What I will say is that my youngest came home with it from kindergarten. All three of my kids ended up with it. I still never did. BUT it was the most harrowing month of my life. It sucks! I don't wish it on anybody!!!! My girls both have long hair. It was hours of treatments and picking nits. It was lots of wasted money on treatments that didn't work and hours in laundromats, because it is easier to wash and dry EVERYTHING at once instead of a load at a time at home. After lots of $$$$ and several hours of my life I was finally told about a natural treatment that works and that was the end of our lice ordeal.
The way I see it now. . .the risk may not be huge, but after everything I had to go through to get rid of them. . .NO WAY am I taking the slightest risk. . .especially if it's known. I wouldn't be driving anyone I actually knew who had lice or was recently exposed and likely to get it, like a sibling.
It's hell! Really. That's just how I feel.