Diagnosis
Cryptosporidium oocysts in a
modified acid-fast stain.
(CDC Photo; DPDx)
Diagnosis of cryptosporidiosis is made by examination of stool samples. Because detection of Cryptosporidium can be difficult, patients may be asked to submit several stool samples over several days. Most often, stool specimens are examined microscopically using different techniques (e.g., acid-fast staining, direct fluorescent antibody [DFA] , and/or enzyme immunoassays for detection of Cryptosporidium sp. antigens).
Molecular methods (e.g., polymerase chain reaction – PCR) are increasingly used in reference diagnostic labs, since they can be used to identify Cryptosporidium spp. at the species level. Tests for Cryptosporidium are not routinely done in most laboratories; therefore, health care providers should specifically request testing for this parasite.
Related Diagnostic Links
For more information about laboratory diagnosis of cryptosporidiosis, see the DPDx Web site:
Diagnostic Procedures: Stool Specimens
Page last reviewed: April 16, 2008
Content Source: Division of Parasitic Diseases (DPD)
National Center for Zoonotic, Vector-Borne, and Enteric Diseases (ZVED)