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)
Clinical DescriptionAn illness caused by the protozoan Giardia lamblia (aka G. intestinalis or G. duodenalis) and characterized by gastrointestinal symptoms such as diarrhea, abdominal cramps, bloating, weight loss, or malabsorption.
Laboratory Criteria For DiagnosisLaboratory-confirmed giardiasis shall be defined as the detection of Giardia organisms, antigen, or DNA in stool, intestinal fluid, tissue samples, biopsy specimens or other biological sample.
ProbableA case that meets the clinical description and that is epidemiologically linked to a confirmed case.
ConfirmedA case that meets the clinical description and the criteria for laboratory confirmation as described above. When available, molecular characterization (e.g., assemblage designation) should be reported.
- CDC. (1997). Case Definitions for Infectious Conditions Under Public Health Surveillance. MMWR, 46(RR-10), 1-55. https://www.cdc.gov/mmwr/preview/mmwrhtml/00047449.htm