Coccidian oocysts during cycling stage outside of host.
These are multi-stage parasites and infect target cells. In this case, intestinal epithelial cells. The varieties of this type of parasite number in the thousands. Toxoplasma is a typical variety which inhabits the common household cat. This species can infect humans and other animals as intermediate and permanant hosts. Diagnosis of this parasite is rare, unless very special tests are conducted.