An epidemiologic model of koi herpesvirus (KHV) biocontrol for carp in Australia

Abstract

In Australia, the common carp (Cyprinus carpio) is a significant pest species because it dominates fish communities in numerous catchment areas. In 2016,Australia launched a national control plan based on the use of Cyprinid herpesvirus 3 (CyHV3) to reduce carp densities. CyHV3 is exotic to Australia and is listed as by the World Organization for Animal Health (OIE) due to its substantial impact on global aquaculture production. Infection with CyHV3 causes koi herpesvirus disease (KHVD), a high mortality disease in common carp affecting all age classes of both wild and farmed fish.The objective of this review was to consider the current knowledge of CyHV3 transmission factors and discuss the potential for recurring epidemic-level mortality events in carp found in Australia. Case studies were presented comparing KHVD outbreaks in wild carp in Japan and Epizootic haematopoietic necrosis virus (EHNV) outbreaks in pest redfin perch (Perca fluviatilis L.) in Australia. The release of CyHV3 in thermally-favourable waterways in Australia would undoubtedly cause one high mortality KHVD epidemic. However, there is little evidence to suggest that repeated CyHV3 outbreaks would recur at a magnitude to counter the reproductive potential of the surviving carp.