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NOTE: A surveillance case definition is a set of uniform criteria used to define a disease for public health surveillance. Surveillance case definitions enable public health officials to classify and count cases consistently across reporting jurisdictions. Surveillance case definitions are not intended to be used by healthcare providers for making a clinical diagnosis or determining how to meet an individual patient’s health needs.

CSTE Position Statement(s)

  • 09-ID-32

Clinical Description

An illness characterized by watery diarrhea, abdominal cramps, loss of appetite, low-grade fever, nausea and vomiting. The disease can be prolonged and life-threatening in severely immunocompromised persons.

Laboratory Criteria For Diagnosis

Laboratory-confirmed cryptosporidiosis shall be defined as the detection of a member of the genus Cryptosporidium by one of the following methods:

  • Organisms in stool, intestinal fluid, or tissue samples or biopsy specimens
  • Antigens in stool or intestinal fluid, OR
  • Nucleic acid by polymerase chain reaction (PCR) in stool, intestinal fluid, or tissue samples or biopsy specimens

Case Classification


A case that meets the clinical description and that is epidemiologically linked to a confirmed case.


A case that meets the clinical description and at least one of the criteria for laboratory-confirmation as described above. When available, species designation and molecular characterization should be reported.


The 2009 case definition appearing on this page was re-published in the 2009 CSTE position statement 09-ID-32. Thus, the 2009 and 2010 versions of the case definition are identical.

Related Case Definition(s)