National case definition: Campylobacteriosis

Date of last revision/review: December 2023.

National notification

Only confirmed cases of disease should be notified.

Type of surveillance

Routine case-by-case notification to the federal level.

Case classification

Confirmed case

Laboratory confirmation of infection with or without clinical illness:

  • Isolation of Campylobacter spp. from an appropriate clinical specimen (e.g., stool, rectal swab, blood).

Probable case

Clinical illness in a person who is epidemiologically linked to a confirmed case;


Detection of Campylobacter spp. nucleic acid with or without clinical illness, in an appropriate clinical specimen (dependent on the test used), using a nucleic acid test (NAT), such as a polymerase chain reaction (PCR).

Note: Culture may be required for public health and clinical management. Thus culture should be performed on NAT-positive (NAT+) specimens to enable molecular typing (e.g., whole genome sequencing) for surveillance, outbreak detection and response, as per Canadian Public Health Laboratory Network (CPHLN) guidance. An isolate may also be required for antimicrobial susceptibility testing (AST) and/or antimicrobial resistance (AMR) predictions to guide clinical treatment and/or for AMR surveillance.

Note: NAT-positive (NAT+) and culture-negative (culture–) results would still be considered a probable case.

Laboratory comments

Further strain characterization (e.g., whole genome sequencing [WGS]) may be required for epidemiologic, public health, and clinical management.

If more than one target is positive on the gastrointestinal NAT panel, it may be indicative of a cross-reaction, co-infection and/or a single organism harbouring these genes. Reflex culture should be performed to confirm all suspect bacterial NAT signals and to meet requirements for epidemiologic, public health, and clinical management of that organism.

Clinical evidence

Clinical illness may be characterized by the following signs or symptoms: Diarrhea (with blood or mucous), abdominal pain, malaise, fever, nausea and/or vomiting. The severity of illness may vary. While not considered clinical illness, asymptomatic infections may also occur.

ICD code(s)

ICD-11 code(s)

  • 1C40 Campylobacteriosis
  • 1A06 Gastroenteritis due to Campylobacter

ICD-10 code(s)

  • A04.5 Campylobacter enteritis


Probable case definitions are provided as guidelines to assist with case finding and public health management, and are not for national notification purposes.

The use of culture independent diagnostic tests (CIDTs) in clinical settings as stand-alone tests for the direct detection of Campylobacter in stool is increasing.

Common CIDTs include antigen-based tests and molecular nucleic acid tests (NATs). Although the term CIDT is used by other reporting bodies, Canada has used the terms NAT and PCR in their case definitions to exclude antigen-based CIDTs, which currently are not readily used or available for most enteric bacterial pathogens. In addition, there are concerns regarding the accuracy of antigen-based CIDTs for most bacterial enteric pathogens; thus, the specification of NAT/PCR ensures that an antigen test on the clinical specimen is not interpreted as part of a case count. Note: Some reporting bodies may choose to report NAT and PCR results under the term "CIDT", as they are a form of CIDT when directly performed on the clinical specimen.

Specific performance characteristics such as sensitivity, specificity, positive predictive value, and negative predictive value of these assays likely depend on the method used. It is therefore useful to collect information on the type(s) of testing performed for reported cases. However, due to the variable performance characteristics of NAT methods and the potential for clinical sample degradation during transit, discordant results may occur between testing methods and laboratories. It is best practise to culture the NAT positive specimen as soon as possible, such as performing culture in the laboratory that generated the NAT positive signal. When a specimen is positive using a NAT, it is strongly advised to collect and document information on all culture results for the specimen (i.e., NAT+/culture+ versus NAT+/culture– versus NAT+/culture not done); this information is helpful to inform the development and implementation of CIDT and associated case definitions at the provincial, territorial and national levels.

Culture may be required for public health and clinical management. Thus, culture should be performed on NAT+ specimens to enable molecular typing (e.g., WGS) that are required for surveillance, outbreak detection and response. An isolate may also be required for AST and/or AMR predictions to guide clinical treatment and/or for AMR surveillance.

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