I don’t think that he just thinks about that, he must be obsessing a lot if he has
OCD. This tendency is based on unnatural
fear and will eventually lead to OCD, if it hasn’t already. There must have been some childhood experience around fear that has not been resolved and it is coming up now in this form. He must meet with a counselor along with his parents and find out where this fear originated and what the occasion was. The obsession is about hygiene and perhaps
infection that stimulates this kind of reaction. He will need to get a reality
check with a medical person to
dispel these fears and
accept that his immune system is able to fight minor infections rather efficiently. Of course he must be able to trust that source and accept it as a fact: this may take time but is a very important exercise in his therapy. He may also learn that certain amount of hygiene is essential but not extreme and any excessive forms are to be considered as OCD. They will finally cripple him if it reaches chronic states of OCD. If it has already reached difficult proportions, you may need to go on medication and the counselor will advise you so.
