So I tend to go against the grain anyway, but our current obsession with hand washing and the wonders of antibacterial soap – sorry… it is now antimicrobial soap is driving me just a little up the wall.
The climb became faster after suffering from an antibiotic resistant sore throat.
See – the problem here is that we are self selecting for better, stronger, and more infectious bugs. The faster something can reproduce the faster it can respond to environmental factors and boy are we giving them a lot to respond to.
Back when I took Microbiology my lab consisted of taking a petri dish and rubbing my hand on it – taking all of the microorganisms from my hand and giving them a lovely nutritious place to live. After several days I came back to something that looked like this:
From there we then picked one or two colonies – the round spots on the dish – and grew them. Then we had the enviable task of figuring out what they were. We did this by growing them in different petri dishes with different types of food and with antibiotics.
That was really the thing – and the point. Some of the microbes that grew on my hand were susceptible to antibiotics and some were not. And some were in the process of developing immunity – they often had smaller colonies on the antibiotic dish than on the one with just good food.
If I want to get really technical I could tell you all about how antibiotic immunity can be transmitted between bacteria – kind of like sex but not quite – it’s called conjugation. That should worry you because only one bacteria has to develop the immunity and then it can not only create copies of itself (bacteria reproduce by binary fission – one cell divides into two cells). But it can pass the immunity to their friends and family.
Oh, and a bacterial colony can double in size every 10 minutes. They also have a genome with a high base line mutation rate – they can afford to and need to. Individuals are expendable and their environment enormously changeable.
The thing is that all of these things were on my hand so… what happened in the petri dish happens on my hands.
First off – there is a huge difference between washing your hands and washing your hands. We are going to assume, for the sake of this mental experiment, that this hand washing involves one of those antibacterial gels – because they are one of the problems. When you wash your hands with soap and water – you kill everything and then you wash it all off. When you use an antibacterial product it doesn’t get washed off – instead it hangs on providing regions in which resistant colonies can develop.
If I was obsessive about using antibacterial gel hand sanitizer that means that I could be selecting for resistant bacteria and after a single work day (say 10 hours – to make the math easy) I could be washing my hands every 20 minutes – 3x an hour so 30 times in the day. But the stuff I was trying to get rid of was multiplying by 6x an hour so 60 times a day. Each time I used my antibacterial gel I would kill some but not all of the bacteria on my hands. Each time I would be selecting for those bacteria that could live in the new conditions.
Just like I did with my petri dishes.
Now I’m not saying that we are going to develop a ‘superbug’ this way – but it just seems to me to be a bad trend. We know that decades of giving antibiotics to anyone and everyone created some hellish strains of resistant bacteria. Right now infections in hospitals are up – not ones you come in with but the ones you get once you are there. It seems to me such a simple thing to avoid.
No one is saying that you shouldn’t wash your hands – but triclosan hand sanitizers antimicrobial soaps are over kill with some unpleasant side effects. There is indication that triclosan finds its way into human breast milk and has other effects – I haven’t yet tracked down the original articles (the ones published in scientific journals) so if you want to read more see the article below.
So why take the risk… besides you aren’t only using this stuff on your body, it is getting onto other surfaces, into our bodies, and being washed into the water system (that is a post for another time).
But now your thinking H1N1 – well sorry to burst your bubble but H1N1 is a RNA virus that ‘buds’ from the cell taking the components of the cell wall with it. Cell walls are almost entirely made up of a lipid bi-layer – which is not the strongest thing in the world and can destroyed by drying out. H1N1 is being passed by fluid contact – the virus is suspended in droplets – like those you produce when you cough or sneeze and the microscopic ones you create when you talk.
So the odds against being infected by hand to hand contact is astronomical. Besides the best way to destroy a lipid bi-layer is plain old fashioned soap and water.
So the next time you see that hand sanitizer sitting there – give a thought to my petri dishes and all the things we didn’t know about the overuse of antibiotics fifty years ago. Maybe you’ll make a different decision.