Influenza – Respiratory

Testing Indications

Public Health Ontario Laboratories (PHOL) utilizes different testing algorithms for influenza and other respiratory viruses during the winter and summer seasons.

Refer to the current labstract on respiratory viral testing titled: LAB-SD-121, Respiratory Viral Testing Algorithm for detailed information about the testing method that will be performed based on patient setting and time of year. 

Specimen Collection and Handling

Specimen Requirements

Test Requested Required Requisition(s) Specimen Type Minimum Volume Collection Kit

Respiratory Virus Culture

Nasopharyngeal swab, or throat swab

1 swab in the collection kit media

Virus-Respiratory Collection Kit order# 390082

Respiratory Virus Culture

Bronchial Alveolar Lavages (BAL), or pleural fluid

2.0 ml

Sterile container

Respiratory Virus Culture

Respiratory tract tissue

1.0 g

Sterile container

Submission and Collection Notes

1

Follow the instructions on the Virus – Respiratory Collection Kit

2

Complete the following on the General Test Requisition Form. Ensure the following fields are completed if diagnostic testing is requested:

  • patient setting
  • symptoms
  • onset date
3

Patient setting must be provided to help triage specimens. If patient setting is not provided, sample will not be tested.

4

CMV PCR for bronchial alveolar lavage (BAL)/bronchial wash/pleural fluid will be done if requested on the requisition.

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.

Place specimen container in the biohazard bag and seal bag, and insert the completed requisition in the pocket on the outside of the sealed biohazard bag. Specimens should be stored at 2-8°C following collection and shipped to PHO laboratory on ice packs.

Requisitions and Kit Ordering

Test Frequency and Turnaround Time (TAT)

Respiratory virus testing is performed daily Monday to Saturday.

The turnaround time for Influenza A/B PCR is up to 2 days after receipt by PHO laboratory.

The turnaround time for rapid respiratory virus culture (R-Mix TOO) is up to 4 days.

Samples tested by traditional virus culture are observed for a minimum of 17 days prior to reporting a negative culture result; samples that are positive can be observed at any point during this period.

Turnaround time for traditional virus culture is up to 18 days.

Turnaround time will vary during the winter months.

Reporting

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

Specimens that are positive for adenovirus from Outbreaks are reported to the Medical Officer of Health as per Health Protection and Promotion Act.

Test Methods

The Rapid Viral Culture system (R-Mix Too) detects:

  • adenovirus
  • influenza A
  • influenza B
  • respiratory syncytial virus (RSV)
  • parainfluenza 1, 2 and 3,
  • human metapneumovirus

Algorithm

Public Health Ontario laboratories utilizes different testing algorithms for influenza and other respiratory viruses during the winter and summer seasons.

The winter algorithm usually takes effect the first Monday of November and remains in effect until the first Sunday of May. 

The summer algorithm usually takes effect the first Monday of May and remains in effect until the first Sunday of November. 

Exact effective dates may vary due to influenza activity in the community during the transition time periods.

Testing changes from winter to summer.

Patient Setting1 Winter Summer
In-patient ICU/CCU2

Influenza A/B RT PCR (and subtype if flu A is positive).

If flu A or B is positive then no further testing will be performed. If flu A/B is negative, samples will be further tested by Rapid Viral Culture3,4 

Rapid Viral Culture3,4

Inpatient ward/Institutions

Influenza A/B RT PCR (and subtype on a selection of flu A-positive specimens).

If flu A or B is positive then no further testing will be performed. If flu A/B is negative, samples will be further tested by Rapid Viral Culture3

Rapid Viral Culture3

Institutional Respiratory Infection Outbreaks

Influenza Rapid Testing up to 4 outbreak samples.

Influenza A/B RT PCR (1 sample from each flu A-positive outbreak will be subtyped).

If flu A or B is positive then no further testing will be performed. If flu A/B is negative, samples will be further tested by Rapid Viral Culture3

Influenza Rapid Testing up to 4 outbreak samples.

Influenza A/B RT PCR (1 sample from each flu A-positive outbreak will be subtyped).

If flu A or B is positive then no further testing will be performed. If flu A/B is negative, samples will be further tested by Rapid Viral Culture3

Emergency Room patients5

Testing not available6

Testing not available6

Ambulatory –  influenza high risk patients5

Testing not available6

Testing not available6

Ambulatory – patients NOT influenza high risk5

Testing not available6

Testing not available6


1Patient setting must be provided to help triaging of specimens. If patient setting is not provided, sample will NOT be tested.
2ICU - Intensive Care Unit; CCU - critical care units.
3The Rapid Viral Culture system (R-Mix Too) detects:  adenovirus, influenza A, influenza B, respiratory syncytial virus (RSV), parainfluenza 1, 2 and 3, and human metapneumovirus.
4CMV PCR for bronchial alveolar lavage (BAL)/bronchial wash/pleural fluid will be done if requested on the requisition.
5Respiratory swab collection kits will not be supplied for these patient settings.
6To assist with patient management when respiratory viral testing is not available, healthcare providers are encouraged to refer to PHO’s respiratory surveillance reports for information on respiratory pathogen activity in Ontario.

Data and Analysis

contact lab

Contact Laboratory Customer Service

Laboratory Services

customerservicecentre@oahpp.ca

Updated 15 Feb 2019