The outbreak occurred in a susceptible population of 23000 Atlantic salmon.
There were 1060 deaths out of 1100 cases of the disease. The other 40 infected animals were destroyed as a preventative measure.
From an epidemiological point of view, the Norwegian Food Safety Authority considers the ISA outbreak at Nystølvågen-24495 to be a first occurrence within this ISA free area.
They said that based on the genotyping of the complete ISA virus segment 6, it seems to be an isolated outbreak.
The outbreak, in a semi-open production system, occurred in the Hordaland county of Norway.