A viruses, the nastiest ones that get into humans. In fact, humans have been infected to our sure knowledge with viruses which have only 3 of 9 neuraminidase (N) and 5 of 15 or more haemagglutinin (H) gene combinations – and human pandemics in the last 100 years have only been caused by H1N1 (twice), H2N2 and H3N2 viruses. Of course, other viruses have been picked up in humans, but usually as a result of direct human-animal or human-bird contact: these include cases of H7N7, H7N3, H9N2 and H10N3 infection, which pop up, and then disappear.
And then, of course, everyone’s favourite candidate for the next Big One: H5N1 highly pathogenic avian influenza. Far from being a transient phenomenon, this has established itself as an endemic virus in chickens and other domestic fowl in Indonesia, Vietnam, Thailand and possibly Egypt, and keeps popping up in western Europe, mainly in migratory waterfowl. It has also infected over 320 people worldwide – and killed more than 190 of them, which is what makes it so sinister a threat.
One of the reasons that we are not constantly overrun with avian flu viruses popping straight out of birds and into people, and why we haven’t yet had a human H5N1 pandemic, is that bird-infecting flu virus H proteins bind to a sialic acid (SA) α2,3Gal(actose) receptor – which in birds is predominantly found in the enteric tract, which is why the virus is shed prolifically via faeces in birds, but is not much found in humans except for deep in the respiratory tract, which is difficult to reach. Thus, while humans can be infected by H5N1 viruses, this is rare, and so far onward transmission to other humans has not been reliably documented. Human-adapted flu viruses, on the other hand, bind preferentially to an SAα2,6Gal receptor – which is found predominantly in the upper respiratory tract, meaning the virus can much more easily infect and be transmitted. The frightening thing is that it takes only a few mutations in the H gene – 3 in the case of the legendary H1N1 Spanish Flu pandemic virus – to change from one type to the other, and only 2 to bind both types relatively weakly.
So Prasert Auewarakul and colleagues have isolated, from a fatal infection of a 5-year-old boy, a population of H5 HA sequences which are distributed evenly between the bird type (SAα2,3Gal-binding) and a mutant type (SAα2,3Gal- and SAα2,6Gal-binding). The mutant HA protein had two substitutions, at positions 129 and 134 (lL129V and A134V). These two residues are located close to part of the receptor binding domain, and apparently alter the binding specificity by changing the configuration of the binding pocket.
The implications of this are very worrying indeed: a lethal virus which can bind both bird and human receptors was selected for in a single bird-human transmission event – just like the Spanish Flu H1N1 HA reconstructed from archival tissue samples, which we should need no reminding, went on to kill in excess of 60 million people. In the age of the steam train and ship…. This means that we could be just one infection away from The Big One – with death tolls predicted to be in the range of tens of millions.
…of our elaborate plans, the end
Of everything that stands, the end…
Thanks to Jim Morrison and The Doors
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Related:
- Influenza: H5N1 Updates
- UK preparedness for pandemic influenza
- The Biology of Influenza
- Influenza pandemic – when?
We are facing the last days of our life.We’ll be ended sooner.We have been cursed by so many kinds of diseases.The outbreak of them we can withstand for.
Another *manmade* viral event for population control.
Man-made?
Creepy. How the timing on this?
Two hours ago I started reading a new online novel called ED Day. It’s about what happens to the survivors of a bird flu pandemic that kills millions in Sydney, Australia.
It only started publishing in the last couple of days. Someone know something we don’t?
BTW – link for bird flu pandemic novel is here :
http://www.ed-day.blogspot.com
it’s weird but straightforward. Done like a journal or a diary it appears. First chapter is about how they clear away the dead from the streets and watch the suburbs burning up.
There’s some stuff about purposeful depopulation too.
Like I said – weird timing.
[...] Update: More news on the bird flue problem – This Is The End [...]
Could you tell us where we can find this information please?
Hey why don’t you tell them about they much scarier form of Influenza? The one WHO is keeping quiet about but that kills 250,000 to 500,000 people EVERY YEAR.
