Laboratory Test Information Guide

Details for Ova and Parasite Screen

Test Name: Ova and Parasite Screen
Alternate Name(s):  
Laboratory: Microbiology (VH)
Specimen Type: Faeces

See Critical Information Required before submitting samples.
For samples other then faeces, contact the lab before collecting for specific instructions regarding preservation and transport.
Collection Information: Submit sample in ova and parasite kit, which consists of two containers; one for stool and one for stool with preservative. Both containers must be submitted.

Outpatients shall follow instructions included with collection containers.

Collect specimen prior to administration of antibiotics or antidiarrheal agents. Avoid use of mineral oil, bismuth and barium prior to collection.

Avoid contamination with urine or water from the toilet.

Select areas of stool that appear blood-stained, purulent or watery. Transfer a 5 mL portion to parasite transport media (labelled SAF FIXATIVE). Thoroughly mix 5 mL of stool with the 20 mL of fixative (1:4 ratio).

Send this preserved stool and also a portion of unfixed stool to the lab.
Test Schedule: Daily

If full Ova and Parasites requested, the sample will be referred out Monday-Friday
Turnaround time from when specimen
is received in testing laboratory:
1 day-for Ova & Parasites Screen
2 weeks for full Ova & Parasites
Reference Range:  
Effective Date: 2011-07-21
Revised Date: 2020-02-12
Critical Value:  
Interpretive Comments: Samples are screened for Giardia species, and Cryptosporidium species.
Special Processing: For full parasite investigation , clinical data and travel history must be included.
A total of 3 specimens should be collected every other day and submitted.
Method of Analysis: Microscopic analysis
Enzyme Immunoassay
Critical Information Required: The online screening questionnaire MUST BE COMPLETED and accompany the sample. If a request is received without a questionnaire, screening will not be performed. If risk factors are not present, the specimen will not be processed for ova and parasites.
OAP Screening Questionnaire

Patient must have diarrheal illness for >7 days with negative stool culture
PLUS one of the following risk factors:
1. Long Term Care resident with documented outbreak
2. Day Care Worker
3. Previous documented parasitic infection
4. Other risk factors please specify
For Full OAP Testing
1. The patient must be immune-compromised and one of the following risk factors:
a. HIV positive
b. Long Term Immunosuppressive Drugs
c. Post Organ Transplant
d. Other
3. Travel History Outside of N. America and or European Union
4. Immigrant from countries with high parasite prevalence rate
Storage & Shipment: The specimen must be refrigerated.

The specimen must be received within 24 hours of collection.
System Codes: 
Referred To: If a full Ova and Parasites Investigation is requested, based on clinical information, the sample will be sent to:

Dynacare Medical Laboratories
London Public Health Laboratory

Questions? Comments? Contact Laura Gopaul