h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

i have just be listening to reports on the telly of yet another death of a 6 year old in Thailand i think they said.

i know nothing of this illness, it's symptoms or how it is contracted. i do know it appears to be getting a foot hold in southern Asia.
the reporters and the Government are talking as if we all know about this deadly virus and as if it has been around for years. yet i know nothing.

if it's so common and has been around for years, why are we only hearing of it now and why is it only just starting to kill humans now? and where has it been before it surfaced in South Korea such a deadly disease and i have never heard of it before and i suspect many others are equally as clueless.

and on a side note, SARS originated from that region of the world not so long ago, is that particular area of the planet a hot spot for Viruses to mutate in? does climate affect virus development and should we expect another super bug scare for this year?

and is there a connection between the two viruses? both have been described as 'Flu' viruses?

It can't be that* deadl, it hardly seems to have killed many people at all... I've only ever heard of it before in reference to it only normally occuring in humans when the immune system is impaired, E.G., immunosuppression, AIDS, and other immunodeficiency states. This seems to be less virylent than SARS, and SARS wasn't that bad...

They (they? well, someone on Radio 4) have been saying that Bird Flu cannot be transmitted from Human to Human, only from Bird to Human, but my fear would be of a mutation that changed that. Is it correct that AIDS developed in Green Monkeys and only became an epidemic when it jumped species into Humans?

SARS wasn't that bad because the powers that be seem to have responded quickly and strigently to contain it. It was pretty bad for the people who died from it. But I realise I may have fallen for some propaganda, and it could just be part of the general panic and paranoia generated by governments that the media thrives on and that helps them all keep us in-our-place...

Er, basicly I've no idea...

I don't think the type folks have quite decided where HIV came from, but yes, one I think favoured idea is that it was a mutated form of the SIV virus that infects monkeys/apes, 'Simian immunodeficiency virus' I think... The whole SARS thing was blown out of proportion, sure, like any illness its pretty bad for those that get it and die, but stuff happens, influenza claims more lives and is more infectous than SARS was/is, and the avian virus appears to have a simularly low mortality incidence, judging by the low amounts of deaths, thus far.... I'm not saying it won't supprize us all and kill the entire human race, just I think it somewhat unlikely... I'm not at all sure about the likelyhood of it mutating to be capible of crossing from human to human,, but I think* I'm correct in saying that because of its low infection rate, it would take some time or be quite unlikely for that to happen... I certainly won't lose any sleep about it, I'm more worried about th eimpending snow in the UK, which is something we are totally unable to cope with, and iwhich, if it comes, will certainly kill a few older membes of the population

cheers 2legs that pretty much puts that to rest. now that just leaves the question of why the media keep writing about such stuff

i love snow we don't get enough of it in southern england

Yes. Why do the media keep harping on about it so much? Indeed this is a puzzle.
There is only one answer, the whole 'media', is in on it.
They know what is really* happening.
Terrorists have unleashed the most deadly virus ever genetically engineered, and have planted infected 'suicide' infected terrorists in every major city in the world, to move, and spread the virus, infecting all peoples they meet, to cast death and distruction across all of the lands.
A giant is stalking us, bearing us off to our graves, and the only thing worse than death will be the knowledge we as a race are distroyed, and the intollerable pain of a long, untreated lingering death, as our ashes blow across teh wasteland of deserted citys, and the rats feed, and the magotts move through our mortal flesh, and Oh, sorry, I've gone 'off on one' a bit : I've no idea seriously, why the media is going so bonkers over it, they did it with SARS, thought they'd have lurnt their lesson.... Perhaps they have decided 'aution' the best option, don't forget, of course, this virus could turn out to be the 'one' that a few months back we thought SARS might be... My brash dismisal of this as a distroyer of nations, is partly due to the hype, and 'disappointment' of SARS, and because, I can't be bothered worrying about contracting a deadly virus that will kill me when I've important matters... such as weather tomatos are vegetables or fruit to consider...

yes, best to watch out for them

what also gets me is the ability of the virus to adapt so it can survive. afterall it is a living organism. but it is completely inept to realise that if it gets too good it will kill all that could host it, thus effectively wiping itself out. not a very good survival trait for any organism. are viruses (and humans) the only beings that will destroy until they cannot be supported themselves

A lot of organisms will do it I think, I seem to remember rats will... No matter how bad and infectious the virus/bacteria is though, there will normally be some individuals that survive because of their genetic make-up; take the individuals lacking the I think its the CC5, or Rantaz receptor, doesn't give them any ill effects lacking it, but it makes them immune to infection with HIV, as the HIV virus uses this receptor on the human cells, as the second thing it needs to bind in order to infect the cells

I condensed the following info from a fact sheet (http://www.who.int/csr/don/2004_01_15/en/) I found on the World Health Orginization website.

