Lab Test

Stain, Microsporidium

Brachiola, Encephalitozoon, Nosema, Pleistophora, Enterocytozoon, TrachipleistophoraVittaforma, Microsporidium Stain

Test Codes

Antrim #40439, EPIC: LAB5528, SOFT: STMIC




At least 2 weeks should elapse following barium administration before collection of the specimen.

Specimen Collection Criteria

Collect: One of the following specimen types as described below.

  • Random stool specimen, duodenal aspirate or sputum (sputum acceptable from immunocompromised patients) placed in a transport vial with SAF preservative.
    • Fill the vial until the fluid level reaches the red fill line.
    • Unpreserved stool must be placed in SAF within 2 hours of collection.  
  • Corneal Scrapings: Place scrapings in a sterile collection container with 0.5 mL of sterile, non-bacteriostatic saline.
  • Corneal Swab: Place swab in a sterile collection container with 0.5 mL of sterile, non-bacteriostatic saline.

Physician Office/Draw Specimen Preparation

Maintain all specimens at room temperature (20-25°C or 68-77°F) prior to transport.

Preparation for Courier Transport

Transport: All specimen types in the described appropriate container at room temperature (20-26°C or 68-78.8°F).

Rejection Criteria

  • Solid or formed specimens.
  • Rectal swabs.
  • Specimens in leaking or soiled containers.
  • Specimens containing oil or urine.
  • Specimens that contain toilet water.
  • Specimens received in diapers.
  • Specimens collected within 7 days of the patient taking a laxative.
  • Specimens collected following a soap suds enema.
  • Stools containing barium from a previous radiological procedure.
  • Specimens collected within 14 days following antibiotics.
  • Unpreserved stool greater than 2 hours past collection.
  • Specimens in PVA.
  • Frozen specimens.
  • Testing will not be performed on more than one specimen collected from the same site per patient within a 24 hour period.


Specimen Stability for Testing:

Room Temperature (20-26°C or 68-78.8°F): 2 hours (Unpreserved sputum or stool)
Room Temperature (20-26°C or 68-78.8°F): 4 hours (Corneal scrapings or swab)
Room Temperature (20-25°C or 68-77°F): 7 days (Preserved sputum or stool)
Refrigerated (2-8°C or 36-46°F): 7 days (Preserved sputum or stool)
Frozen (-20°C/-4°F or below): Unacceptable

Specimen Storage in Department Prior to Disposal:

Room Temperature (20-26°C or 68-78.8°F): 7 days


Grosse Pointe sent to Royal Oak Microbiology Laboratory for testing. 
Royal Oak Microbiology Laboratory
Troy sent to Royal Oak Microbiology Laboratory for testing.


Monday – Friday, 7:00 am – 3:30 pm.
Results available within 24-72 hours.

Reference Range

No Microsporidium seen.

Test Methodology

Concentration, stain, microscopic examination.


Infection with Microsporidium can be documented by identification of organisms in biopsy, corneal scraping, fecal or sputum specimens. Identification for classification purposes and diagnostic confirmation of species requires the use of transmission electron microscopy (1).

Clinical Utility

This assay aids in the diagnosis of microsporidiosis.

Clinical Disease

Microsporidia are intracellular protozoa. The following common genera, MicrosporidiumEncephalitozoon and Enterocytozoon and uncommon genera, Brachiola, Nosema, Pleistophora, Trachipleistophora, Vittaforma infect humans and may cause microsporidiosis. Patients with intestinal infection have watery, non-bloody diarrhea. Fever is uncommon. Intestinal infection is most common in immunocompromised individuals, especially those who are infected with HIV. The clinical course is complicated by malnutrition and progressive weight loss (1).


Enterocytozoon bieneusi and Encephalitazoon (septala) intestinalis are important causes of chronic diarrhea in patients with HIV infection. Additional clinical syndromes associated with other Microsporidium genera in HIV-infected patients include keratoconjunctivitis, nephritis, hepatitis, and peritonitis, but they occur infrequently. Information about the epidemiology and mode of transmission is limited (1). Microsporidiosis is an emerging infection of both immunocompromised and immunocompetent individuals (2).

Incubation Period

Unknown (1).


In animals, transmission occurs by ingestion of Microsporidium spores in food or contact with spores shed into the environment through stools or urine. In humans, fecal-oral contact may play a role in transmission (1).


    1. Garcia, L.S. 2007. Intestinal Protozoa (Cocciidia, Microsporidia) and Algae. Diagnostic Medical Parasitology. 4th ed. ASM Press, Washington, D.C.
    2. Garcia, L.S. 2016. Special Stains for Microsporidium. Leber, A.L., Editor-in-Chief, Clinical Microbiology Procedures Handbook, 4th ed. ASM Press. Washington, D.C.
    3. Weber, R., P. Deplazes, and A. Mathis, 2015. Microsporidia. In: Jorgensen, J., et. al. eds., Manual of Clinical Microbiology, 11th ed. ASM Press. Washington, D.C., p. 2209-2219.

      CPT Codes

      87015, 87207.


      Last Updated


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