First confirmation of salmonid alphavirus infection in rainbow trout in Bosnia and Herzegovina and Serbia

Sleeping disease is a highly infectious viral disease caused by salmonid alphavirus subtype 2 (SAV2 FW), affecting mainly rainbow trout Oncorhynchus mykiss farmed in freshwater. During March to May 2014, disease episodes with clinical signs of sleeping disease in rainbow trout fingerlings occurred almost simultaneously in 2 trout farms located in Bosnia and Herzegovina (BiH) and Serbia. The infection of rainbow trout with SAV2 FW in 2 farms was confirmed by virus isolation and molecular methods. This is the first isolation and molecular characterization of SAV2 FW in BiH and Serbia.

First confirmation of salmonid alphavirus infection in Arctic char Salvelinus alpinus and in Austria

To date, sleeping disease (SD) caused by salmonid alphavirus 2 (SAV 2) has been reported in freshwater rainbow trout Oncorhynchus mykiss and Atlantic salmon Salmo salar. This study describes for the first time the occurrence of SD in farm-reared Arctic char Salvelinus alpinus and the occurrence of SAV in Austria. Clinical symptoms were indicative of the disease, and the diagnosis was confirmed by histopathology, infectivity in first passages of CHSE-214 cells and PCR. The phylogenetic analysis of the amplified SAV-nonstructural protein-3 (nsP3) fragment revealed the affiliation to the SAV 2 genotype.