Giardiasis (Giardia lamblia)

1997 Case Definition

The 1997 case definition appearing on this page was re-published in the 2001 CSTE position statement 2001-ID-08 (available at http://www.cste.org/ps/2001/2001-id-08.htm). Thus, the 1997 and 2001 versions of the case definition are identical.

Clinical description

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)

Case classification

Probable: a clinically compatible case that is epidemiologically linked to a confirmed case

Confirmed: a case that is laboratory confirmed

Print Page | Close Window