Tuesday, January 17, 2006

17 January 2006: Pandemic

Just lost a rather large but well-packed blog due to Internet Explorer crashing (thanks due to the website of the World Health Organisation) and both the clipboard and the 'Recover Post' functionality of Blogger failing me. It was very interesting and all about how bird flu is a threat, but asking why it is a threat right now, and not ten years ago when H5N1 first emerged in Hong Kong. And are the media reporting everything they should? I can't be bothered to re-type it all (I have work to do and a class to teach), but here are some salient points to point you to:
  • The world is afraid of a bird flu pandemic, specifically a soon-to-appear mutation of the H5N1 virus currently rampaging among chickens in Hong Kong and turkeys in Turkey.
  • H5N1 covers quite a range of flu viruses (mainly bird flu) which can be traced back to Scotland in 1959 but which appeared on a large scale in Hong Kong in 1996/97.
  • The name H5N1 refers to the subtypes of surface antigens present on the virus: hemagglutinin type 5 and neuraminidase type 1. (Thanks to the trustworthy Wikipedia.)
  • It was suppressed by mass cull, but re-emerged in the same place in 2002, leading to suggestions of a SARS-style cover-up by the Chinese government about the extent of H5N1 in Guangdong province.
  • It re-emerged as a fast-moving, deadly genotype called 'Z'. This demonstrated almost 100% lethality and led to deaths among humans coming into contact with the birds.
  • There now appear to be two forms of the virus in Vietnam: one which still kills 100% quite quickly, another which demonstrates only 10%-20% lethality, which is good news if you want to live but bad news if you don't want the disease to spread: sick yet living birds are going to have more transmission opportunities than dead birds, and the same would be true among a human pandemic.
  • Passing note: the word 'pandemic' can only be applied to humans. Among animals the correct word is 'panzootic'. Which sounds to me like a third-rate 70's Space Rock band.
  • Both the World Health Organization (no I'm not giving a link after last time, look it up yourself) and Recombinomics (who they?) recognise the established cases of human-to-human transmission.
  • The media like a story when it's not a major election year.

None of which is to say we shouldn't be afraid. The problem seems to be not that H5N1 exists, nor that 'Z' is so amazingly deadly, nor that the bird migratory patterns are currently distributing H5N1 all over the world. The problem seems to be a combination of all the above, along with lesser-reported facts such as the accepted fact of human-to-human transmission of H5N1 (in limited cases) and the emergence of the not-so-lethal strain in north Vietnam. Put it all together, add a healthy dose of fear, a few comments about the cosmopolitan nature of the world, the example of SARS and suddenly you have a good story. The reluctance of the Chinese government to rid Guangdong of H5N1 between 1997 and 2002 certainly didn't help.

History tells us the flu pandemic will come. On the other hand, H5N1 was around ten years ago and it hasn't got us yet. What seems most likely is a non-100% lethal strain will emerge and cause a lot of hassle, but won't kill the millions predicted.

The problem of course remains that, as Patrick Moore so often says, we just don't know.

Postcript: unsurprisingly, Blogger's spellcheck doesn't recognise 'panzootic'. Perhaps more surprisingly, Blogger's spellcheck doesn't recognise 'Blogger'.

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