SSO DISEASE( HAPLOSPORIDIUM COSTALE )IN CANADA
Information received by OIE on 26 March 2003 from Dr Brian Evans, Executive Director, Canadian Food Inspection Agency, Ottawa:
Report date: 24 March 2003.
Nature of diagnosis: laboratory.
Date of initial detection of animal health incident: early 2003.
Estimated date of first infection: unknown.
Location : southern Gulf of St. Lawrence, province of Nova Scotia (Atlantic coast). No. of outbreaks: 1
Location: northern Cape Breton, province of Nova Scotia (Atlantic coast). No. of outbreaks: 1
Description of affected population: American oysters( Crassostrea virginica ).
Diagnosis: SSO infection was found in samples collected as part of the MSX survey(1).
A. Laboratories where diagnosis was made:
- The presumptive diagnosis was made by the Shellfish Health Unit, Gulf Fisheries Centre (Fisheries and Oceans Canada), Moncton, province of New Brunswick.
- Diagnosis was confirmed by the Virginia Institute of Marine Science, United States of America (OIE Reference Laboratory for MSX and SSO diseases).
B. Diagnostic tests used: histology and PCR(2).
C. Causal agent: Haplosporidium costale .
- No deaths have been associated with these infections, which were were so light that it required PCR confirmation to determine haplosporidian and species identity.
- There is no evidence of proliferation or spore formation to date.
- SSO is not a human health concern.
- This is the first report of this parasite in Canadian American oysters. Cases of abnormal mortality and oysters destined for live transfer between Atlantic provinces are routinely examined histologically by shellfish health pathologists at the Gulf Fisheries Centre laboratory (Fisheries and Oceans Canada) in Moncton, province of New Brunswick. No evidence of SSO has been detected in any of these investigations over the last 15 years.
- Additional samples from Gulf New Brunswick oysters will be checked for both SSO and MSX using PCR and histology.
Control measures: the Federal Department of Fisheries and Oceans and provincial authorities have been notified. SSO identification will not change any of the precautionary controls put in place for MSX disease in the Atlantic Region in November 2002.
(1) see Disease Information , 15 (43), 212, dated 25 October 2002, and 15 (52), 274, dated 27 December 2002
(2) PCR: polymerase chain reaction