Enteric – Gastroenteritis Viruses
Submission and Collection Notes
Complete the following fields of the General Test Requisition Form if diagnostic testing is requested:
- 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
Samples should be collected within the first 48 hours after onset of symptoms when possible.
Samples received in Virus or Multi-Organism transport media are not suitable for testing for no rotavirus.
Preparation Prior to 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. Failure to provide this information may result in rejection or testing delay.
Specimens should be stored at 2-8°C following collection and shipped to PHO laboratory on ice packs.
If transport of specimen to testing laboratory will be delayed more than 72 hours specimens should be frozen and shipped on dry ice.
Test Frequency and Turnaround Time (TAT)
Enteric virus testing is performed Monday to Friday.
Turnaround time is up to 12 days if tested by traditional virus culture and 3 days if tested by EM.
Turnaround time will vary during the winter months.
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.
Virus cultures are observed for a minimum of 10 days prior to reporting a negative culture result; samples that are positive can be observed at any point during this period.
Most viruses responsible for gastroenteritis in the winter do not grow in cell culture, therefore the following algorithm is applied on a seasonal basis:
Summer stool testing (Mid-April to Mid-December)
- Up to 5 enteric outbreak specimens are screened for norovirus by PCR.
- Further testing (electron microscopy (EM) or virus culture) will be performed on outbreak samples where no virus is detected by norovirus PCR. If Norovirus is detected from two different samples from the same outbreak, no further outbreak testing will be performed.
- Specimens from Day Care Outbreaks and children ≥30 days to < 4 years old are tested by a rotavirus rapid test (Immunochromatographic Test-ICT) or EM.
- Enteric non-outbreak specimens are tested by EM and/or traditional virus culture.
Winter stool testing (Mid-December to Mid-April)
- All stools will be tested by Noro PCR. If Noro PCR is positive then no further testing will take place. If the Noro PCR is negative then EM testing will be performed.