Giardiasis: a histologic analysis of 567 cases

Scand J Gastroenterol. 1997 Jan;32(1):48-51. doi: 10.3109/00365529709025062.


Background: The histopathology of the upper and lower gastrointestinal tract of patients with giardiasis as shown by endoscopy with biopsy is ill-defined. We therefore report on 567 cases observed in our institution.

Methods: A retrospective analysis of all cases with giardiasis observed between 1988 and 1994 was performed.

Results: On histologic slides trophozoites were found in duodenal (82.5%) and jejunal (2.1%) mucosa and also in gastric antral (8.7%) and ileal mucosa (12.1%) but rarely in the colon (0.4%). An entirely normal light-microscopic appearance of the duodenal mucosa was found in 462 cases (96.3%). Mild villous shortening and mild inflammation of the lamina propria were observed in duodenal mucosa in 18 subjects (3.7%). In jejunal, ileal, gastric, and colonic mucosa, no Giardia-specific histologic changes were identified. There was a clear male predominance with 347 (61.2%) males and 220 (38.8%) females. Mean age, which was comparable in males and females, was 49.5 +/- 17 years (range, 3-95 years). In 252 Giardia-positive cases gastric biopsy specimens were available, and showed Helicobacter pylori-associated gastritis in 57.8%, reactive gastritis in 10.3%, normal mucosa in 12.9%, chronic atrophic gastritis of the body in 2.9%, and other forms of gastritis in 16.1%.

Conclusions: This study shows that the histology of the small-bowel mucosa is inconspicuous in most subjects with giardiasis. A search for the parasite must therefore be made in all biopsy samples obtained from this area. Furthermore, giardiasis was not associated with a particular gastric disease, such as chronic atrophic gastritis of the body.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Biopsy
  • Child
  • Child, Preschool
  • Diagnosis, Differential
  • Digestive System / parasitology
  • Digestive System / pathology
  • Female
  • Gastritis / complications
  • Gastritis / pathology
  • Giardiasis / complications
  • Giardiasis / pathology*
  • Helicobacter Infections / complications
  • Helicobacter Infections / pathology
  • Helicobacter pylori
  • Humans
  • Intestinal Mucosa / parasitology
  • Intestinal Mucosa / pathology*
  • Male
  • Middle Aged
  • Retrospective Studies
  • Sex Factors