Article: The Evolution of the 1918 Flu Epidemic

Discussion in 'Health and medical' started by Robert Karl Sto, Feb 6, 2004.

  1. 1918 killer flu secrets revealed

    Scientists have worked out how the virus which caused the world's worst ever flu epidemic infected
    man. They believe the virus, which claimed the lives of 50m people around the world, jumped from
    birds to humans.

    The breakthrough, published in Science, should help doctors identify which future bird viruses pose
    a threat to man at an earlier stage.

    But the National Institute for Medical Research team warns viruses cannot be stopped from crossing
    between species.

    They also say their work is unlikely to aid the current fight against avian flu in the Far East as
    knowing the structure of a virus is not enough to block its progress.

    The key first stage of infection is for the flu virus to attach itself to the cells in which it
    will breed.

    It does this by using spike-like molecules called Hemagglutinins (HA) that bind to particular
    receptors on the surface of cells in the body.

    Human and bird virus HAs interact with different cell receptors and therefore bird viruses do not
    usually infect humans.

    However, the NIMR team has studied the HA of the 1918 virus in close detail, and found that only
    minor changes in its structure were required for it to start to bind with human cells as well as
    bird cells.

    This gave it the ability to pass from birds to humans, and then between humans - with
    devastating results.

    Read the rest at BBC News

    Comment: From "The Greatest Benefit to Mankind: A Medical History of Humanity from Antiquity to the
    Present" by Roy Porter, p.18 of the Hard Cover Edition, we read:- "The agricultural revolution
    ensured human domination of planet earth: the wilderness was made fertile, the forests became
    fields, wild beasts were tamed or kept at bay; but pressure on resources presaged the disequilibrium
    between production and reproduction that provoked later Malthusian crises, as well as leading to
    ecological deterioration. As hunters and gatherers became shepherds and farmers, the seeds of
    disease were sown. Prolific pathogens once exclusive to animals were transferred to swineherds and
    goatherds, ploughmen and horsemen, initiating the ceaseless evolutionary adaptations which have led
    to a current situation in which humans share no fewer than sixty-five micro-organic diseases with
    dogs (supposedly man's best friend), and only slightly fewer with cattle, sheep, goats, pigs, horses
    and poultry.

    Many of the worst human diseases were created by proximity to animals. Cattle provided the pathogen
    pool with tuberculosis and viral poxes like smallpox. Pigs and ducks gave humans their influenzas,
    while horses brought rhinoviruses and hence the common cold. Measles, which still kills a million
    children a year, is the result of rinderpest (canine distemper) jumping between dogs or cattle and
    humans. Moreover, cats, dogs, ducks, hens, mice, rats and reptiles carry bacteria like Salmonella,
    leading to often fatal human infections; water polluted with animal faeces also spreads polio,
    cholera, typhoid, viral hepatitis, whooping cough and diphtheria."

    Settlement helped diseases to settle in, attracting disease-spreading insects, while worms took up
    residence within the human body. Parasitologists and palaeopathologists have shown how the parasitic
    round-worm Ascaris, a nematode growing to over a foot long, evolved in humans, probably from pig
    ascarids, producing diarrhoea and malnutrition. Other helminths or wormlike fellow-travellers became
    common in the human gut, including the Enterobius (pinworm or threadworm), the yards-long hookworm,
    and the filarial worms which cause elephantiasis and African river blindness. Diseases also
    established themselves where agriculture depended upon irrigation - in Mesopotamia, Egypt, India and
    around the Yellow (Huang) River in China. Paddyfields harbour parasites able to penetrate the skin
    and enter the bloodstream of barefoot workers, including the forked-tailed blood fluke Schistosoma
    which utilizes aquatic snails as a host and causes bilharz ia or schistoso-miasis (graphically known
    as 'big belly'), provoking mental and physical deterioration through the chronic irritation caused
    by the worm. Investigation of Egyptian mummies has revealed calcified eggs in liver and kidney
    tissues, proving the presence of schistosomiasis in ancient Egypt. (Mummies tell us much more about
    the diseases from which Egyptians suffered; these included gallstones, bladder and kidney stones,
    mastoid-itis and numerous eye diseases, and many skeletons show evidence of rheumatoid arthritis.)
    In short, permanent settlement afforded golden opportunities for insects, vermin and parasites,
    while food stored in granaries became infested with insects, bacteria, fungoid toxins and rodent
    excrement. The scales of health tipped unfavourably, with infections worsening and human vitality

    Moreover, though agriculture enabled more mouths to be fed, it meant undue reliance on starchy
    cereal monocultures like maize, high in calories but low in proteins, vitamins and minerals; reduced
    nutritional levels allowed deficiency diseases like pellagra, marasmus, kwashi-orkor and scurvy to
    make their entry onto the human stage. Stunted people are more vulnerable to infections, and it is a
    striking comment on 'progress' that neolithic skeletons are typically some inches shorter than their
    palaeolithic precursors.

    * Smallpox, the largest of all viruses, is the product of a long evolutionary adaptation of cowpox
    to humans - something clearly perceived two hundred years ago by Edward Jenner. His An Inquiry
    into the Causes and Effects ... of the Cow Pox (1798) noted that:

    The deviation of man from the state in which he was originally placed by nature seems to have proved
    to him a prolific source of diseases. From the love of splendour, from the indulgence of luxury, and
    from his fondness for amusement he has familiarized himself with a great number of animals, which
    may not originally have been intended for his associates.

    Jenner thus perceived the dangers animals posed to human health. Now, in the late 1990s, the
    transmission chain between the cattle disease, bovine spongiform encephalopathy (BSE), and the human
    Creutzfeldt-Jakob Disease (CJD), is a hot epidemiological and political issue in Europe.

    Posted by Robert Karl Stonjek.

  2. Peter F.

    Peter F. Guest

    "Robert Karl Stonjek" <[email protected]> wrote in message
    news:[email protected]...
    > 1918 killer flu secrets revealed

    Just as on a down-to-earth personal note:

    I missed out on any chance of having met my grandfather's oldest sister because of that
    flu epidemic.

    [If that flu epidemic is not "natural selection pressures" in action - and by me somewhat more
    vividly personally illustrated - for ya, then nothing is! %-\ ]