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Test Code OPC Ova and Parasites (O&P), Comprehensive


Note:  Routinely includes Cryptosporidium antigen testing, Giardia antigen testing, a permanent (trichrome) stain examination, and a wet mount examination.

Performing Laboratory

Huntsville Hospital Laboratory

Specimen Requirements

Specimen must arrive within 30 minutes of collection.


Submit stool specimen in a clean, leakproof container. Collect specimen as follows:
1. Lift toilet seat, and cover toilet bowl with a large sheet of plastic wrap. Make a depression in plastic wrap. With toilet seat lowered, pass stool specimen directly onto plastic wrap. (Rectal swab is not acceptable.)

2. Alternatively, collect stool specimen in a clean, dry, wide-mouth container. Do not use toilet paper to collect specimen. Do not remove specimen from toilet water.
3. Specimen may also be submitted in an O&P collection vial supplied. Follow instructions accompanying the vial(s) for collection procedure.
4. Label container/vial(s) with patient’s information, date and actual time of collection, and type of specimen.

5. Forward specimen promptly.

Note:  1. Maximum storage for fresh specimens is 2 hours at ambient temperature. Maximum storage for specimens in an O&P vial at ambient temperature is 2 months or until the expiration date on vial(s), whichever is earlier.

2. Routinely, only 1 stool specimen per day should be collected for O&P testing. After the third hospital day, it is generally recommended that Clostridium difficile toxin testing should be performed on patients with diarrhea, not O&P testing.

3. Specimens will not be processed if transport/storage requirements are exceeded (this will be noted in the report).
4. Contamination of stool specimen with urine or barium is not acceptable.

Reference Values

No ova and parasites to include Giardia and Cryptosporidium.

Day(s) Test Set Up

Monday through Friday

CPT Coding

87177 - wet mount

87209 - trichrome stain

87328 - Cryptosporidium
87329 - Giardia

Secondary ID


LOINC Coding

Test Name LOINC Code

Ova and Parasites (O&P), Comprehensive

Specimen 66746-9