Small intestine & ampulla
Infectious disorders

Topic Completed: 1 August 2012

Minor changes: 19 November 2020

Copyright: 2003-2021,, Inc.

PubMed Search: Microsporidia small bowel

Hanni Gulwani, M.B.B.S.
Page views in 2020: 1,579
Page views in 2021 to date: 669
Cite this page: Gulwani H. Microsporidia. website. Accessed May 6th, 2021.
Definition / general
  • Caused by Enterocytozoon bieneusi, an obligate intracellular protozoan that affects only enterocytes and Encephalitozoon intestinalis, which infects macrophages, fibroblasts, endothelial cells, enterocytes
  • Both cause chronic diarrhea in patients with immunosuppression, HIV
  • Stool examination, PCR
Case reports
  • Albendozole for E. intestinalis, nothing for E. bieneusi
Microscopic (histologic) description
  • Minimal / no changes in mucosa but can find development spores as 1.5 mm dots in enterocytes
  • May be surrounded by halos
  • Also nucleated sporont present as 3 - 5 micron, rounded, basophilic structure often surrounded by a halo
Microscopic (histologic) images

Images hosted on other servers:

Various images

Positive stains
Electron microscopy description
  • Often helpful for diagnosis
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