I presume the lice you had in your family were head
lice. Interestingly, it turns out that
head lice are said not to cause pubic hair infections. The
head lice attach to hairs on the head using a different sort of pinchers than pubic lice and as a result head lice can only attach to head hair and, conversely, pubic lice can only attach to pubic hair.
I hope these comments are helpful. I would suggest you ask a clinician familiar with the problem to take a look.