First report of infectious salmon anemia (ISA) in the United States.

Abstract

The first documented appearance of infectious salmon anaemia (ISA) at a US salmon farm is described. Fish presented clinically with listless behavior, exophthalmia, pale gills, and fin and skin haemorrhages. Gross necropsy findings included dark livers, swollen spleens and petechial haemorrhaging of mesenteric fat and internal organs. Laboratory testing results consisted of cytopathic effect attributable to ISAV on cell culture, appropriately amplified cDNA fragments by rt-PCR, and positive-range immunochemistry results. Histopathology suggestive of ISA was observed in kidney and liver sections.