Swine ‘flu and you.

Here’s a little post I wrote for the Young Australian Skeptics; I thought I’d re-post it here.

So-called “swine flu” is, of course, a particular strain of influenza. In this case, the virus is question is a sub-strain of the H1N1 subtype of Influenza virus A, to be specific. There are three distinct types of Influenza virus, type A, type B and type C, and of these, there are distinct subtypes and then individual strains or genetic lines.

“Swine flu” takes this name from the fact that sub-strains of H1N1 influenza are known to be endemic in pig populations. The virus can also infect humans, who acquire it from pigs, especially in the case of people such as farmers who work frequently in close contact with the animals. Occasionally, a porcine strain of flu will mutate in a manner that allows human-to-human transmission of the virus, as with most other influenza infections in humans with which we are all familiar.

Thus, infection with such a sub-strain of the virus is not limited to those persons who have been in contact with infected pigs.

Whilst it is something of a misnomer to call the particular H1N1 strain responsible for recent headlines “swine flu”, since it has thus far not been confirmed in any pigs, the H1N1 subtype is however the most common in pigs, and is known to be associated with previous outbreaks of flu originating from porcine-to-human transmission.

Therefore, this flu strain is at least presumed to have originated in pigs, prior to mutation. This flu strain may be similar to porcine flu strains previously encountered, but it can now really be called, in all honesty, “human flu”, since it is seemingly fully capable of human-to-human transmission and infectivity of humans, just as with any other familiar seasonal strain of flu.

In Thailand, a major exporter of pork, the government chooses to call it “North American” flu. In the Jewish community, however, it has been claimed that calling the disease swine flu is offensive to Jews [4]. Everyone knows that killer flu is totally not kosher. Meanwhile, an Islamic imam has claimed that “swine flu” demonstrates that “scientific truths lie behind the teachings of the Koran that has taken many centuries for man to discover” and that the risk of porcine-to-human viral transmission “shows the truth of our faith” [3].

There is no sure-fire cure for the flu, just like there are no sure-fire “cures” for any viral infection, with the exception of highly effective vaccines for many viral pathogens. However, there are antiviral drugs which are particularly effective against influenza, including against “swine flu”. These anti-influenza drugs include the older M2 inhibitors, amantadine and rimantadine, which are effective solely against Influenza A, and the newer and widely publicized neuraminidase inhibitors, such as oseltamivir (aka. Tamiflu) and zanamivir (aka. Relenza), which seem to be effective against the overwhelming majority of flu infections in humans, including both Influenza viruses A and B.

Because the viral neuraminidase enzyme is such a fundamentally important part of how the influenza virus infection propagates between host cells, it is believed that it will be quite difficult for the virus to develop resistance to these drugs, which is why they are highly prized as effective modern weapons against influenza. However, resistance to amantadine (and its derivatives) has begun to become widespread in flu viruses [1], and over prescription of the drug in humans and the administration of the drug in animal feed to prevent avian influenza [2] are likely contributing factors for this.

Even though the virus is intrinsically less likely to be able to develop resistance to neuraminidase inhibitors, for this reason I feel that it’s important to keep the administration of these drugs in humans to an absolute minimum – in the overwhelming majority of cases, no such drugs are needed. We should certainly avoid the kind of over prescription that we see with antibiotics, even though it’s completely plausible that patients could hassle doctors to prescribe such drugs, simply because they want a quick-fix solution, and these potent and relatively new drugs have been widely publicised in the media.

However, contrary to scare stories in the media, influenza in most cases causes only mild symptoms, and an infected person makes a full recovery without requiring professional medical intervention, such as the use of prescription antiviral drugs, at all. This includes this new H1N1 strain.

To be honest, compared to killer-apocalypse-zombie-flu scare stories in the media, this appears to be a not-particularly-special strain of influenza. Many strains of flu spread easily from person to person via airborne transmission; which is why the little bugger is so familiar to us all. Yes, this strain is seemingly highly contagious, but influenza viruses almost always are. It is not some kind of lethal super-virus that is orders of magnitude worse than anything we’ve ever seen before, although this is the type of thing that sells magazines and newspapers.

Media reporting of the numbers of deaths associated with recent outbreaks of this flu strain, particularly in North America, can be quite deceptive. There have been 172 confirmed cases of the disease in Mexico, we’re told, and 26 deaths.

On the surface, this might seem to indicate that the disease killed more than one in six persons who contracted it, however this is not really the case. Only the most severe cases of such a disease will ever be reported to health authorities, and the overwhelming majority of people will just stay at home for a few days, with some paracetamol, pseudoephedrine and some chicken soup perhaps, and therefore they will never be included in these scary statistics in the media.

Of course, there is no reason to suspect that this particular strain of flu cannot effectively be prevented by vaccination, but the development of new vaccines for the constantly changing seasonal flu strains, as always, takes time. There is, as yet, no vaccine for this particular strain of H1N1 influenza. However, as always, annual influenza vaccination remains the primary means of preventing morbidity and mortality associated with influenza. It’s somewhat plausible that those who are vaccinated against other flu strains may experience some limited degree of protection against this strain.
Vaccines are your friend. Use them. :)

[1]: http://www.cdc.gov/flu/han011406.htm
[2]: http://www.washingtonpost.com/wp-dyn/content/article/2005/06/17/AR2005061701214.html
[3]: http://www.adnkronos.com/AKI/English/Religion/?id=3.0.3257943159
[4]: http://www.google.com/hostednews/ap/article/ALeqM5ieHZRubAS3lyjn2GBiCPkXkHrXwwD97QROAG0

For more information regarding H1N1 “Swine” ‘flu, I suggest you check out the CDC website, this good post over at Depleted Cranium (this one inspired me to write this piece, and I took the figures regarding misleading media reports of mortality from it.)

Also, if in doubt, I suggest you seek advice from a qualified, professional medical practitioner.

I also suggest that if you find charlatan scammers peddling mendacious bullshit as any kind of “treatment” or “vaccine” for any strain of flu, or any other serious medical condition, you report them to your local government healthcare regulatory bodies and/or consumer protection agencies.

Advertisements

About this entry