Aquavetplan enterprise Manual Version 0, 2015

A2 Management of aquatic animal disease emergencies

The links and lines of communication that may be used during the management of an aquatic animal disease emergency are summarised in Figure 1.

Figure 1 Links and lines of communication during an aquatic animal disease emergency

Aq CCEAD = Aquatic Consultative Committee on Emergency Animal Diseases; CSIRO-AAHL = Commonwealth Scientific and Industrial Research Organisation Australian Animal Health Laboratory; CVO = chief veterinary officer; OIE = World Organisation for Animal Health

A2.1 Reporting

In most states and territories, fish kills are most likely to be reported initially by either farmers or members of the general public. These people will inform research institutes, private consultants, private veterinarians, fisheries officers, field officers or the state veterinary diagnostic laboratory directly.

Regardless of the avenue of reporting, it is imperative that the state or territory veterinary laboratory, or equivalent, is informed as soon as possible so that appropriate action is initiated; the state or territory government will be responsible for coordinating the response. However, in some states, investigation of fish kills may initially be the responsibility of a department other than the one that will coordinate the response—for example, the environment department. In these cases, prompt and transparent communication between the relevant government departments is necessary to determine whether a fish kill is due to a contagious disease or other causes, such as adverse environmental conditions or pesticide contamination.

A2.2 Coordination of the incident

Management of the incident is coordinated by the state or territory authority (agriculture or fisheries department)—usually through a single state or territory veterinary diagnostic laboratory (or equivalent), led by the jurisdiction’s chief veterinary officer (CVO) and/or director of fisheries (DF). The state authority has links to other emergency agencies that may be mobilised in an emergency disease outbreak.

A2.3 Lines of communication during the incident

The state CVO, DF or delegates are the conduit for information within the state or territory to other jurisdictions and with Australian Government agencies. If the disease is of national importance, the CVO or DF will activate the Aquatic Consultative Committee on Emergency Animal Diseases (AqCCEAD). This committee is a communication network comprising the representatives from the Australian Government Department of Agriculture, CVOs or DFs, and the CSIRO Australian Animal Health Laboratory (CSIRO-AAHL). The AqCCEAD is chaired by the Australian CVO.

In an outbreak of a disease of national or international significance, the AqCCEAD is the central authority for communications both within Australia and to international agencies. The Australian CVO, on behalf of Australia, will carry out international communication. The Office of the Australian CVO is responsible for international reporting to the OIE. Reportable diseases are only reported after confirmation by the AqCCEAD, after the committee has considered the available evidence.

A2.4 A team approach

A taskforce or disease emergency management team may be formed. This team would include personnel with expertise relevant to the specific outbreak; therefore, the composition of the team will depend on the nature of the emergency. Industry representatives should play a key role in the taskforce.

The assistance of other agencies may be required to cope with issues such as public health, environmental protection and field operations. Such agencies could include the state emergency services, police, the environmental protection agency and the health department. Liaison with these services will be largely at the taskforce level, although links at a higher level will often be forged by the AqCCEAD to secure cooperation.

Teamwork between state or territory departments, national agencies and industry representatives is essential to effectively use the limited resources available for management of aquatic animal disease emergencies.

A2.5 Information management

Control of information and communication is important. Timely release of accurate information is the key to good information management. The aim is to keep relevant parties informed, reduce the spread of inaccurate information by rumour, and protect any appropriate trade position (domestic or international).

A2.6 Disease management in aquatic environments

Establishment of DMA boundaries during an aquatic animal disease emergency presents difficulties that normally do not arise in terrestrial animal disease control. Water movement through and around farms, within streams or rivers, and in the marine environment leads to a substantial risk of disease spread through transfer of infectious pathogens in the water column, movement of infected material (particularly on suspended organic and inorganic matter) and movement of infected wild organisms.

For example, although an infected area may be established around an individual land-based hatchery or farm, water bodies adjacent to the infected area and in the same catchment should be considered for monitoring and control measures. DMA boundaries around marine farms or wild fisheries may encompass large areas that must take into consideration local currents, natural barriers and the normal range of susceptible wild species.

Establishment of DMA boundaries must take into account dispersal of water discharged from any infected semi-closed aquaculture systems (e.g. hatcheries) or potentially infected processing facilities, and how this enters adjacent water. Outbreaks in semi-open systems (marine farms) require consideration of all oceanographically connected areas and distribution of wild host or vector populations. Spread of infected material through scavenging by other species also needs to be considered.

Thus, rather than property boundaries, the geography, water flow, distance between farming areas and range of susceptible species will define where DMA boundaries are placed.

In some cases (e.g. pelagic fisheries), establishment of infected areas and dangerous contact areas may not be practical or possible, and the disease response may rely primarily on measures applied to activities within the fishery. The Australian outbreak of pilchard herpesvirus during 1998–99 is an example of aquatic disease affecting wide-ranging wild fisheries. In this case, it was not possible to establish an effective restricted area, and control measures relied primarily on restrictions applied to commercial fishing activities in control areas.

Establishment of DMA boundaries and their classification must also take into account potential mechanisms by which a pathogen may move beyond these boundaries. In most circumstances, it is advisable to overestimate the size of DMAs and reduce their area as the response takes effect. In the initial response, DMA boundaries will usually need to include the whole of a catchment area in freshwater systems, and complete bays or regions in marine environments.