Wednesday, April 29, 2009

Swine flu, inefficency and am I crazy again?

Ok, so I've been hearing about the swine flu, which naturally the MSM is declaring as a massive emergency that requires huge government action to prevent thousands of deaths etc. Now I'm not going to talk about the implict assumption that such actions is justified by "emergencies" or the responsbility of government for the rapid spread of such pandemics (given the persistent and large-scale subsidy of rapid transportation). Instead I'm going to make a case that government is seeking to maximise that amount of resources spent on these efforts rather than solve the problem.

This case depends on several things being true and if I'm wrong about any of them, please tell me.

The first is that I'm not an Einstein, a Linus Pauling or indeed the intellectual equal of any Noble prizewinner (with the exception of the "Peace" prize, I'll write something about that farce some other time). By this I don't mean I'm subnormal intellectually, merely that my intelligence is not such that it can routinely find implications of facts that nobody else in the world can. If I can see it, chances are other people can too if they want to.

The second is my understanding of the mathematics of epidemics/pandemics. Basically to be an epidemic the average number of people an infected person will in turn effect must be greater than one. If on average each new victim gives the virus to less than one person the total number of victims will be limited to n = a/(1-r) where a is the number of people infected at a particular time and r is the number of new victims each person infects. This is why schools, swimming pools, etc used to be closed, so that on average each person would interact with and have a chance to infect less people. If these measures reduced r below one then an epidemic could be nullifed without any effective treatment for the disease itself. Traditional responses to Ebola outbreaks (developed well before modern medicine) are an extreme example. Sufferers (or suspected suffereres) are simply left in their hut and food pushed in with a long stick. If the person doesn't collect the food for three days a torch is throw onto the thatched roof destroying the virus present in the victim's dead body.

Third is my understanding of what affects the how many people the average victim infects. One of the chief factors is how many people they come into contact with. This varies enormously over the population. Drivers, door-to-door salespeople, shop assistants and airport ticket personnel contact more people than housewives, computer programmers or carers, I will call the former group "high contact" and the latter "low contact" people. Anything that minimises the chances of high-contact people getting the disease is going to be doubly effective at reducing transmission. Firstly the chance of high-contact people getting the disease is higher because they obviously they have more opportunities to catch it. Once infected they similiarly tend to transmit the virus to more people for the same reason. The average number of people a person will infect during an epidemic is therefore increases with the square of his/her number of contacts minus the number of contacts*. If high contact people have a greater tendency to contact other high contact people (for instance if airports have large numbers of high contact people contacting each other) then the situation is worse, increasing with the cube at least of the number of contacts.

If this is true then it's obvious that a small investment in reducing average chance of transmission (either to or from) high contact people will have a large effect on total infections and therefore deaths. Reducing the chance of someone who contacts 10 times more people than the average person is close to 100 times more effective tranmission chances for the average person. What happens if his contacts are only a 10% more likely to be people like him (10 times as high contact) than the contacts of normal people? Well the average number of people infected by the people he infects goes up by close to 1000%, multiplied together this implies over a thousand times more infections from this person than the average person. All of this is an average which includes the possibility that he is never infected.

So clearly these sorts of people, if they exist, are a huge part of the epidemic pandemic problem, yet the targeting of vacinnes is generally towards the elderly, the young and other people who are likely to die if infected. Many of these people are low contact, in fact in the case of the elderly the lack of interaction is often a serious mental and physical health issue in itself. Now of course likelihood of death or serious illness if infected is rightly a factor in determining who should be protected. However isn't it true that the most effective protection of these people is the dramatic reduction in the transmission of the disease?

Now if I'm right about this then it logically follows that, not being a genius, other people could have also figured this out. This is particularly true of those who job is supposedly to prevent or reduce the death toll of epidemics/pandemics. So if they did so and ignored the implications, what other motive is there to do that but to continue wasting resources? The reason they'd want to do that is clear, so they can keep paying the politically influential drug companies and so that the UN's health employees have something to do.

* Because he can't infect the person who originally infected him, therefore the number of people who could infect him is c and the number of people he can infect is c-1.

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