A patient with acquired immunodeficiency syndrome and untreated Encephalitozoon (Septata) intestinalis microsporidiosis leading to small bowel perforation: Response to albendazole

Background. - Encephalitozoon (Septata) intestinalis is a common disseminating opportunistic intestinal microsporidian affecting patients with acquired immunodeficiency syndrome. This microsporidian does respond to albendazole therapy. A patient with acquired immunodeficiency syndrome and chronic diarrhea presented George Washington University Hospital in January of 1996. Despite appropriate surgical specimens, no etiology had been found to explain his cholecystitis, cystitis, and enteritis 3 months previously at another hospital. Design. - Tissue specimens were analyzed by light microscopy, using hematoxylin-eosin and the Armed Forces Institute of Pathology Brown-Brenn microsporidia stain, and by transmission electron microscopy. Urine and stool specimens were analyzed by modified chromotrope 2R trichrome and chitin fluorochrome stains and by transmission electron microscopy. Results. - At George Washington University Hospital, disseminated E intestinalis was diagnosed from duodenal biopsy, urine, and stool specimens. On the 14th day of oral albendazole therapy, a partial small bowel resection was performed to correct a perforation (air under the diaphragm). There was no enterocyte microsporidian infection at that time, only spores undergoing macrophage digestion. Review of previous specimens showed severe E intestinalis cholecystitis, cystitis, and enteritis. Albendazole was restarted and, after 2 weeks, the patient had negative stool and urine specimens. Conclusions. - Encephalitozoon intestinalis symptomatically targets many organs, including the urinary bladder. To our knowledge, this is the first tissue-documented case of cystitis. Left untreated with albendazole, small bowel infection can lead to perforation and peritonitis.