My OCD is based on hypochondria. I am constantly worrying about my health. I don't fear contamination like a lot of people with OCD. I don't feel the need to obsessively wash my hands 50 thousand times and whatnot. I do, however, fear contamination of germs from a sick person, and contracting whatever they had. I'm afraid of becoming contaminated by undercooked meat (e-coli), raw eggs (salmonella), or picking up my turtles (also salmonella).
Probably not the fear of contamination like you mentioned, but I thought mine was a little similar.