Joint Statement - Detection of MSX in Bedeque Bay, Prince Edward Island

July 13, 2024 – Ottawa, Ontario

The Canadian Food Inspection Agency (CFIA) has confirmed the presence of multinucleate sphere unknown (MSX) caused by Haplosporidium nelsoni in wild oyster samples collected in Bedeque Bay, Prince Edward Island (PEI). While MSX prevents oysters from thriving, such as decreased rates of growth and increased oyster mortality, this disease poses no risk to human health, nor does it pose a risk to food safety.

To limit the spread of the disease, the CFIA, Fisheries and Oceans Canada (DFO) and the Province of PEI are working together with stakeholders and provincial/territorial partners to monitor the situation and take action as necessary.

These actions are part of the Government of Canada's One Health approach to prepare for, detect, and manage animal diseases. In addition to existing robust protective measures and increased animal surveillance measures, the CFIA, DFO and the Province continue to conduct tracing activities and testing of oysters to gain insight into the presence of MSX in the area. This testing is not conducted for food safety purposes.

Now that MSX has been detected, together the Government of Canada and Province of PEI are continuing the investigation and taking further response measures. At this time, these include:

• applying movement controls in the Bedeque Bay area;
• further investigating the potential source of the detection;
• engaging scientists, producers and fish harvesters to continue to monitor mollusc health, including advising when significant decreased rates of growth or increased mortalities are observed; and
• ensuring that information regarding detection and movement control information is available to producers.

Quick Facts

• MSX is not a food safety concern.
• Haplosporidium nelsoni causes multinucleate sphere unknown (MSX) in cultured and wild American oysters, specifically Crassostrea virginica.
• Ongoing federal and provincial control and detection measures for MSX span the continuum from monitoring/surveillance and risk assessment, to laboratory capacity, updated guidance and communications, and science coordination.
• In Canada, our animal disease surveillance network is supported by industry, the provinces and the federal government through a series of laboratories. There are measures in place for sampling and testing when there is any suspicion of animal disease.
• Canada's National Aquatic Animal Health Program (NAAHP), co-delivered by the Canadian Food Inspection Agency (CFIA) and Fisheries and Oceans Canada (DFO), is responsible for preventing the introduction and/or spread of significant aquatic animal diseases of finfish, molluscs and crustaceans.

Related links

• Haplosporidium nelsoni (MSX)
• National Aquatic Animal Health Program
• Government of Prince Edward Island – Fisheries, Tourism, Sport and Culture