Disease monitoring and investigation

The health status of Britain's freshwater fish stocks has been legally protected since 1937 when the Diseases of Fish Act was introduced. As a consequence our fish health status has remained very high, and under the new European Fish Health regime we maintain a status higher than many other European states.

The Fish Health Inspectorate (FHI) is charged with implementing the Fish Health regime in England and Wales on behalf of Defra and NAWAD. The Inspectorate's duties include:

• Monitoring for notifiable diseases or other serious diseases.
• Investigating suspected cases of notifiable disease or abnormal mortalities.
• The placing of statutory controls.

Monitoring for notifiable diseases or other serious diseases

In order to maintain the GB Approved Zone status, the Fish Health Inspectorate is required to undertake an annual national health monitoring programme. This includes visits to all registered fish and shellfish farms to inspect stocks and take samples for testing where there is evidence of disease and routinely on a bi-annual basis as required under EU Legislation.

There are eight notifiable diseases of fish and six of shellfish, all of which fall into three categories. These are:

List I Diseases

Diseases exotic to the EU at the time of listing which pose a serious economic threat to aquaculture and for which treatment or vaccination is not available. The EU regime requires Member States to take immediate action to eradicate the disease should outbreaks occur. Includes:

• Infectious Salmon Anaemia (ISA)

List II Diseases

Diseases which are established in parts of the EU and pose a serious economic threat to aquaculture and for which treatment or vaccination is not available. The EU is zoned by water catchment areas into Approved Zones and Farms (free of the disease(s)) and the areas that are not approved. Movements into Approved Zones or Farms can only take place from those areas of equivalent or higher health status. The regime also provides for Member States to take action to eradicate these diseases in order to establish Approved Zones and Farms. Includes:

• Fish Diseases:
  • Viral Haemorrhagic Septicaemia (VHS)
  • Infectious Haematopoietic Necrosis(IHN)
• Shellfish Diseases:
  • Bonamiosis
  • Marteiliosis
  • Iridovirosis
  • Mikrocytosis
  • Haplosploridiosis
  • Perkinosis

List III Diseases

Diseases which are a serious problem in some Member States and for which treatment or vaccination is not available or possible. With EU agreement national programmes can be established to contain or prevent the introduction of these diseases. List III Diseases, for which the UK have applied controls for, include:

• Spring Viraemia of Carp (SVC)
• Gyrodactylosis (caused by G. Salaris)
• Bacterial Kidney Disease (BKD)
• Furunculosis in Salmon (FRC)
• Infectious Pancreatic Necrosis (IPN) in salmon

Of these diseases, ISA, IHN, VHS and Gyrodactylosis have never been found in England and Wales. For more details on the above diseases, including abstracts from scientific literature, register with us now on the eFishBusiness website.

If you suspect the presence of any of the above notifiable diseases you must notify us immediately. You can contact us by phone or in writing.

Investigating suspected cases of notifiable disease or abnormal mortalities

Farmers must notify us immediately if they suspect the presence of any notifiable disease or are experiencing abnormal mortalities.

Following notification, we will visit the site, as soon as possible, to inspect stocks and obtain samples for analysis where necessary. Where we suspect a notifiable disease we  may impose temporary movement controls (as a precaution).

Where a notifiable disease is confirmed on a site we will instigate a programme of contact chasing at other farms which have supplied or been supplied by it. Inspection and sampling will take place on each site having such contact with the diseased site within the previous 12 months.

Investigations into serious disease outbreaks also enables us to identify new and emerging diseases which may affect  farmed or wild fish stocks.

Diagnosing the cause of disease outbreaks or abnormal mortalities.

The Cefas Weymouth laboratory is designated as a national Reference Laboratory under the EU Fish Health regime and has modern diagnostic facilities. Routine samples taken by the Inspectorate are screened for serious fish pathogens, using methods laid down by the EU Fish Health regime. The laboratory also has experts in molecular biology, virology, bacteriology, parasitology and histopathology working in multidisciplinary teams applying the latest techniques, to assist in the identification of the cause of disease outbreaks.