Abstract
Worldwide, viral diseases pose a serious challenge to the fish farming industry and wild fish stocks. In order to prevent the spread of serious fish diseases and to contain and control fish disease outbreaks at a global scale, the World Organisation for Animal Health (OIE) has published relevant data on these fish diseases, both in the Aquatic Animal Health Code (OIE, 2017a), including the OIE listed fish diseases, and in the Manual of Diagnostic Tests for Aquatic Animals (OIE, 2017b), including recommended diagnostic methods. The list of viral OIE notifiable fish diseases currently includes: Epizootic haematopoietic necrosis disease (EHN), Infection with HPR-deleted or HPR0 infectious salmon anaemia virus (ISA), Infection with salmonid alphavirus, causing Pancreas disease (PD) and Sleeping disease (SD), Infectious haematopoietic necrosis (IHN), Koi herpesvirus disease (KHVD), Red sea bream iridoviral disease (RSIVD), Spring viraemia of carp (SVC), and Viral haemorrhagic septicaemia (VHS). At European Union level, Commission Decision 2006/88/EC and Council Implementing Decision 2015/1554/EC provide specific regulation for surveillance and control of listed infectious aquatic diseases in Europe which include the fish viral diseases VHS, IHN, EHN, ISA, and KHVD (European Commission 2006, 2015). Due to the frequent emergence of new serious fish viral diseases, the OIE list of fish viral diseases is regularly being extended. However, apart from these well studied viral diseases, other non-notifiable serious fish viral diseases occur in freshwater fish farming. To focus on these new viral threats for freshwater fish farming, an open workshop was organized at the EAFP Conference at Belfast, 4th September 2017. The workshop consisted of five short lectures and a discussion, involving an audience of 69 international experts, originating from 25 countries, of which 6 outside Europe. The main topics presented included issues related to:i) the difficulty of preventing the global spread of cyprinid herpesvirus 2 (CyHV-2), ii) perhabdoviruses as a threat for percid farming, iii) pathogenesis and diagnostics of piscine orthoreoviruses in farmed rainbow trout, iv) Carp Edema Virus (CEV) in Europe, and v) the potential role of fish endogenous retroviruses in disease emergence. The general aim of the workshop was to identify potential collaborative approaches to carry out multidisciplinary studies aiming to define risks, diagnostic methods and suggest adequate prophylactic measures.