Isolation of infectious salmon anemia virus (ISAV) from Atlantic salmon in New Brunswick, Canada

Infectious salmon anemia virus (ISAV) was isolated at a marine grow-out site in New Brunswick, Canada, from Atlantic salmon Salmo salar which experienced mortalities due to hemorrhagic kidney syndrome (HKS). Of 20 fish sampled in this study, 14 showed histologically various degrees of interstitial hemorrhaging, tubular epithelial degeneration and necrosis, and tubular casts in the posterior kidney, typical of HKS. Posterior kidney and spleen homogenates produced a cytopathic effect on chinook salmon embryo (CHSE-214) cells 10 to 14 d after inoculation. Pleomorphic virus particles in the size range 80 to 120 nm were seen by electron microscopy. The virus was confirmed as ISAV using reverse transcriptase-polymerase chain reaction (RT-PCR). This is a systematic diagnostic study of the isolation of ISAV on the North American continent and the first description of the growth of ISAV on the CHSE-214 cell line.