I washed anything washable on high heat with a little bleach and dried on high heat, and vacuumed/bleached everything else as applicable. I also bought a bunch of metal lice combs, marked them with initials, checked every child and every member of my family daily, and sanitized the combs daily. Nothing. Family kept turning up with lice. The lice never spread to anybody else.
Head lice can't survive off their human hosts. They can only live on human hair. Give it a good cleaning and a weekend. For a week or so, keep checking yourself and anybody else in the facility religiously. Very unlikely the lice are coming from you.
People are grossed out by lice so they want to deflect their own thoughts of "Unclean! Unclean! Put them out of the village!" onto you instead of acknowledging that they have parasites.
If you do find them on yourself or a family member, read up on treatment
here. Never, ever do the "plastic bag around the hairline" trick. It's a terrible folk remedy that has
killed at least one child. Better be alive with lice than dead along with the lice.