Gastroenteritis –Stool Viruses

Consistent with O. Reg. 671/92 of the French Language Services Act, laboratory testing information on this page is only available in English because it is scientific or technical in nature and is for use only by qualified health care providers and not by members of the public.

*Uncontrolled print copy. Valid only on day of print: 01 May 2024.

Testing Indications

If you suspect poliovirus infection, refer to the test information sheet titled “Poliovirus” for specimen collection and testing information.

If you suspect enterovirus, refer to the test information sheet titled “Enterovirus” for specimen collection and testing information.

Specimen Collection and Handling

Specimen Requirements

Test Requested	Required Requisition(s)	Specimen Type	Minimum Volume	Collection Kit
Gastroenteritis Virus Detection (Molecular)	General Test Requisition	Stool	1.0-2.0 grams	Virus - Enteric Kit order#: 390087

Submission and Collection Notes

Complete the following fields of the General Test Requisition Form if diagnostic testing is requested:

symptoms
onset date
outbreak number if applicable

Refer to the Virus-Enteric Kit Instruction Sheet for detailed specimen collection instructions.

If you suspect an outbreak, contact your local public health unit.

Timing of Specimen Collection

For inpatient, institutional or outbreak specimens, collect within 48 hours of onset when possible.

Collect specimen for all other settings (ER or ambulatory) only if symptoms persist for more than 72 hours.

Limitations

Samples received in Virus or Multi-Organism transport media are not suitable for testing.

Storage and Transport

Label the specimen container with the patient’s full name, date of collection and one other unique identifier such as the patient’s date of birth or Health Card Number.

Place the specimen container in the biohazard bag and seal the bag; insert the completed requisition in the pocket on the outside of the sealed biohazard bag. To maintain optimal viability of the virus, specimens should be stored at 2-8°C following collection and transported to PHO on ice packs within 72 hours of collection. If longer storage/transit time is anticipated, specimens should be frozen at -70°C or lower and transported on dry ice.

Special Instructions

(Include names of all required forms, kit instructions and kit ordering form if PHO provides the kit)

Complete all fields of the PHO General Test Requisition Form: include the requesting healthcare provider's CPSO#, complete mailing address, telephone, and fax number, and the patient’s full name, date of birth, Health Card Number (must match the specimen label), enter the name of the test requested under test description, source of specimen, date of onset, date of collection, physician name and address, and clinical diagnosis. Failure to do so may result in rejection or testing delay.

Requisitions and Kit Ordering

Test Frequency and Turnaround Time (TAT)

Gastroenteritis virus testing is performed Monday to Friday.

Turnaround time is up to 4 days.

TAT will vary during the winter months.

Test Methods

PHO Laboratory uses a laboratory developed multiplex gastrointestinal viral real-time PCR (MGVP) assay which detects and differentiates adenovirus, rotavirus, norovirus GI and norovirus GII.

Note: testing for sapovirus, torovirus and astrovirus are not currently available at PHO Laboratory or the National Microbiology Laboratory.

Algorithm

Public Health Ontario Laboratory utilizes a testing algorithm for gastroenteritis viruses which is based on patient setting.

Gastroenteritis Virus Testing Available at PHOL

Patient Setting¹	Testing
In-patient (ICU/CCU² or ward) Institutions (non-outbreak) e.g. long-term care homes, correctional facilities	MGVP³
Institutional gastrointestinal Infection Outbreaks⁴	MGVP³ for up to 5 outbreak specimens
Emergency Room patients¹	MGVP³ testing is only available if symptoms have persisted for ≥ 72 hours. MGVP³ testing will not be performed if date of onset and date of collection are not provided on the PHO Laboratory requisition
Ambulatory¹	MGVP³ testing is only available if symptoms have persisted for ≥ 72 hours. MGVP³ testing will not be performed if date of onset and date of collection are not provided on the PHO Laboratory requisition

Table Footnotes

Patient setting and duration of symptoms prior to submission must be provided on the requisition to help triaging of specimens. If patient setting and duration of symptoms are not provided the specimen will NOT be tested.
ICU - Intensive Care Unit; CCU - Critical Care Units.
Multiplex gastrointestinal viral real-time PCR (MGVP) detects adenovirus, rotavirus, norovirus GI, norovirus GII.
Note: testing for sapovirus, astrovirus and torovirus are not currently available at PHO Laboratory or the National Microbiology Laboratory.
A limit of 5 outbreak specimens are routinely accepted for testing. Testing will cease once the same gastrointestinal virus is found in two or more samples from the outbreak. For outbreaks with special concerns, including requests for additional testing, contact PHO Laboratory’s Customer Service Centre.

Reporting

Results are reported to the ordering physician or health care provider as indicated on the requisition.

Outbreak specimens that are positive for enteric viruses are reported to the Medical Officer of health as per Health Protection and Promotion Act.

References

Gastrointestinal Virus Testing Update