Project number: 2021-061
Project Status:
Budget expenditure: $44,801.00
Principal Investigator: Tracey Bradley
Organisation: Agriculture Victoria
Project start/end date: 31 Jan 2022 - 30 Apr 2023


National priority: improving productivity and profitability of fishing and aquaculture.

The development of a guideline to investigate and understand disease outbreaks of unknown cause aligns with AQUAPLAN objectives for 2021- 2026 as per the draft document. The objectives were developed through extensive consultation with industry and government. This project was identified by the Aquatic Animal Health and Biosecurity Subprogram as a priority for the current call for applications.

Aquatic emergency animal disease outbreaks are a substantial threat to aquatic animal production and aquatic environments. The nature of aquatic emergency animal diseases makes them difficult to manage as they are often highly pathogenic and affect both wild and farmed populations. Further, new and emerging diseases are common, and eradication is typically challenging due to the presence of wild reservoir hosts.

Emerging diseases are challenging because reliable diagnostic methods are often not available and epidemiological information to guide responses may be absent. These circumstances present difficulties for decision making and disease investigation because there may be competing priorities between the need to learn about a disease and the need to contain or eradicate it. While the circumstances of each outbreak differ, general principles and approaches apply and if they are documented they can be used to guide responses to emerging diseases.

This project is focussed on developing a guideline to investigate and understand disease outbreaks of unknown cause. The ability to control an outbreak of a disease of unknown cause can occur independently of having knowledge of the aetiological agent. The basic epidemiologic tools used in classical outbreak investigation methodologies can provide insights into factors such spatial, temporal and animal elements of the outbreak. Such approaches are routinely used in terrestrial outbreaks of unknown aetioology and have been instrumental in aiding control, for example the Hendra virus outbreak in horses in the 1990s.

As aquaculture continues to expand at a rate approaching 6% per annum, new diseases will emerge and control strategies will benefit from this approach.


1. Scanning exercise to assess currently available materials in the area of outbreak investigations in aquatic animal diseases (whether cultured or wild).
2. Develop a series of guidelines fit for purpose for a range of stakeholder groups process mapping the steps of an outbreak investigation.
3. Launch the guidelines through the Commonwealth departmental website and create an e-learning module on the Victorian state website - EpiReady ( 2 streams for the 2 stakeholder groups)
4. Assess participants knowledge of how to undertake an outbreak investigation pre and post e-learning module to evaluate the effectiveness of the intervention.


ISBN: 9781760906061
Author: T. Bradley and N. McLaughlin
Handbook • 2023-02-01 • 2.73 MB


This handbook presents guidelines that have been developed to use in the event of a disease outbreak in aquatic animals including finfish, molluscs and crustaceans. For the purposes of these guidelines, in the context of an outbreak, the term “disease” will be used for any event where there are animals that have clinical signs or are dead, irrespective of cause. The approach to determining what is affecting animals will be similar whether the cause is an infectious pathogen or an environmental issue such as a chemical toxin. The outbreak investigation process follows 10 basic steps, but these steps do not necessarily need to be completed in sequence. The information collected will provide the evidence required to conduct an epidemiological investigation. This will aid in understanding if the disease event is an outbreak, what may be causing the disease, what controls to apply and ideally, how to prevent future outbreaks. Clear Information on diagnostic tests and how to submit the best sample possible is provided towards the end of the handbook.

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