BONAMIA OSTREAE IN CANADA: Additional information
See also: 10 December 2004
Emergency report (contd) - See Disease Information , 17 (50), 376, dated 10 December 2004
Information received on 15 December 2004 from Dr Brian Evans, Executive Director, Canadian Food Inspection Agency, Ottawa:
Date of the report: 14 December 2004.
The parasite detection is unassociated with a disease outbreak. Deaths of 3- to 4-year-old oysters over the past two years at the site were associated with severe algal bloom; thus, the exact correlation between these deaths and Bonamia ostreae infestation is not clear.
Description of affected population: European flat oysters( Ostrea edulis ).
Location of the affected population: Malaspina Inlet, on the west coast of mainland British Columbia, north-west of Vancouver. European oysters on the Atlantic coast remain free of Bonamia ostreae .
The Fisheries and Oceans Canada Shellfish Health Laboratory in Nanaimo, British Columbia, observed microcells in tissue samples from European flat oysters during a research experiment.
Confirmation was based on analysis of PCR(1) assays, gene sequencing and restriction digest (RFLP) results by the OIE Reference Laboratory for bonamiosis.
A. Source of agent / origin of infestation: the source of the infestation is unknown. Historical histological material of European oysters from British Columbia is being examined at the Shellfish Health Laboratory in Nanaimo.
B. Other epidemiological details:
- The total production of European oysters accounts for less than 1% of British Columbia's oyster production.
- There are no transfers of live oysters between the Pacific and Atlantic coasts of Canada.
Plans to control the disease will be formulated when the extent of infestation in the few British Columbia sites growing European oysters has been determined.
No transfers of live oysters from the affected site occur, except for direct human consumption.
Industry and provincial authorities have been informed and are assisting in the surveillance programme.
(1) PCR: polymerase chain reaction