And honestly I am very pro-science but the “do no harm” bias in medicine makes me fundamentally question a lot of the recommendations. If it was just slightly better to deworm, do you think they’d recommend it? And then face accusations after any side effects (even if it was statistically the right call to do).
It's really not that - people have a fundamental desire to take action to mitigate tail risk even when that action poses more actual risk. You have to look at risk-reward tradeoff across the population. Treating the entire population for a disease very few of them have will almost certainly yield more (and potentially more harmful) realized side-effects than the actual primary effects being caused by the disease itself. Especially when patients aren't seeking treatment, so are most likely asymptomatic.
Ditto testing low-risk populations for all sorts of conditions they mostly don't have. Even a test that is 99% accurate in a high-incidence population is going to be utterly ineffective when applied to the general population. Bayes theorem tells us this. The side effects up to and including death of investigating or treating these false positives adds up to a real net-negative situation.
If it was even an eency weency bit better to treat in the US I would say they would overwhelmingly do so because they'd be sued into the ground otherwise.
tl;dr: especially when it comes to treatments, action is not always better than inaction. Generally, the US medical system tends towards action.
I read that sentence a few times. 99% accurate seems quite high. WSJ recently opined about the 1-in-5 cancer misdiagnosis rate.
https://www.wsj.com/articles/are-you-sure-you-have-cancer-di...
"Are You Sure You Have Cancer?"
It's a bit easier to understand if you think of the extreme case: if the disease is completely eliminated than all positives are false-positives.
Second, absent actual testing, the risk/reward of deworming is very much a function of the likelihood that you actually have one or more of these worms. That probability is too low in, say, the US to give routing deworming positive expected value. It’s telling that even routine testing isn’t worth the time/cost.
Thirdly, it’s not like… _exactly_ clear that all of these parasites are a problem in the first place. Many of them are frequently asymptomatic with negligible long term consequences. There are even those who believe that the near eradication of hookworm and its minor gut immunosuppressive effect in the developed world is the explanation for much higher rates of inflammatory bowel disease. I that one, but the general idea is that a lot of these worms just don’t actually cause much harm.
And lastly, deworming medications aren’t exactly a joke. They can have serious risks associated with them. Overall it just doesn’t make any sense to routinely deworm in the developed world.
IDK whether this is significant to the original question (de-worm or not) because I'm not qualified to speculate, but I think it certainly suggests that at least for some cities, the evidence should be re-evaluated with realistic sanitation conditions in mind.