The Icelandic Food and Veterinary Authority (MAST) has found evidence of infectious salmon anaemia (ISA) in an open-net salmon farm in Reyðarfjörður fjord, East Iceland. ISA is a highly infectious viral disease that has no treatment and causes high mortality in farmed Atlantic salmon. This is the first time the virus has been diagnosed in Icelandic waters.
The virus has been diagnosed in a salmon farm owned by Laxar fiskeldi ehf. Follow-up tests are now being conducted to confirm the diagnosis. A decision has been made to slaughter all of the fish in the pen where the virus was detected. Fish in the farm’s other pens appear to be healthy, according to the notice from MAST. It will, however, be closely monitored in the near future.
The ISA virus is harmless to humans and is not transmitted through fish products. It is also known as “salmon flu,” and belongs to the Orthomyxoviridae family of influenza viruses and has most of the characteristics of influenza viruses known in mammals and birds. A benign variant of the virus is widespread and “probably found everywhere in salmons’ environment,” according to the notice from MAST. The pathogenic ISA virus, like the one that has now been detected in Iceland for the first time, is created by mutation of the benign variant.
The first case of ISA was detected in Norway in 1984. Since then it has been detected in many other salmon farming nations, including Canada (1996), Scotland (1998), the Faroe Islands (2000), the USA (2001), Chile (2001), and Ireland (2002).
“The diagnosis of the virus emphasises the importance of monitoring and infection control in order to maintain good disease status in Iceland and prevent diseases such as ISA emerge and get a foothold in salmon farms,” the MAST statement concludes.