Microsporidiosis
From Anvita Health Wiki
Contents |
Etiology
Epidemiology
- Microsporidia infest a large variety of animals, including humans, but reservoir hosts have not been identified
- serious pathogens in immunocompromised hosts
- may account for 30% of unexplained diarrhea in AIDS patients
Pathology
- organisms multiply intracellularly ( merogony)
- spores are formed ( sporogony) that rupture the host cell ( duodenal enterocyte) & infect adjacent cells or are passed in the feces
- spore contains a coiled polar tubule which is extruded to penetrate the membrane of the recipient cell
- the sporoplasm is injected through the tubule into the cytoplasm of the host cell, where it multiplies
Clinical-manifestations
- chronic diarrhea ( mean duration 8.5 months)
- weight loss
- dissemination (some species)
- malabsorption
- hepatic, ocular, CNS, muscle manifestation (other species)
Laboratory
-
- Uvitex 2B
- calcofluor white
- may be more sensitive than modified trichrome staining
- small size of spores makes detection difficult
- small bowel biopsy
- trichrome, Brunn & Brenn, or Giemsa stain
- electron microscopy for species identification
- fecal fat may be positive
- abnormal D-xylose absorption test
- serum albumin is generally normal
Management
- no definitive therapy
- albendazole 400 mg QD for 1 month for intestinal disease
- fumagillin may be effective for keratoconjunctivitis
More General Terms
Additional Terms
References
Medical Knowledge Self Assessment Program (MKSAP) 11, American College of Physicians, Philadelphia 1998
