My brother has pinworms?

He has had them for quite awhile, and does nothing to get rid of them. Neither does my mom. He isn't very hygienic. By that I mean, after he takes care of his business he doesn't wipe nor does he wash his hands. He doesn't wash his body everyday, and if he does it's once a day. The last time he brushed his teeth was 2 years ago. Please help me, I want to know what to do. If I dont go around him at all he will get mad, because he knows the reason. However I don't want to get these. I'm actually the COMPLETE opposite of him. I find his lifestyle nasty and disgusting. I don't see how anyone can live like he does.