It seems to me that Bird Flu is a non-trivial disease, and that the risk that it can mutate into a form that may be transmitted from human to human is quite real. But also note that "WHO does not at present recommend any restrictions on travel to any country currently experiencing outbreaks of H5N1 avian infection in poultry flocks, including countries which have also reported cases in humans."

The third parahraph from the end lists the symptoms.

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Avian influenza is an infectious disease of birds caused by type A strains of the influenza virus. The disease, which was first identified in Italy more than 100 years ago, occurs worldwide.

All birds are thought to be susceptible to infection with avian influenza, though some species are more resistant to infection than others. Infection causes a wide spectrum of symptoms in birds, ranging from mild illness to a highly contagious and rapidly fatal disease resulting in severe epidemics. The latter is known as “highly pathogenic avian influenza”. This form is characterized by sudden onset, severe illness, and rapid death, with a mortality that can approach 100%.

Domestic poultry, including chickens and turkeys, are particularly susceptible to epidemics of rapidly fatal influenza.

All type A influenza viruses, including those that regularly cause seasonal epidemics of influenza in humans, are genetically labile and well adapted to elude host defenses. Influenza viruses lack mechanisms for the “proofreading” and repair of errors that occur during replication. As a result of these uncorrected errors, the genetic composition of the viruses changes as they replicate in humans and animals, and the existing strain is replaced with a new antigenic variant.

The tendency of influenza viruses to undergo frequent and permanent antigenic changes necessitates constant monitoring of the global influenza situation and annual adjustments in the composition of influenza vaccines.

Influenza viruses have a second characteristic of great public health concern: influenza A viruses, including subtypes from different species, can swap or “reassort” genetic materials and merge. This reassortment process, known as antigenic “shift”, results in a novel subtype different from both parent viruses. As populations will have no immunity to the new subtype, and as no existing vaccines can confer protection, antigenic shift has historically resulted in highly lethal pandemics. For this to happen, the novel subtype needs to have genes from human influenza viruses that make it readily transmissible from person to person for a sustainable period.

Conditions favourable for the emergence of antigenic shift have long been thought to involve humans living in close proximity to domestic poultry and pigs. Because pigs are susceptible to infection with both avian and mammalian viruses, including human strains, they can serve as a “mixing vessel” for the scrambling of genetic material from human and avian viruses, resulting in the emergence of a novel subtype. Recent events, however, have identified a second possible mechanism. Evidence is mounting that, for at least some of the 15 avian influenza virus subtypes circulating in bird populations, humans themselves can serve as the “mixing vessel”.

Of the 15 avian influenza virus subtypes, H5N1 is of particular concern for several reasons. H5N1 mutates rapidly and has a documented propensity to acquire genes from viruses infecting other animal species. Its ability to cause severe disease in humans has now been documented on two occasions. In addition, laboratory studies have demonstrated that isolates from this virus have a high pathogenicity and can cause severe disease in humans. Birds that survive infection excrete virus for at least 10 days, orally and in faeces, thus facilitating further spread at live poultry markets and by migratory birds.

The epidemic of highly pathogenic avian influenza caused by H5N1, which began in mid-December 2003 in the Republic of Korea and is now being seen in other Asian countries, is therefore of particular public health concern. H5N1 variants demonstrated a capacity to directly infect humans in 1997, and have done so again in Viet Nam in January 2004. The spread of infection in birds increases the opportunities for direct infection of humans. If more humans become infected over time, the likelihood also increases that humans, if concurrently infected with human and avian influenza strains, could serve as the “mixing vessel” for the emergence of a novel subtype with sufficient human genes to be easily transmitted from person to person. Such an event would mark the start of an influenza pandemic.

Published information about the clinical course of human infection with H5N1 avian influenza is limited to studies of cases in the 1997 Hong Kong outbreak. In that outbreak, patients developed symptoms of fever, sore throat, cough and, in several of the fatal cases, severe respiratory distress secondary to viral pneumonia. Previously healthy adults and children, and some with chronic medical conditions, were affected.

Antiviral drugs, some of which can be used for both treatment and prevention, are clinically effective against influenza A virus strains in otherwise healthy adults and children, but have some limitations. Some of these drugs are also expensive and supplies are limited.

Experience in the production of influenza vaccines is also considerable, particularly as vaccine composition changes each year to match changes in circulating virus due to antigenic drift. However, at least four months would be needed to produce a new vaccine, in significant quantities, capable of conferring protection against a new virus subtype.

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