Infectious haematopoietic necrosis (IHN)
How to spot Infectious haematopoietic necrosis (IHN), what to do if you suspect it and measures to prevent its spread.
Applies to England and Wales
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Details
颁辞苍迟别苍迟蝉听
- How to spot IHN
- How IHN is spread
- Preventing and controlling IHN
- Further information on IHN
- Legislation relating to IHN
- Who to contact if you suspect IHN
Infectious haematopoietic necrosis (IHN) is a viral disease predominantly affecting salmonid species. Outbreaks are most severe in fingerlings and juvenile fish. Serious outbreaks can result in losses of 95% or more. IHN may be carried by a range of freshwater and marine species of fish. More information on susceptible and vector species can be found here: Susceptible and vector species - 188体育 (www.gov.uk)
Great Britain (GB) is free from IHN and it is a 鈥�listed鈥� (also referred to as 鈥榥otifiable鈥�) disease which you are legally obligated to [report immediately to the Fish Health Inspectorate (FHI)], Cefas.听
Historically IHN was only found in parts of North America. However, the disease has since spread to Europe and Asia through movement of infected fish and eggs. IHN has never been detected in GB.听
It does not affect humans.听
How to spot IHN
IHN typically occurs in water temperatures between 8掳C and 15掳.听
Fish can appear lethargic with moments of frenzied and erratic swimming.听听
Signs of the disease can include:听
- Behavioural changes such as lethargy mixed with frenzied, abnormal activity including spiral swimming听
- Trailing faecal casts听
- Pale gills听
- Darkening of the skin听
- Swollen abdomen听
- Bulging eyes听
- Areas of pinprick like bleeding e.g. at base of fins, around the head, and vent听
How IHN is spread听
IHN can be spread through movements of infected fish, contaminated water, and contaminated equipment such as husbandry, angling and fish transport equipment and boats.听听
Infected fish do not have to be sick or diseased to spread the virus.听
Preventing and controlling IHN听
There is no treatment for IHN.听听
Prevention is the best approach to controlling the disease. You can protect your fish by being aware of the signs of IHN and other serious diseases and checking stock health regularly.鈥� Implement good husbandry and biosecurity practises, including surface disinfection of newly fertilised and eyed salmonid eggs using an appropriate method. Further information on biosecurity measures plans, guidance and templates can be found here: Biosecurity Measure Plans - Information and Templates - 188体育 (www.gov.uk)鈥�
You must be sure any fish introduced are IHN free. Do not buy fish of unknown origin. Follow the rules on moving aquatic animals: Aquatic animal health and movements guides - 188体育 (www.gov.uk)听
You must report it to the FHI immediately if you notice or become aware of fish showing any of the signs of IHN. The FHI will investigate and apply disease control measures if required.听
Further information on IHN听
IHN.听
Legislation relating to IHN听
2009听听
The listed diseases are in and 听
Who to contact if you suspect IHN听
If you suspect or know of a listed disease of fish and shellfish in England and Wales, you must report it immediately to the Fish Health Inspectorate (FHI), Cefas. You must also tell the FHI immediately if you know or suspect that increased mortality has occurred.听听
Under the Aquatic Animal Health (England and Wales) Regulations 2009 it is a legal obligation to report suspicion of IHN in any farmed or wild fish to the FHI. It is an offence under the Regulations to fail to inform the FHI of suspicion of IHN.听
- 贰尘补颈濒:鈥�[email protected]听
- Telephone: 01305 206700听- Monday to Thursday - 9:00 am to 5:00 pm, Friday 9:00 am to 4:30 pm听
- For emergencies out of hours telephone: 01305 206630听
Fish Health Inspectorate听听
Centre for Environment, Fisheries and Aquaculture Science (Cefas)听
Barrack Road听The Nothe
Weymouth
Dorset
DT4 8UB