Oyster Herpesvirus (OsHV-1 µvar) Outbreak Confirmed

Information Bulletin ref: CD 04 / 2010
Date: Tuesday 20th July 2010.

On 13th July Fish Health Inspectors from the Centre for Environment, Fisheries and Aquaculture Science (Cefas) inspected a shellfish farm in Whitstable, Kent following reports of high levels of mortality in Pacific (rock) oysters Crassostrea gigas. Samples taken from the affected site were confirmed as positive for oyster herpesvirus (OsHV-1 µvar), and a Containment Area has been declared in The Swale, Thames and North Kent Coast, outlined in the attached map.

In accordance with Commission Regulation 175/2010, movements of shellfish out of the Containment Area in The Swale, Thames and North Kent Coast, have been restricted, following the confirmation of oyster herpes virus (OsHV-1 µvar).

Cefas acting on behalf of Defra has issued a confirmed designation prohibiting the movement of Pacific oysters from the Containment Area and applying the following additional control measures:

• You must apply to the Fish Health Inspectorate for permission if you wish to move any Pacific oysters out of the area, including movements into purification centres (depuration plants).
• You must notify the Fish Health Inspectorate of any increased or unexpected mortality observed in shellfish stocks.
• Confirmed Designation number CD Area 03 issued on 27th March 2009 for the control of Bonamiasis in Ostrea edulis (native oysters) remains unaffected by this notice.

OsHV-1 µvar affects Pacific oysters and can result in high rates of shellfish mortalities.

OsHV-1 µvar is an emerging disease that has been associated with high levels of mortality in Pacific oysters in France, Jersey and some bays in the Republic of Ireland.

There are no implications for human health.

Any suspicion of the presence of OsHV-1 in Pacific oysters should be immediately reported to:

The Fish Health Inspectorate, Centre for Environment, Fisheries and Aquaculture Science (Cefas).
Tel: 01305 206700
E-mail: fhi@cefas.co.uk

Notes to editors:

• CD 04/2010, issued under the Aquatic Animal Health, England and Wales Regulations 2009 restricts the movement of any Pacific oysters from within the Containment Area without the prior written consent of the Fish Health Inspectorate at Cefas.
• The designated area is oyster herpesvirus containment area, compartment 6 - Swale, Thames and North Kent Coast
• Clinical signs of the disease may include high levels of mortality particularly affecting juvenile stages of Pacific oysters. These signs usually appear when water temperatures exceed 160C.
• Further information is available at www.efishbusiness.co.uk, or from Cefas, Fish Health Inspectorate, The Nothe, Barrack Road, Weymouth, Dorset, DT4 8UB. Tel: 01305 206700 or e-mail: fhi@cefas.co.uk

Press contact:
Anne McClarnon: 01502 524370 / anne.mcclarnon@cefas.co.uk