Friday, 8 May 2009

Herd Immunity

With Swine Flu resonating through the media, the potential for a pandemic is a reminder of the ways in which viruses transmit. Though it's a sad that it takes a threat of this nature to keep people wary of the potential for getting ill. The reaction of medical establishments has been to give simple hygiene advice, hardly befitting a disaster of such magnitude. The Egyptian government slaughtering all the nation's pigs, though completely misguided and unnecessary, is more to the kind of reaction we'd expect. Unlike avian flu, this virus is transmitting human to human and as such any protections need to stop the spread of infection. The standard guidelines for illness are there for a reason, yet should be followed at all times.

It needs to keep being repeated that humans are social creatures, in the context of a society anyone has the potential to be a carrier of a virus. To completely avoid infection from others, it means isolation from society. This option being unfavourable due to the need for society in order to preserve our survival and as such should be a last resort option. So we need to accept that while we are individuals operating within a society, we remain at risk from others and a risk to others. We need to be mindful of what illnesses we could have and how they could spread.

The anti-vaccination people rest almost exclusively on the idea that it is a low risk not to get a vaccine for a now-uncommon ailment. If measles is very rare then the potential risk for not immunising a child is not very high. And if the claims about autism are true (they are not) then it would seem more of a risk to give the vaccine to a child than to not get it. But this individualism brings on the danger that if there were an outbreak, the community would be compromised. This may be individual risk, but there are those who at no fault of their own cannot get the vaccination and are put at risk by those who choose not to. The elderly, infants, and those who are allergic to the injections are all put an increased risk as the more who are not immune greatly increases the potential carriers.

Death of course is not the only problem from getting sick, in the workplace getting sick means lost productivity. And anyone who gets sick has the potential to spread that illness to others and they could suffer the same fate. Last August, I started at a new work environment. 3 days into working there I came down with an illness and had to take a week off to recover, and even then I was still feeling the effects for a while after as my body gradually recovered. But I wasn't the only one, a large portion of the floor were also off sick around that period. Someone came into work ill and in a closed-environment with many people around, the illness took down a lot of people.

Part of the problem in this workplace is that we have a lot of contractors working here. Contractors are paid by the hour, so if they take a sick day then that is 8 hours of lost income. Getting seriously sick could wipe out days of income, a situation nobody wants. Even if one feels up to working, coming into an office environment is inconsiderate as it puts others at risk. Same thing with catching public transport, same thing with participating in communal activities. It should not be a manager's responsibility to make sick people go home, it is an implicit duty of any member of society to be aware of the risks they pose to others. Having a scheme by which the ill are enticed to work and have little reason not to go is just going to cause problems in the long run.

The more infectious a disease, the greater the risk. Say that only 1 in 10 people will become infected by a virus. So if you transmit it to one person, then that person transmits it to someone else, it experiences linear growth. After 10 generations 10 people will be infected. But if it were more infectious and 2 in 10 people will be infected. If you come in contact to the same amount of people, 2 people will be infected and each of those will infect two more people each. After 10 generations, that's 1024 carriers as opposed to 10 if it were twice as infectious. 3 out of 10 and it's 60,000 people after 10 generations. This should demonstrate two things. Firstly that being highly infectious is grounds for social isolation, and secondly that even a few simple measures can significantly decrease the chance of spreading the infection.

To participate in society is to be aware that someone cannot act without regard to others. When it comes to heath, it shouldn't take a pandemic to remind us that one should avoid the sickly and that the sickly should isolate themselves to prevent further spread of that illness. Even taking simple measures such as washing hands properly and covering coughs can be the difference between a small and large outbreak. Waiting until a potential disaster neglects that these measures help save lives and help the community now. It shouldn't take a measles outbreak to get parents to vaccinate their kids, just as it shouldn't take a pandemic to stop people with regular flu from coming to work where they can spread it to others. It's common courtesy!

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