Mexican swine flu not so scary

After a fair amount of research re flu, sparked by interest in relationship between wild birds and flu, I've been highly impressed by notions stemming from evolutionary biology - which suggest a potent flu pandemic won't happen in absence of social conditions akin to World War One trenches.

Though there is fair amount of panic re current swine flu from Mexico - last night, I walked by hotel where man with Hong Kong's first case was staying, and huge fuss outside, with medics in anti-viral gear, police and media and others in masks; read today of Prof John Oxford suggesting an "Armageddon Virus" is possible - it seems evolutionary biology holding up: deaths mainly in Mexico, and flu that has travelled proving mild (so far!).

Couple of articles suggest this flu isn't real cause for panic.

One article by Wendy Orent - who first informed me re evolutionary biology and flu; includes:

using the lens of Darwinian evolution, certain aspects are starting to come into focus. For one thing, it's clear that the virus, which originated in Mexico, is most virulent in that country. The 1,000 or so reported Mexican cases have been either fatal or severe enough to require hospitalization. But because of natural selection, the strains spreading across the world are milder.

According to evolutionary biologist Paul W. Ewald of the University of Louisville, human influenza is usually a mild to moderate disease because it depends on host mobility to spread. The U.S., Canadian and New Zealand teenagers on their spring breaks did not sit in hospitals with the very sick and dying; they mingled with people who were sneezing and coughing but walking around, riding subways, perhaps going to the beach or dancing in nightclubs. People don't start being really infectious until they show symptoms, and whatever symptoms those people had must have been mild enough to remain out in public. The strains sent out around the world were, by definition and necessity, milder than the most lethal strains.

So why are some of the Mexico strains so lethal? The answer may lie in the virus' possible origin: a giant Veracruz pig farm that raises almost a million pigs a year. According to Devlin Kuyek of GRAIN, an environmental organization, reports have been coming in for months of the appalling conditions in the Perote Valley where the farm is located.

The virus is not a new one, and the strain that's spreading is a milder variety of the original virulent one traced to a Mexican pig farm.

By Peter Palese is the chairman of the department of microbiology at the Mount Sinai School of Medicine in New York, includes:


there is more evidence that a serious pandemic is not imminent. In 1976 there was an outbreak of an H1N1 swine virus in Fort Dix, N.J., which showed human-to-human transmission but did not go on to become a highly virulent strain. This virus was very similar to regular swine influenza viruses and did not show a high affinity for the human host.

Although the swine virus currently circulating in humans is different from the 1976 virus, it is most likely not more virulent than the other seasonal strains we have experienced over the last several years. It lacks an important molecular signature (the protein PB1-F2) which was present in the 1918 virus and in the highly lethal H5N1 chicken viruses. If this virulence marker is necessary for an influenza virus to become highly pathogenic in humans or in chickens -- and some research suggests this is the case -- then the current swine virus, like the 1976 virus, doesn't have what it takes to become a major killer.

Why Swine Flu Isn't So Scary

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Letter I sent the South China Morning Post; published today, in the Sunday Morning Post:
[quote]I used to believe notions that flu could rather magically mutate into a malevolent, super-lethal virus, as suggested by various people, and mentioned by [J.C. Lawrence, in Letters] - and that it would then rampage around the world, killing untold millions.
However, I then saw arguments that this will not happen, based on applying one of the most powerful theories in science - evolution through natural selection - to infectious diseases. In the case of flu, these arguments centre on the need for the disease to be transmitted from one person to another.
Typically, this means transmission from people who are well enough to be mobile - whether walking, riding buses, or taking flights. This in turn means that for a widespread form of human flu to evolve, it must be relatively mild in most people. A disease that greatly sickens and even kills many people will itself quickly die out.
These arguments, from scientists including evolutionary biologist Paul Ewald, explain much that is otherwise puzzling about flu, in both people and birds. The advent of a lethal flu during the First World War is no longer a coincidence, but to Ewald is a direct consequence of the terrible conditions of trench warfare - even very sick people could indeed transmit flu, and the virulent Spanish Flu evolved.
Regular wild bird flus are mild - as birds must fly, even cover vast distances on migration. But cram chickens together in giant poultry farms, and nasty bird flus evolve, including the strains of H5N1 that have caused so much trouble in recent years. The current swine flu is evidently also a product of our farming methods.
Viewing flu as a disease that does not just mutate, but is subject to evolutionary pressures, thus suggests that most of us don't really have much to fear from flu, including swine flu. There's no need to panic. But also, care is surely advisable in using drugs like Tamiflu - in case we push flu evolution towards more resistant forms, leading to there being fewer options for treating infections in people whose medical conditions make them especially vulnerable to flu.[/quote]
 

From the Epoch Times - not mentioning evolution and mobile carriers, but otherwise on the money re overblown fear of swine flu:
[quote]According to World Health Organization’s (WHO) global statistics, 2,185 people have died from the H1N1 virus, while another 209,438 are confirmed to have caught it, as of Aug. 23.
What this also means is that 207,253 people recovered from the virus—a recovery rate of 99.99 percent. Bear in mind that all of these recoveries were before an official vaccine for the H1N1 virus was released. The common, seasonal flu kills between 250,000 and 500,000 people each year, globally, while causing severe illness in between 3 million and 5 million people, according to the WHO.
It is recommended that you read the above paragraph 30 times to deprogram yourself of the media’s over-sensationalized reporting on the H1N1 virus.
...
What the world has seemingly forgotten is that the H1N1 virus is not entirely a new disease. It surfaced back in 1976 and was followed by the same concerns. Back then, the U.S. government launched a mass vaccination campaign, which aimed at inoculating every U.S. citizen. It was soon found that among the many side effects of the vaccine was the deadly Guillain-Barré syndrome.
Ultimately, the H1N1 vaccine of 1976 killed more people than the virus itself, while the fears surrounding the virus never became a reality. More than 40 million people were vaccinated before the vaccine was discontinued. All that was left was a hefty stack of lawsuits from families without mothers and fathers due to the vaccine.[/quote]
What’s Not to Fear About the H1N1 Virus?