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Viral haemorrhagic septicemia (VHS) / Infectious Haematopoetic Necrosis (IHN)

VHS and IHN are two viral disaeases  that might cause large losses in farmed and wild fish populations. Norway has status as free of these diseases.

The aim of the programme is to document the absence of VHS virus and IHN virus in fish farms in order to maintain Norway’s free status.

Norway obtained disease free status for VHS and IHN in 1994. VHS was diagnosed in farmed rainbow trout in Norway in 2007 and disease free status was temporarily suspended. Measures to eliminate the disease and prevent its spread were immediately taken by the Norwegian Food Safety Authority. In 2011 Norway regained its VHS free status.

Now the strategy for the surveillance programme is risk-based, i.e. targeting fish with disease signs. The programme include active seawater sites with rainbow trout and Atlantic salmon.