Cryptosporidium and Isospora species have been recognized as causes of severe diarrhea in immunocompromised hosts, but they can also cause diarrhea in the immunocompetent host.
Oocysts in clinical specimens may be difficult to detect without special staining.
Cyclospora cayetanensis has also been reported to be acid fast. Modified acid-fast stains are recommended for demonstrating these organisms.
