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Ova and Parasites

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

Test Codes

EPIC: LAB5519

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 Ova and Parasite 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, Isospora, or Microsporidium, please order these tests separately.

Specimen Collection Criteria

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 (3) specimens on alternate days or every third day 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 (approximately half an ounce), immediately placed in a vial containing EcoFix preservative to prevent parasite deterioration.

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 Ova and Parasite Antigen Screen.
  • No Comprehensive Ova and Parasite Review Approval Form - Ova and 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): 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

Laboratory

Royal Oak Microbiology Laboratory

Performed

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.

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 Beaumont Health patient population. Instead, providers are encouraged to order the Ova and Parasite 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

  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.

Contacts

Last Updated

4/4/2024

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