Intestinal parasites affect mainly developing countries and constitute a public health problem, often related to the lack of efficient health systems, or drinking water sources. These are also enhanced by underlying diseases such as AIDS, which are also present in developed countries. The literature describes that <i>Cryptosporidium </i>spp, <i>Isospora belli </i>and <i>Cyclosporacayetanensis </i>are the parasites most frequently associated with persistent diarrhea in patients with advanced cases of HIV/AIDS. This group of protozoa requires specific tests for diagnosis; the Ziehl-Neelsen stain is one of the nonroutine tests that allows their identification. In most cases, it is not performed in the laboratory if not explicitly requested by the doctor

diarrhea; coccidia; <i>Cryptosporidium</i>; <i>Isospora</i>; <i>Cyclospora</i>; AIDS