Ova and Parasites Complete
O and P, O&P, parasites, Entamoeba, hookworm, amoebae, Strongyloides, Schistosomiasis, tapeworm, roundworm, Ova and Parasite Examination
Test Codes
EPIC: LAB9550
Department
Microbiology
Instructions
New restrictions are in place for ordering the Ova and Parasites test:
Cryptosporidium/Giardia are the most common parasites found in patients with acute diarrhea in the United States. Providers are encouraged to order the Giardia/Cryptosporidium Antigen Screen that detects Giardia duodenalis and Cryptosporidium spp. antigens prior to ordering the Ova and Parasites test.
If concerned about possible infection with Cyclospora, Cystoisospora, or Microsporidium, please order these tests separately.
Specimen Collection Criteria
If submitting specimens suspected of being worms or worm segments, place the specimen in 70% alcohol or formalin. Worms should be cleaned of stool prior to submission.
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 up to three specimens within a 5–7 day period per patient. Specimens should be collected 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).
Collect: Random stool specimen (2.0 g or 2.0 mL) immediately placed in a vial containing EcoFix preservative to prevent parasite deterioration.
- Unpreserved stool must be received in the Laboratory within 1 hour of collection to be tested.
Physician Office/Draw Specimen Preparation
Maintain stool in EcoFix preservative at room temperature (20-26°C or 68-78.8°F) prior to transport.
Preparation for Courier Transport
Transport: Stool in EcoFix 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 (4) days.
- No risk factors or no prior negative Giardia/Cryptosporidium Antigen Screen.
- No Comprehensive Ova and Parasite Review Approval Form with a documented negative Giardia/Cryptosporidium screen – Giardia/Cryptosporidium Parasite Antigen Screen will be performed instead.
Inpatient Specimen Preparation
Stool not placed in EcoFix preservative must be received in the Laboratory immediately (within 1 hour) after collection.
In-Lab Processing
Unpreserved stool must be placed in EcoFix preservative or tested within 1 hour of collection.
Storage
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): 9 months (preserved)
Refrigerated (2-8°C or 36-46°F): 9 months (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
Laboratory
Giardia/Cryptosporidium screen: Royal Oak Microbiology Laboratory
Ova and Parasite Complete: This test is sent to ARUP Laboratories, Salt Lake City, UT.
Performed
This test is sent to ARUP Laboratories, Salt Lake City, UT.
Results available within 3 – 4 business days.
Reference Range
No ova or parasites seen.
Test Methodology
Method for identification of ova and parasites includes wet mount and trichrome stain.
Interpretation
The routine ova and parasite test detects a variety of intestinal parasites.
If concerned about possible infection with Cyclospora, Cystoisospora, or Microsporidia, please order these tests separately.
Interpretation
The routine ova and parasite test detects a variety of intestinal parasites.
If concerned about possible infection with Cyclospora, Isospora, or Microsporidium, please order these tests separately.
If Cryptosporidium, Cyclospora, Isospora, or Microsporidium are seen on Ova and Parasite examination a modified acid-fast stain will be performed.
Clinical Utility
The Ova and Parasites test has limited clinical utility in the Corewell Health patient population. Instead, providers are encouraged to order the Giardia/Cryptosporidium Antigen Screen that detects Giardia duodenalis and Cryptosporidium spp. antigens, which are the most common parasites found in patients with acute diarrhea in the United States.
If Ova and Parasite testing is warranted, this test can aid 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.
Reference
- Ova and Parasite Exam, Fecal (Immunocompromised or Travel History), ARUP Laboratories.
- Garcia, L.S. 2007. "Collection, Preservation, and Shipment of Fecal Specimens. Diagnostic Medical Parasitology, 5th edition. ASM Press. Washington, D.C.
- Miller, J. Michael. 1996. A Guide to Specimen Management in Clinical Microbiology, ASM Press, Washington, D.C. pp. 39-43.
- Siegel, D.L. et al, 1990, Inappropriate Testing for Diarrheal Diseases in the Hospital. JAMA. 263:979-982.
- Carroll, M.J., 2016. Collection, and Preservation of Fecal Specimens, Clinical Microbiology Procedure Handbook. ASM Press, Washington, D.C.,
CPT Codes
87177, 87209.
Contacts
Microbiology Laboratory – RO
248-551-8090
Name: Microbiology Laboratory – RO
Location:
Phone: 248-551-8090
Last Updated
8/27/2025
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