Bonamia ostrea in the United Kingdom/Great Britain (Wales)

OIE Disease Information (on-line)

Immediate notification report
Information received on 20 May 2006 from Dr Debby Reynolds, Director General for Animal Health and Welfare, Department for Environment, Food and Rural Affairs (DEFRA), London:

Report date:
19 May 2006.

Reason for immediate notification:
re-occurrence of a listed infection in a country, zone/compartment following a report declaring the outbreak(s) ended.

Bonamia ostreae
has been detected in a harvested natural bed of flat oysters( Ostrea edulis )in the River Cleddau in south west Wales.

Bonamia ostreae
was suspected in one oyster, following examination by histological techniques of a routine sample of 30 Ostrea edulis collected in late March from Burton Beach (site A). Two further samples of 150 oysters (from site A) and 16 oysters from Hazelbeach, (site B) were collected in late April and have been processed. Two oysters from site A were found to be positive for Bonamia ostreae by heart smears and histology. Sections were also examined by electron microscope and samples of tissue analysed by molecular biology techniques. Confirmation of identification of the Bonamia ostreae parasite has been made by PCR(1).

Source of agent / origin of infection:
unknown or inconclusive. Under investigation .

Control measures:

- Action has been taken to contain all sources of infection. These measures include prohibiting the movements of molluscs out of the site for relaying or re-immersion in another farm or in the aquatic environment.
- To afford maximum guarantees for the prevention of spread of disease, a temporary control zone has been established based on the tidal excursion model. A surveillance zone of overlapping tidal excursion zones has also been established.
- No movements of live molluscs for relaying have taken place to other Member States or non-European Union countries in recent months from this area.

Final report:
(1) PCR: polymerase chain reaction