Ottawa, July 20, 2024 – The Canadian Food Inspection Agency (CFIA) confirmed the presence of Haplosporidium nelsoni (also known as multinucleate sphere unknown (MSX) in American oysters (Crassostrea virginica) collected in Bedeque Bay, Prince Edward Island on July 11, 2024. This is the first case of MSX in Prince Edward Island (PEI).
A PCZ is a defined area where the disease has been detected or is suspected to exist. The movement of any designated animals (in this case, bivalve shellfish) and things capable of being affected or contaminated by the disease can only be removed, moved in, or taken into that area with a permit issued by the CFIA. Permitting for the movement of oysters and other bivalves within or out of the PCZ direct for human consumption or retail are being prioritized. Additional information on PCZ and applicable control measures, including contact numbers for permit issuance, is available at: Response to MSX and Dermo in oysters.
MSX has previously been identified in American oysters in certain areas of Cape Breton Island, N.S. and in Pacific cupped oyster (Crassostrea gigas) in the Pacific Ocean adjacent to British Columbia (Reportable Mollusc Diseases and Declarations by Province and Marine Area).
Collection, sampling and testing of oysters from other water bodies in PEI is ongoing. The federal and provincial governments continue to work together to develop appropriate response plans, as additional information about the disease situation and impacted areas are received.
All confirmed cases of federally reportable aquatic animal diseases are published on the CFIA website: Confirmed cases of federally reportable aquatic animal diseases in Canada.
Preventing the Spread of MSX
The CFIA's goals are to prevent the spread of MSX through controlling certain movements that pose a risk of spreading the disease. The life cycle of the parasite is not known, but biosecurity measures and monitoring for signs of disease on your farm or lease site, and other activities, can help limit the impacts of disease-causing agents.
- CFIA fact sheet contains additional information about MSX