The presence of Viral Haemorrhagic Septicaemia (VHS) has been confirmed at a trout farm in North Yorkshire. VHS is a notifiable disease which affects mainly farmed rainbow trout, and can cause significant fish mortality.

Due to the serious nature of VHS, it is standard policy to place controls on entire river catchments on confirmation of the disease.  Defra has issued an Order under the Diseases of Fish Act 1937, prohibiting movements of fish to and from the catchment of the River Ouse.

Cefas is currently undertaking an epidemiological investigation to determine the source of infection and whether any spread has occurred.  Wild and farmed fish are being sampled within the catchment to determine the extent of spread of the infection. The site has been cleared of fish (which have been sent for disposal at
an approved rendering plant) and the site is now being prepared for disinfection.

Once the disease situation is fully under control certain fish movements may be allowed  to take place in the affected area with the supervision of the Cefas Fish Health Inspectorate.

The UK is currently designated by the EU as an 'Approved Zone' free of VHS which allows safeguards to be placed to minimise the risk of introduction of the disease through trade. This outbreak requires that this status is suspended until it can be redefined to exclude the affected Ouse catchment area. Currently the UK will be unable to trade live fish with VHS free 'Approved Zones' throughout the EU Community.

The live fish movement restriction does not apply to the movement of ornamental fish to or from pet shops and aquaria.

VHS has no implications for human health.  

May 30th 2006: Notifiable disease (VHS) confirmed on a trout farm in Yorkshire

Scientists at the Centre for Environment Fisheries and Aquaculture Science (Cefas) are investigating the origins of an outbreak of a notifiable fish disease at a trout farm.

Movement restriction orders on fish farms along the entire River Ouse catchment area in Yorkshire are in place following confirmation of Viral Haemorrhagic Septicaemia (VHS). In total there are 33 other fish farms facing movement restrictions. These farms include trout farms, hatcheries amd coarse fish farms.

VHS is a notifiable disease affecting mainly farmed rainbow trout which can cause up to 80 per cent mortality.

Fish farms in the area and others which may have had contact with the infected premises have been inspected but none have so far shown clinical evidence of disease. However, results of tests from samples are expected soon (tests can take up to two weeks) and inspections of other sites in the Ouse catchment area are due to be completed later this week.

The affected farm has now been cleared of all fish and plans are in place to disinfect the site.

More info to follow when we have an update...