Sunday, May 03, 2009

The swine flu virus



Health officials across the world fear this could be the leading edge of a global pandemic emerging from Mexico, where seven people are confirmed dead as a result of the new virus.
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On Monday April 27th, the World Health Organization (WHO) raised its pandemic alert level to four and then five on its six-level threat scale, which means they've determined that the virus is capable of human-to-human transmission.
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The initial outbreaks across the planet reveal an infection already traveling at higher velocity than did the last official pandemic strain, the 1968 Hong Kong flu.
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The number of fatalities, and suspected and confirmed cases across the world change depending on the source, so your best bet -- if you want the latest numbers -- is to use Google Maps' Swine Flu Tracker.
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Several nations have imposed travel bans, or made plans to quarantine air travelers that present symptoms of the swine flu, such as:
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Fever of more than 100
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Coughing
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Runny nose and/or sore throat
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Joint aches
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Severe headache
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Vomiting and/or diarrhea
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Lethargy
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Lack of appetite
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Top global flu experts are trying to predict how dangerous the new swine flu strain will be, as it became clear that they had little information about Mexico's outbreak.
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It is as yet unclear how many cases occurred in the month or so before the outbreak was detected.
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It's also unknown whether the virus was mutating to be more lethal, or less.
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One thing is clear though most people have likely been alarmed by the media's coverage of the swine flu scare.
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It is very difficult to forecast a pandemic, and a rash response can be extremely damaging.
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To put things into perspective, malaria kills 3,000 people every day,and it's considered "a health problem"
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But of course, there are no vaccines for malaria that can take in billions of dollars in a short amount of time.
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So what is the swine flu?
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Regular swine flu is a contagious respiratory disease, caused by a type-A influenza virus that affects pigs.
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The current strain, A(H1N1), is a new variation of an H1N1 virus -- which causes seasonal flu outbreaks in humans -- that also contains genetic material of bird and pig versions of the flu.
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Interestingly enough, this version has never before been seen in either human or animals
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All H1N1 flu's are descendants of the 1918 pandemic strain and have mutated many times since then
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This is the reason why flu shots may or may not work in any given year because of these mutations.
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Therefore, there's no vaccine available for this current hybrid flu strain, and naturally,this is feeding the fear that millions of people will die before a vaccine can be made.
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However, there is one very important fact here.
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Just a couple of months ago, scientists concluded that the 1918 flu pandemic that killed between 50-100 million people worldwide in a matter of 18 months -- which all these current worst case scenarios are built upon -- was not due to the flu itself!
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Instead, they discovered the real culprit was strep infections.
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People with influenza often get what is known as a "super infection"with a bacterial agent.
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In 1918 it appears to have been streptococcus pneumoniae.
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Since strep is much easier to treat than the flu using modern medicine, a new pandemic would likely be much less dire than it was in the early 20th century, the researchers concluded.
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Others, such as evolutionary biologist Paul Ewald, claim that a pandemic of this sort simply cannot happen, because in order for it to occur, the world has to change.
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Not the virus itself, but the world.
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In a previous interview for Esquire magazine, in which he discusses the possibility of a bird flu pandemic, he states:
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They think that if a virus mutates, it's an evolutionary event.
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Well, the virus is mutating because that is what viruses and other pathogens do.
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But evolution is not just random mutation.
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It is random mutation coupled with natural selection; it is a battle for competitive advantage among different strains generated by random mutation.
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For bird flu to evolve into a human pandemic, the strain that finds a home in humanity has to be a strain that is both highly virulent and highly transmissible.
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Deadliness has to translate somehow into popularity;
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H5N1 has to find a way to kill or immobilize its human hosts, and still find other hosts to infect.
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Usually that doesn't happen
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Ewald goes on to explain that evolution in general is all about trade-offs, and in the evolution of infections the trade-off is between virulence and transmissibility.
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What this means is that in order for a "bird flu" or "swine flu" to turn into a human pandemic, it has to find an environment that favors both deadly virulence and ease of transmission.
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People living in squalor on the Western Front at the end of World War I generated such an environment, from which the epidemic of 1918 could arise.
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Likewise, crowded chicken farms, slaughter houses, and jam-packed markets of eastern Asia provide another such environment, and that environment gave rise to the bird flu -- a pathogen that both kills and spreads, in birds, but not in humans.
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We know that H5N1 is well adapted to birds.
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We also know that it has a hard time becoming a virus that can move from person to person.
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It has a hard time without our doing anything.
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But we can make it harder.
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We can make sure it has no human population in which to evolve transmissibility.
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There is no need to rely on the mass extermination of chickens or swine
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There is no need to stockpile vaccines for everyone.
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By vaccinating just the people most at risk -- the people who work with chickens, swine and the care givers -- we can prevent it from becoming transmissible among humans.
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Then it doesn't matter what it does in chickens or swine
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Remember also that, despite the fantastic headlines and projections of millions of deaths, the H5N1 bird flu virus killed a mere 257people worldwide since late 2003.
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As unfortunate as those deaths are,257 deaths worldwide from any disease, over the course of five years, simply does not constitute an emergency worthy of much attention, let alone fear!
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Your risk of being killed by a lightning strike in the last five years was about 2,300 percent higher than your risk of contracting and dying from the bird flu.
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In just one year (2004), more than 1,170 people died from lighting strikes,worldwide
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So please, as the numbers of confirmed swine flu cases are released,keep a level head and don't let fear run away with your brains.
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And if you need a good worry then yes we are overdue a pandemic however this swine flu does not look like it

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