Legionella spp. – Swab

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.

Specimen Collection and Handling

Specimen Requirements

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

Legionella spp.1



Environmental swab

Submission and Collection Notes


Swab samples are not routinely tested for Legionella spp.  This test is available for investigations and/or outbreaks with a culture confirmed clinical case(s) of Legionella spp..  For the ‘Confirmed Etiological Agent’, record “Legionella” in the space provided.  The laboratory should be contacted prior to submission of samples.

Special Instructions

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

Shipping Instructions:

  • Ship all foods 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. FOOD SAMPLES on the outside of the container. 
  • DO NOT SHIP WITH CLINICAL SPECIMENS.  Shipping containers used for food samples should be dedicated to food samples and not be used for other types of environmental samples. 
  • Ship dry foods and other shelf stable foods at ambient temperature in a closed container. 
  • Ship frozen foods in an insulated container with sufficient ice packs to maintain the frozen state. 
  • Ship perishable foods in an insulated container with sufficient cold packs to maintain a temperature as close to 4°C as possible. If ice is used, contain the ice in a manner that does not allow water contact with the samples.
  • Submit all food 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.

Turnaround time is up to 14 days.

Test Methods

The presence of Legionella spp. in a swab sample is determined by the culture method by isolation on selective agar plates, followed by biochemical and serological identification. Results are reported as Detected with the specific Legionella spp. or Not detected. (Public Health Ontario Laboratory Method)


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

If Legionella was isolated from an environmental sampling site in connection to an outbreak investigation and is a match to the clinical case, remediation is required and consultation with PHO Laboratory microbiologist is recommended.

If Legionella was isolated and is not a match to the clinical case, remediation may be required and PHO Laboratory microbiologist is available for consultation.


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

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.

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Laboratory Services


Updated 19 Jan 2023