Copepods associated with a perirectal abscess and copepod pseudo-outbreaks in stools for ova and parasite examinations.

We observed copepods, an intermediate host for several human parasites, in material obtained from a perirectal abscess of a 22-year-old man with Crohn's disease. We subsequently noted copepod "outbreaks" in stool specimens submitted for ova and parasite examination. Copepods in the hospital tap water supply were the source for one "outbreak".