Abstract Salmonid alphavirus (SAV), genus Alphavirus , family Togaviridae , is a single-stranded RNA virus affecting Atlantic salmon ( Salmo salar ) and rainbow trout ( Oncorhynchus mykiss ). It is known to be responsible for pancreas disease (PD) and sleeping disease (SD) which are increasing problems, causing high fish mortality and economic losses in the European aquaculture industry. Pancreas disease was first described in Atlantic salmon in Scotland in 1976 and a similar disease caused by the closely related sleeping disease virus was first described in rainbow trout in France. There have also been reports of salmonid alphavirus infections from other European countries, including Ireland, England, Norway, Germany, Italy, and Spain. Salmonid alphaviruses have been classified into six subtypes (SAV1–6). SAV1 and SAV4–6 cause pancreas disease in Atlantic salmon in Ireland or Scotland, SAV2 is the causative agent of sleeping disease in rainbow trout, and SAV3 has been detected in Atlantic salmon in Norway. The aim of this paper was to summarise current knowledge of infections caused by salmonid alphavirus and diagnostic methods including the newest techniques, and to briefly describe prevention from SAV infections by vaccination.
The European eel (Anguilla anguilla) is a catadromous fish with a complicated life cycle. The long-term impact of anthropopressure, environmental pollution and diseases have led to a risk of extinction. The aim of the present study was to determine the influence of Anguillid herpesvirus-1 infection on the innate immunity of European eel from natural conditions. Spleen phagocyte respiratory burst activity and potential killing activity, as well as pronephros lymphocyte proliferation stimulated by concanavalin A or lipopolysaccharide were measured. The analyses of the results showed that all studied parameters were significantly higher (P⟨0.05) in AngHV-1-negative fish compared to the ones where the presence of viral DNA was confirmed.
