Aquabirnavirus of European Eel and Rainbow trout

Abstract

In general, viruses are a threat for fish culture and may cause a decline in fish stocks. Some of these viruses may be responsible for the decreasing production in the fish farming industry. This report focuses on aquabirnavirus occurring in the European eel (Anguilla anguilla), the rainbow trout (Oncorhynchus mykiss) and the brook trout (Salvelinus fontinalis). Viruses of the genus aquabirnavirus belong to the family of the Birnaviridae. These viruses are non-enveloped viruses and the genome of the aquabirnavirus contains bi-segmented, double standed RNA. Since 1970 the population of wild eel decreased based on scientific evidence and data from the commercial fishery. In sensitive eel from older age aquabirnavirus may cause mortality up to 100%, especially when these fish are exposed to a stress factor. In rainbow- and brook trout the fry are more sensitive for aquabirnavirus. The diagnostic tests used to diagnose aquabirnavirus in fish are the indirect immunofluorescence test (iIFT), the indirect immunoperoxidase monolayer assay (iIPMA) and the real time polymerase chain reaction (PCR). The aim of this study is to improve the diagnostic possibilities of the detection of aquabirnaviruses from fish.