Legionella spp. – Water

Specimen Collection and Handling

Specimen Requirements

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

Legionella spp.1,2

Water – potable (drinking water) or non-potable (e.g. whirlpools, cooling towers, etc.)

Potable: 10 X 200 mL (to the fill line on the bottle)

Non-potable Water: 10 X 200 mL (to the fill line on the bottle)

PHOL water collection bottle kits (Cat# 300013)

Submission and Collection Notes

1

This test is available for investigations and/or outbreaks with a confirmed clinical case(s) of Legionella spp. Record ‘Legionella’, on the line for ‘Test for Etiological Agent’.  The laboratory must be contacted prior to submission of samples.

2

One litre of water will be used for PCR and one litre will be used for culture for PCR positive and indeterminate test results.

Preparation Prior to Transport

Collect the water sample in PHOL water collection bottles. Collect two litres of water. Ten standard PHOL water collection bottles filled to the fill line will satisfy this requirement. Samples should be stored at refrigeration temperature (2 to 8°C) and shipped to the laboratory as soon as possible.

Special Instructions

For sampling, follow the instructions found in Public Health Inspector’s Guide to Environmental Microbiology Laboratory Testing.

Shipping Instructions:

  • Ship all water in containers with hard walls and lids secured in the closed position. 
  • Shipping containers must be labelled with the submitting organization, unique identifier and contents e.g. WATER SAMPLES on the outside of the container. 
  • DO NOT SHIP WITH CLINICAL SPECIMENS.  Shipping containers used for water samples should be dedicated to water samples and not be used for other types of environmental samples. 
  • Submit all water samples to the laboratory as soon as possible.

Requisitions and Kit Ordering

Test Frequency and Turnaround Time (TAT)

The Legionella test is performed Monday to Friday.

PCR TAT is up to 2 business days. Culture TAT is up to 14 days.

Reporting

Results are reported to the submitting health unit as indicated on the requisition, when all analyses are completed.

Environmental samples that show the presence of bacteria capable of causing illness are reported to the Medical Officer of Health as per the Ontario Health Protection and Promotion Act.

Test Methods

PCR: The presence of Legionella spp. in water is determined by PCR whereby the method detects three targets specific for Legionella species, Legionella pneumophila, and Legionella pneumophila serogroup 1.

Culture: The presence of Legionella spp. in water is determined by the culture method by isolation of the bacterial filtrate on selective agar plates, followed by biochemical and serological identification. Results are reported as Detected with the specific Legionella spp. or Not detected, as appropriate. (modified Centers for Disease Control and Prevention Method)

Interpretation

Legionella is ubiquitous to the environment – water, soil and sediment; and can grow in a wide range of temperatures.

If Legionella is isolated from an environmental sampling site in connection to an outbreak investigation and is a match to the Legionella isolated from the clinical case, remediation is required. Please contact the Environmental Microbiology section at PHO should you require additional information.

If Legionella was isolated and is not a match to the Legionella isolated from the clinical case, remediation may be required. Please contact the Environmental Microbiology section at PHO should you require additional information.

Additional Information

For outbreaks, contact your local Health Unit, your local Public Health Laboratory or the Public Health Ontario, Public Health Laboratory Customer Service at416-235-6556 or1-877-604-4567.

contact lab

Contact Laboratory Customer Service

Laboratory Services

customerservicecentre@oahpp.ca

Updated 9 Dec 2020