The phobia that results from the fear of dirt is known as Automysophobia. This is an effect where a person gets really uncomfortable when in a dirty place. It is mostly observed when one is uncomfortable with him or herself.
It could be OCD. (obsessive compulsive disorder). That's when you are so obsessed with getting germs you wash your hands constantly, wipe down objects that you touch and it can actually interfere with a normal life. A therapist might help.