OCD behavior in eight yr. old?

In the last few weeks my eight year old son has displayed some symptoms of what may appear to be early OCD. Mainly he has had obsessive questions, usually concerns about his or his little sister's health. For example he touched a floor which was a little dirty, my wife told him not to touch the babies mouth, for obvious reasons, he worried for quite a while after the incident that he would die(from touching the floor).
These worries have increased in the last weeks and I don't know how concerned to be. My question is; can OCD be inherited, there is history of in in his family and what should our first line of help be?

[Kevin Kennedy, Ph.D.]

OCD is one of the mental health conditions that does tend to have a strong biological basis and, consequently, an equally strong hereditary link. When there is a family history of OCD, a child is more vulnerable to displaying the condition, though it is not a foregone conclusion that he will. For now, there's no need to be alarmed. Be patient and reassuring with him, but don't overdo it, either. Doing so will only raise the level of anxiety. The best approach is to respond is a calm, casual, reassuring manner.