Viral haemorrhagic septicemia and infectious hematopoietic necrosis

Updated 05.01.2023

Viral haemorrhagic septicemia (VHS) and infectious hematopoietic necrosis (IHN) are virus diseases causing heavy losses in salmonids. Norway currently has a free status for both diseases.

Both diseases are due to infection with Novirhabdovirus and are listed nationally and internationally. The VHS virus is also detected in several marine species including lumpfish and wrasse.

The purpose of the surveillance program is to document the free status for VHS and IHN in salmon and rainbow trout in Norway.

Background

Since 1994, Norway has had a free status for VHS and IHN, which we achieved on the basis of analyzes carried out at the Veterinary Institute since 1967. The surveillance program started in 2004. In 2007, VHS was detected in farmed rainbow trout, and measures to prevent spread and eradicate the disease were implemented. IHN has never been detected in Norway, and in 2011 we got back the free status for VHS.

Today, the surveillance program is risk-based and includes active sites with salmon and rainbow trout. This means that relevant samples submitted to the Veterinary Institute with suspicion of listed disease or for general disease investigation are examined for VHSV and IHN. Samples from lumpfish and wrasse are also examined, and samples from wild pink salmon or humpback salmon will be included in the surveillance program in 2019.

2021

This surveillance programme has a risk-based approach. The core surveillance activity is the routine clinical inspections on marine sites with farmed salmonids and analyses of samples collected from diseased fish. In 2021, samples from pink salmon caught in several rivers as well as rainbow trout and brown trout from freshwater sites were also included. Viral haemorrhagic septicaemia virus and infectious haematopoietic necrosis virus were not detected in any of the samples tested in the 2021.

Download report

VHS and IHN in fish 2021 (pdf 1mb)

Previous reports

VHS and IHN in fish 2020 (pdf 967kb)
VHS and IHN in fish 2019 (pdf 1mb)
VHS and IHN in fish 2018 (pdf 1mb)
VHS and IHN in fish 2017 (pdf 1mb)
VHS and IHN in fish 2016 (pdf 1mb)
VHS and IHN in fish 2015 (pdf 1mb)
VHS and IHN in fish 2014 (pdf 757kb)
VHS and IHN in fish 2012 (pdf 2mb)
VHS and IHN in fish 2011 (pdf 1mb)
VHS and IHN in fish 2010 (pdf 605kb)
VHS and IHN in fish 2009 (pdf 544kb)
VHS and IHN in fish 2008 (pdf 660kb)
VHS and IHN in fish 2007 (p. 135) (pdf 6mb)
VHS and IHN in fish 2006 (p. 133) (pdf 3mb)
VHS and IHN in fish 2005 (p. 125) (pdf 4mb)
VHS and IHN in fish 2004 (p. 127) (pdf 4mb)
VHS and IHN in fish 2003 (p. 125) (pdf 6mb)