Tuesday, October 18, 2005

Bird Flu

Well it seems as though this is the new media scare story of the month. New Scientist has a pretty good review of what is going on but even they can't resist speculating on billions of deaths. How scared should we be? A few things to throw around:
  1. These things are deadly, no two ways about it. The 1918 flu alone killed more people than 2 world wars put together.
  2. The flu virus is constantly mutating, there is nothing overly special about this year relative to 20 years ago.
  3. Lately, those mutations have led to a very deadly human flu that luckily doesn't have a human-to-human transmission route.
So my brain asks the question "how many mutations have to happen in a row for a harmless bird flu to turn into a pandemic human flu?". I have no idea and i suspect that most experts have very little either, after all, this question can only be answered with a complete understanding of genetics, proteomics and all sorts of other stuff i've never heard of.
Let's say it happens in two parts; first a deadly-to-humans part and secondly an easy human transmission part. It would seem that half the problem is now done but what are the chances that the next bunch of mutations are going to add transmission and not cripple the deadly aspects? Remember, mutations are random, there is no conscious direction to evolution; the only selection that occurs is whether the random mutation gives rise to a benefit that creates more of that gene - normally by reproduction but in a virus it would mean better infection and production.
So where does that leave us? Almost back at the beginning - A really deadly flu virus that has a small chance of occurring.
Should i worry about it? Personally, i can't see anything that we can do at this point, we are where we are because we didn't do things differently for the last 25 years, hence don't worry, its a waste of time. If it's going to happen, it's going to happen.
All the hype about anti-virals sounds like window dressing to try and make us all feel as though we have some control.
Should we accept this going forward? Now that's an interesting question all on it's own and i think the answer is as bleak as it is simple - Governments focus on problems that are easy to see. Large death counts from remote chances are not things that get a lot of long-term govt funding. We do need to understand what mutations are needed to turn a normal bird flu into a pandemic killer and create a vaccine against all flu virus's (viruses?) and that will be a worthy objective for 25 years but the cynic in me suspects that when this crisis passes, there will be another one, real or imagined, that will seem just as urgent and bird flu will fade into the background.
A last thought to help you sleep at night - even if the chances of rolling a 6 on a die 25 times in a row is 3x10^-20, if you have 3x10^20 people rolling dice, it'll pop up very, very quickly.... evolution is a glacial, constant, and irresistable force of biology, NEVER bet against it over the long term.


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