I had never really heard about them until I had kids myself. Thinking back as a child I can remember several times being in pain with an itchy bum, along with my siblings, and parents shouting at us because it must be us not wiping properly blah blah blah we were dirty that's why our bums were sore. Looking back it was probably thread worms.
I'm in my mid 40's and have grandparents in their 90's and 100's. You'd think it was a common thing that was known about? Or maybe not, my Mums family background were a bit nuts.
My boys have never had nits, well never anything for us to notice, we used to check everytime the nit letters got sent home from school. It's not anything we did to prevent it, they just never had itchy heads. We've had quite a few attacks of threadworms tho.
The first time it happened we didn't know what it was until we were all complaining very badly. After some googling (google was just about a thing then) we had a look that night at my eldest Oh god!!! I still remember the wriggling and stinging. We washed everything, again and again, got tablets and were very careful for a while. It all cleared up.
From then we had quite a few episodes of night itchyness but we sprung into action as soon as he got upset. It always seemed to happen when school started, or we went away. I wonder if he reacted particuarly badly to them because we could almost use him as a timetable or canary. Every start of term, one week later he would start to scratch. The day he started to whine was the time family emergency measures were put in place. We ended up taking worming pills on holiday just in case, well that was after a campsite in France one year.
I don't know if he reacted badly to them so was more likely to scratch, therefore more likely to have them under his finger nails, and that never ends well. They're always in us and around us but infestations are usually pretty self limiting. My other son never seemed to react in the same way.
What we found helped was a good layer of vaseline around the area and telling them it's ok to scratch but do it through pants. We havn't had a problem for years since they left the first years of primary.