Well, OK, WHO aren’t keeping quiet about it as such, they just don’t talk about it because even though “Bird Flu” has only killed 195 people in 5 years, “Bird Flu is gonna kill us all!” is a much more effective fund raising measure than “Normal every day human flu is gonna kill 250,000 to 500,000 of us, and there is nothing we can really do about it, but maybe you could give us a bit more money so we can tell you that human flu is gonna kill between 250,000 and 500,000 of us every year?”
Here is the WHO fact sheet:
” In annual influenza epidemics 5-15% of the population are affected with upper respiratory tract infections. Hospitalization and deaths mainly occur in high-risk groups (elderly, chronically ill). Although difficult to assess, these annual epidemics are thought to result in between three and five million cases of severe illness and between 250 000 and 500 000 deaths every year around the world. Most deaths currently associated with influenza in industrialized countries occur among the elderly over 65 years of age.
Much less is known about the impact of influenza in the developing world. However, influenza outbreaks in the tropics where viral transmission normally continues year-round tend to have high attack and case-fatality rates. For example, during an influenza outbreak in Madagascar in 2002, more than 27 000 cases were reported within three months and 800 deaths occurred despite rapid intervention. An investigation of this outbreak, coordinated by the World Health Organization (WHO), found that there were severe health consequences in poorly nourished populations with limited access to adequate health care (see “Outbreak of influenza, Madagascar, July-August 2002,” Weekly Epidemiological Record). It is not possible to extrapolate the exact annual burden of influenza in the tropics from data from such occasional and severe outbreaks.”
http://www.who.int/mediacentre/factsheets/fs211/en/index.html
Notice that? Normal human Influenza killed three and half times as many people in ONE SINGLE OUTBREAK that lasted a little over 3 months in 2002, as “Bird Flu” has killed since then.
Do you remember seeing the breathless news articles warning about that epidemic that was part of a wider pandemic? Neither do I.
The difference is no vaccine for H5N1 if it becomes pandemically viable.
>>>The difference is no vaccine for H5N1 if it becomes pandemically viable.<<<<
vaccines for virus? viral diseases?
don’t feed the b.s. by big pharma – virus is mutating all the time. how can you stop it from mutating? vaccines are hopeless.
Hey, some interesting comments here…!
I liked Karmakaze’s especially, as it fits right in with the flu lecture I have been giving in various forums recently. I note that ORDINARY flu kills more people in the US alone every year the TOTAL of all Marburg and Ebola outbreaks that have ever been recorded (>40 000). So, yes: ordinary flu (H3N2 and H1N1) is as big a problem in terms of deaths/yr as measles (>500 000 deaths).
And, getting down to Dr No’s comments – these are PREVENTABLE deaths, in that we HAVE effective flu vaccines. It’s just that that there are >6 x 10exp9 people in the world, and a maximum world production capacity of ~450 x 10exp6 doses. And the vaccines do work, well. They cope with the mutation by releasing a new vaccine from scratch every year – something that is a VERY good model for the HIV problem, incidentally.
And yes, Marc Devereux, this is a manmade (or human-made) problem: without the vast domestic fowl industry (formal and backyard) the H5N1 HPAI avian flu would never have become endemic in as many places as it has. But sorry, MB: like HIV was NOT an American-made virus aimed at Africans, H5N1 is NOT an Israeli-made virus aimed at Asians. That’s a conspiracy theory way too rich for rational people! Nature is way better than we are at engineering outbreak viruses; we are just really good at creating the conditions necessary for unikely events to occur. Things like monoculture, encouraging breakouts of plants viruses. Artificially high densities of one kind of animal (bees, cows, sheep) – or even of people.
Pandemics are just Nature’s way of saying “thin out, people”….
your credibility is in question now.
i work with one of the top 50 microbilogists in the world.
the information you received IS accurate.
go find out.
Its pretty ridiculous to reduce a mere plague to a special event by Nature.
Plagues are so common it would be the unusual generation that did not experience one in a generation.
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