Process for developing and reviewing surveillance case definitions

The Communicable Diseases Network Australia (CDNA) follows a process to develop and review case definitions for all nationally notifiable diseases.

About surveillance case definitions

The Communicable Diseases Network Australia (CDNA) develops surveillance case definitions for every nationally notifiable disease, and reviews existing ones if needed.

State and territory health departments use these definitions to decide whether to report a case to the National Notifiable Diseases Surveillance System (NNDSS).


Working group

The CDNA creates a small working group of experts to develop or revise the case definition. The working group then:

  • writes a draft (for a new definition) or identifies what changes are needed (for a revision)
  • ensures the new definition or changes are in line with the laboratory case definition or outlines any differences
  • consults with the CDNA’s Public Health Laboratory Network (PHLN) representative or the custodian of the laboratory case definition
  • considers other guidance and research, including the relevant CDNA national guidelines (if any) and international case definitions
  • prepares a paper for the CDNA, including proposed changes, explanation and evidence.

If the working group can’t reach a final consensus and endorsement, they will prepare a paper for CDNA summarising the issues and options. The PHLN representative will assess whether the PHLN needs to consider these options before they go to the CDNA.

PHLN consideration and endorsement

The PHLN will consider the case definition, with a 2-week consultation period.

The PHLN will:

  • consult with relevant stakeholders
  • inform the working group whether to send the case definition to other groups for information, once final.

The PHLN then takes one of the following actions:

  • Provides feedback for the working group to address.
  • Endorses the case definition.

The working group then sends the revised or proposed new case definition to the CDNA.

CDNA consideration and endorsement

The CDNA will consider the working group’s paper. The CDNA then takes one of the following actions:

  • Endorses the case definition.
  • Makes minor changes.
  • Does not endorse, and refers the case definition back to the working group.

Once the CDNA endorses the case definition, we will publish it in Communicable Diseases Intelligence and in our collection of surveillance case definitions.  

It then becomes effective from a specific date.

Role of the states and territories

State and territory central disease control units introduce the revised or new case definitions in their jurisdictions.

If a state or territory changes the content of a case definition, or the date it becomes effective at a jurisdictional level, they must let us know. This ensures we can correctly interpret national data.

Read final case definitions

We have grouped the case definitions into a collection.

CDNA surveillance case definitions

This collection contains surveillance case definition documents for nationally notifiable diseases within Australia. The Communicable Diseases Network Australia (CDNA) created these definitions to help health professionals decide whether to notify authorities of a case.


Contact the CDNA secretariat with any questions about this process.

Communicable Diseases Network Australia (CDNA) secretariat

Contact the CDNA secretariat for more information about the network's activities.
Date last updated:

Help us improve

If you would like a response please use the enquiries form instead.