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
http://news.bbc.co.uk/2/hi/health/3455873.stm

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 declining.*

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.
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