Lab Test

Ova and Parasites

O and P, parasites, Giardia, Entamoeba, hookworm, amoebae, Echinococcus, Strongyloides, Schistosomiasis, tapeworm, roundworm, Ova and Parasite Examination

Test Codes

Antrim #42309, EPIC: LAB5519, SOFT: OP


  • If concerned about possible infection with Cryptosporidium, Cyclospora, Isospora, or Microsporidium, please order these tests separately.
  • One of the most important steps for diagnosing intestinal parasitic diseases is proper specimen collection. Improperly collected specimens and unpreserved specimens delayed in transport may result in inaccurate laboratory results.
  • Collect the specimen prior to giving the patient antibiotics or antidiarrheal agents. Do not use barium, mineral oil or magnesium. If these agents are used, delay collection of the fecal specimen for a minimum of 7 days (following antidiarrheal agents) to 14 days (following antibiotics).
  • Ova and parasites will NOT be performed on inpatients hospitalized greater than 4 days.  Exceptions will be granted on a case-by-case basis.  Please contact the Medical or Technical Director of the Microbiology Laboratory. 
  • Collection of specimens should be limited to three (3) specimens collected on alternate days or every third day per patient.

Specimen Collection Criteria

Collect: Random stool specimen (approximately half an ounce), immediately placed in a vial containing SAF preservative to prevent parasite deterioration.

Physician Office/Draw Specimen Preparation

Maintain stool in SAF preservative at room temperature (20-26°C or 68-78.8°F) prior to transport.

Preparation for Courier Transport

Transport: Stool in SAF preservative, at room temperature (20-26°C or 68-78.8°F).

Rejection Criteria

  • Dried, hard 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 1 hour past collection.
  • Specimens that exceed the 3 samples per patient per diarrheal episode recommendation (see above).
  • Specimens collected on inpatients hospitalized greater than four days.

Inpatient Specimen Preparation

Stool not placed in SAF preservative must be received in the Laboratory immediately (within 1 hour) after collection.

In-Lab Processing

Unpreserved stool must be placed in SAF preservative or tested within 1 hour of collection.


Specimen Stability for Testing:

Room Temperature (20-26°C or 68-78.8°F): 1 hour (Unpreserved)
Room Temperature (20-25°C or 68-77°F): 7 days (Preserved)
Refrigerated (2-8°C or 36-46°F): 7 days (Preserved)
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


Farmington Hills sent to Royal Oak Microbiology Laboratory for testing.
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 3-4 business days.

Reference Range

No ova or parasites seen.

Test Methodology

Concentration techniques and trichrome staining of smear.


The routine ova and parasite test detects a variety of intestinal parasites. If Cryptosporidium, Cyclospora, Isospora, or Microsporidium species are suspected, please order the specific test separate from the routine Ova and Parasite examination. If they are seen on Ova and Parasite examination a modified acid fast stain will be performed.

Clinical Utility

This assay aids in the detection and identification of protozoa, eggs, larvae, and adult helminths (worms) or segments (proglottids) of tapeworms.

Clinical Disease

Parasitic protozoa and helminths of various types may inhabit the intestinal tracts of humans. Protozoa may cause diarrhea and/or malabsorption by elaborating toxins or by adhering to or invading the mucosa or by unknown mechanisms. Helminths may obstruct the intestine, cause blood loss, or may interfere with the absorption of essential nutrients. Larva or eggs may disseminate beyond the intestine and cause tissue destruction and provoke inflammation. Diarrhea, malnutrition, anemia, and intestinal obstruction are some of the consequences of infection with intestinal parasites.


  1. Garcia, L.S. 2007. "Collection, Preservation, and Shipment of Fecal Specimens. Diagnostic Medical Parasitology, 5th edition. ASM Press. Washington, D.C.
  2. Miller, J. Michael. 1996. A Guide to Specimen Management in Clinical Microbiology, ASM Press, Washington, D.C. pp. 39-43.
  3. Siegel, D.L. et al, 1990, Inappropriate Testing for Diarrheal Diseases in the Hospital. JAMA. 263:979-982.
  4. Carroll, M.J.,  2016. Collection, and Preservation of Fecal Specimens ,Clinical Microbiology Procedure Handbook. , ASM Press, Washington, D.C.,

CPT Codes

87177, 87209.


Last Updated


Microtainer® and Vacutainer® are registered trademarks of Becton, Dickinson and Company.
UroVysion® is a registered trademark of Abbott Laboratories. ThinPrep® is a registered trademark of Hologic, Incorporated.


This directory currently reflects information only for specimens collected and/or processed at the
Farmington Hills, Grosse Pointe, Royal Oak, and Troy campuses.