CSTE Position Statement(s)
An illness caused by the protozoan Giardia lamblia and characterized by diarrhea, abdominal cramps, bloating, weight loss, or malabsorption. Infected persons may be asymptomatic.
Laboratory Criteria For Diagnosis
- Demonstration of G. lamblia cysts in stool, OR
- Demonstration of G. lamblia trophozoites in stool, duodenal fluid, or small-bowel biopsy, OR
- Demonstration of G. lamblia antigen in stool by a specific immunodiagnostic test (e.g., enzyme-linked immunosorbent assay)
A clinically compatible case that is epidemiologically linked to a confirmed case
A case that is laboratory confirmed
The 1997 case definition appearing on this page was re-published in the 2001 CSTE position statement 2001-ID-08 and the 2009 CSTE position statement 09-ID-34.1 Thus, the 1997, 2002, and 2010 versions of the case definition are identical.
- 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