Viral diseases are among the most important of all health issues in aquaculture and fisheries. Their rapid and accurate recognition is central to the prevention of spread and the control of emerging diseases. Morphological diagnosis based on gross pathology, histopathology and electron microscopy remain vital in the diagnostic process, and are essential to complement accurate molecular aetiolgical diagnosis. Practitioners of morphological diagnosis are becoming scarce, and this application enables knowledge transfer from one of the world's foremost experts, Dr Teruo Miyazaki from Japan. This knowledge transfer requires a hand-on approach in a small group setting, using a multiheaded microscope with plenty of opportunity for discussion. for this reason a face-to-face visit is essential. Improving aquatic animal health diagnostic capacity is a priority for FRDC specifically to prevent and manage disease incursions, and to develop diagnostic procedures and techniques to rapidly detect and identify pathogens. This is also a priority for state jurisdictions.

In addition to viral diseases, Dr Miyazaki has career long expertise in general fish pathology, so his visit presents diverse opportunities for continuing education of Australian aquatic animal health diagnosticians.

In FRDC 2007/007 and FRDC 2009/044, it was determined that ornamental fish entering Australia are a source of exotic pathogens, such as cyprinid herpesvirus 2 (CyHV2). This is of particular relevance for goldfish, where domestic breeders claim that their stock succumb to CyHV2 disease when brought into contact with imported goldfish in wholesale and retail premises. CyHV2 only affects goldfish and was addressed in the 1999 IRA as being exotic to Australia. Recent research findings from FRDC 2009/044 indicated that CyHV2 is present in domestic Australian goldfish populations. On 1 September 2011, Biosecurity Australia amended the health certification requirements for the importation of goldfish and no longer requires fish to be certified free of CyHV2.

The detection of CyHV2 and other exotic aquatic pathogens (e.g. gourami iridovirus) was achieved through the application of molecular techniques, such as PCR. Correctly applied and interpreted, molecular approaches offer unique opportunities to understand the local and global spread of a disease. The advancement of molecular approaches is required to safeguard Australia against pathogen incursions through the processes of informed policy development and import risk analysis.

There is a need to disseminate the research that determined that CyHV2 is now established in Australia and how scientific evidence was used to change national biosecurity policy to the international scientific community. There is also a need to ensure the availability of people with specialised training in molecular epidemiology in Australia to stay at the forefront of the application of this technology.