washington state is one of the pesticide-resistant head lice hotspots and has been for a long time so my entire family, all my friends, and everyone i knew from age 6-50 just went through a lice reinfection cycle like ten times over the course of about three years in the late 90s-early 2000s and none of the Known Facts about louse infestation had any bearing whatsoever on how it went down.
OTC treatments didnt work, the lice were very obviously transferring between people through casual, non-scalp-temperature contact and on surfaces, between people who were not sharing beds, hats, hair implements, etc. my best guess is they're not studying wild-type lice in labs and are using isolated lab strains to test shit, and of course the "you didnt follow treatment instructions" excuse is universal, but not sending a child home for at least several days to deal with combing and washing clothing is insane to me. that's how you get permanent classroom lice.
the OTC pesticides just don't work anymore for most infestations in the USA, they're reliant entirely on physically combing through a fussy child's entire scalp and hair length with what amounts to a flea comb, which hurts, particularly if the kid has any hair texture whatsoever. i have no idea how a parent is supposed to drop everything and treat an infested household (it's everyone, if one person in the house has it, everyone has it or will have it) in their 2 free hours between 3pm and 7am the next morning, but every time an infected child goes back to that classroom they will get more lice and leave more lice, like one of those penny jars at checkout.
this continued for us until i heard something about mayonnaise, decided that sounded gross but that the principle (physically smothering the lice to death while making the hair easier to comb) seemed fine, and gave everyone the vaseline treatment, which also prevented any additional lice from starting a life cycle over or hopping on and surviving, because it created a totally hostile environment for several weeks until the vaseline shampooed out.
they can survive 24 hours off a human host, thats plenty of time to fall onto a desk, chair, hat, or hairbrush and then transfer to someone else.
