Small intestine & ampulla
Infectious disorders
Giardia lamblia
Author: Hanni Gulwani, M.B.B.S.
Topic Completed: 1 August 2012
Minor changes: 17 February 2021
Copyright: 2003-2021, PathologyOutlines.com, Inc.
PubMed Search: Giardia lamblia[TI] small bowel[mh]
Table of Contents
Definition / general | Terminology | Diagrams / tables | Diagnosis | Gross images | Microscopic (histologic) description | Microscopic (histologic) images | Positive stains | Videos | Additional referencesCite this page: Gulwani H. Giardia lamblia. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/smallbowelgiardiasis.html. Accessed May 16th, 2021.
Definition / general
- Protozoan infection associated with malabsorption, chronic diarrhea
- Spreads by fecally contaminated water, common in underdeveloped countries
- Affects 1/3 of homosexual men in urban communities
- Attaches to mucosa but does not invade
- May cause endoscopic duodenal nodularity (Indian J Pathol Microbiol 2011;54:312)
- Causes epithelial barrier dysfunction by down regulating claudin1 and increasing epithelial apoptoses (Gut 2007;56:328)
Terminology
- Giardia duodenalis, also known as G. lamblia, G. intestinalis (Pritt: Creepy Dreadful Wonderful Parasites Blog - Answer to Case 508 [Accessed 17 October 2018])
Diagrams / tables
Images hosted on other servers:
Life cycle
Diagnosis
- Detect cysts, trophozoites or antigens in stool
Gross images
Contributed by Centers for Disease Control and Prevention
Giardia
Microscopic (histologic) description
- Variable villous blunting, increased inflammatory cells, organisms are teardrop (pear) shaped with paired nuclei in lumen between villi
- Size of organism is similar to enterocyte nuclei
Microscopic (histologic) images
Contributed by Bobbi Pritt, M.D. and Emily Fernholz
Trichrome stained stool specimen, Giardia duodenalis
Contributed by Bobbi Pritt, M.D.
Giardia
Case #157
Giardial trophozoites
along the surface of
foveolar epithelial cells
Sickle shaped trophozoites
Videos
"Falling leaf" motion of trophozoite
