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by ars 4574 days ago
> may or may not work

That's not accurate. It does work, as in, it does kill bacteria.

The question is if this killing has any value. i.e. does it actually prevent illness. It's pretty clear that in a hospital or nursing home setting triclosan is worth it. It's not so clear if it's worth it in the home.

Then there is a secondary question of does it cause resistance in the bacteria, which then causes it to be less effective where it's needed, i.e. medical settings. For that, it might work, but not be worth it for society as a whole.

3 comments

> > may or may not work

> That's not accurate. It does work, as in, it does kill bacteria.

It's known to work in vitro, and it's known to work in toothpaste.

It sounds like there is no body of evidence to indicate that it works in things like hand soaps. Considering how often agents like this are found to work under one set of circumstances and not under another, I'd say that suggests that whether the agent works for this purpose is still an unknown.

That's the wrong question.

Even if it does work (as in kill bacteria) on the hand, that doesn't mean it works (as in prevents illness).

And in medical settings it's yet another question: does it work (as in prevent the spread of bacteria), even if it doesn't prevent illness.

You have to be careful about what your goal is.

I like the Taleb way to decide on these choices: if you have a very low return on a new medical thing (eg drug) and is supposed to use it often, the very tiny risk inside becomes actually quickly bigger than the benefit. On the opposite, even there is only 70% chance for it to work, go for the new heart surgery technique because if you don't you die anyway. (I am simplifying)

So in result: say no to antibacterial soap, say yes to whatever Doctor House prescribes you.

Bacterial killing is not inherently valuable since so much of your homeostasis is regulated by native bacterial flora, both on the skin and inside the body. It could be that even beyond the skin damage of anti-bacterial soaps, that regularly wiping out your endogenous bacteria could increase certain infectious susceptibilities.

This has been seen with C. difficile infections that occur after broad-spectrum antibiotic administration. These infections are 50% fatal when treated with more antibiotics. Use of fecal transplants, aka the poop of a healthy person put it into the c. difficile patient's stomach, seems to drop that fatality rate to less than 1%. The impact appears to be from the reestablishment of bacterial homeostasis in the gastrointestinal tract.

Study is still ongoing on the broad efficacy of this method, but regardless there is at the very least a substantial subset of the population who are demonstrably at risk from the loss of native flora due to bactericidal treatment.