Information Document with Request for Input and Scientific Data: Vibrio parahaemolyticus in oyster shellstock intended for raw consumption

March 2019

I. Context

Health Canada's Food Directorate is in the process of reviewing its current Vibrio parahaemolyticus (Vp) microbiological criteria pertaining to oysters intended for raw consumption in order to protect the health of Canadians. To facilitate this work, Health Canada is issuing a call for data to identify the risk factors that may have an impact on the increased risk of Vp presence and to identify potential mitigation options/strategies specific to the production, distribution and consumption of such products.

II. Background

Vp is a naturally occurring organism that can be isolated from coastal waters. This bacterium thrives in warm temperatures. Because of the physiological nature of oysters, they will concentrate Vp as they filter-feed. Furthermore, if oysters are not maintained under strict temperature control by the various stakeholders along the food chain (i.e., harvesters, processors, distributors, retailers/restaurants and consumers), Vp would have the potential to further spread and rapidly grow to unacceptable levels, if already present in oysters. This being said, during the warm summer months, in certain circumstances, the levels of Vp at harvest may be high enough to cause illnesses; even if abusive temperatures did not occur subsequently.

In the summer of 2015, oysters harvested from BC coastal waters intended for raw consumption were implicated in a Canadian Vp outbreak (i.e., 82 laboratory confirmed cases). Two additional Canadian Vp outbreaks associated with the consumption of raw oysters have occurred back in 1997 and in 2006. This situation is not unique to Canada as many Vp outbreaks have also been reported worldwide.

Current Health Canada microbiolgical criteria to address Vp safety issues associated with the consumption of raw oysters is outlined in the "Health Products and Food Branch (HPFB) Standards and Guidelines for Microbiological Safety of Food - An Interpretive Summary". A review of these microbiological criteria to assist in the management of the potential health risk associated with raw oyster's consumption is necessary and it should take into consideration Canadian specific practices at different levels along the food continuum, as well as data on Vp prevalence and concentration at different points relevant to the Canadian context.

III. Request for Scientific Data and Information

In support of the review of the current Health Canada microbiological criteria to address Vp safety issues associated with the consumption of raw oysters, Health Canada is issuing a call for data (for seasons 2016, 2017 and 2018). Information of interest for this request includes, but is not limited to:

Production and processing-related information as well as Vp microbiological testing results from any stage in the harvesting, production and distribution chain (i.e., routine monitoring, verification, regulatory and/or exceptional testing data). The following serves as a guide for the broad type of information which is of interest to Health Canada.

  1. Harvesters:
    • Quantity of oysters harvested by month (please, specify for each month)? Proportion intended for direct raw consumption by month (please, specify for each month)?
    • Fisheries and Oceans Canada's statistical areas (and sub-areas) for harvesting?
    • Type of harvesting (e.g., intertidal, beach, deep water) with specificities
    • Protocol for harvesting (e.g., flowchart of harvesting sequence) and equipment used?
    • Method for rapid cooling?
    • Sanitation practices (including protocol, product used, frequency, etc.)?
    • In the warm summer months, do you implement specific harvesting practices to reduce/eliminate the risk associated with Vp? If so, what are they?
    • Given that "harvest" begins at the time the first oyster is exposed to the air (i.e., emerged):
      • How long (average and maximum) does it take to place the entire harvest of oysters under temperature control?
      • What is the target temperature (for temperature control)?
      • How is temperature control performed (i.e., the chilling methods implemented)?
      • How is temperature control ensured? Which measurement checks are you taking? Frequency of testing?
    • Will/Could you implement additional specific interventions to control the potential spread and growth of Vp? If so, please specify.
    • Microbiological enumeration of Vp on raw oysters at the harvesting level.
      • Please specify the microbiological method used, if known.
      • Frequency of testing?
      • How/where are the oysters sampled?
      • Please share these Vp microbiological testing results (e.g., via an attached Excel spreadsheet - monthly report)
      • Is this information shared with your buyers or other stakeholders?
    • Are you performing other relevant microbiological tests (Vp or others) on raw oysters and/or its environment (e.g., water)? If so, please name them.
    • What is your source of information on mitigation strategies to minimize the risk associated with Vp (e.g., Web, workshops, etc.)?
    • Do you educate your buyers or others along the food chain about the importance of keeping and handling oysters under temperature control at all times? If so, how?
  2. Processors:
    • Quantity of oysters received by month (please, specify for each month)? Proportion intended for direct raw consumption by month (please, specify for each month)?
    • Number of harvesters you get your oysters supplies from and their harvesting areas (sub-areas)?
    • Protocol for processing (e.g., flowchart of processing sequence, including relay/depuration, etc.) and equipment used?
    • What are the average and maximum time for processing oysters?
    • Sanitation practices (including protocol, product used, frequency, etc.)?
    • Do you implement specific processing practices to reduce/eliminate the risk associated with Vp? If so, what are they?
      • How do you verify that the oysters you received were kept under temperature control during and after harvest?
      • What is the target temperature (for temperature control)?
      • How do you ensure that oysters you had processed are kept under temperature control?
        • How is temperature control performed (i.e., chilling methods implemented)?
        • Which measurements are you taking?
        • Frequency of testing?
    • Will/Could you implement additional specific interventions to control the potential spread and growth of Vp? If so, please specify
    • Microbiological enumeration of Vp on raw oysters upon reception at the processor level.
      • Please specify the microbiological method used, if known.
      • Frequency of testing?
      • How/where are the oysters sampled?
      • Please share these Vp microbiological testing results (e.g., via an attached Excel spreadsheet - monthly report)
      • Is this information share with your suppliers or other stakeholders?
    • Microbiological enumeration of Vp on raw oysters post-processing, at the processor level.
      • Please specify the microbiological method used, if known.
      • Frequency of testing?
      • How/where are the oysters sampled?
      • Please share these Vp microbiological testing results (e.g., via an attached Excel spreadsheet - monthly report)
      • Is this information shared with your buyers or other stakeholders?
    • Are you performing other relevant microbiological tests (Vp or others) on raw oysters and/or its environment (e.g., processing environmental surfaces, etc.)? If so, please name them.
    • What is your source of information on mitigation strategies to minimize the risk associated with Vp (e.g., Web, workshops, etc.)?
    • Do you educate your buyers and others along the food chain about the importance of keeping and handling oysters under temperature control at all times? If so, how?
  3. Distributors:
    • Quantity of oysters being distributed to retailers, to restaurants, directly to consumers and others (as applicable) by month (please, specify for each month)? Proportion of these oysters intended for direct raw consumption by month (please, specify for each month)? Average number of clients or proportion going to each?
    • Description of the distribution chain
    • Type of storage (e.g., wet storage vs. dry storage) and equipment used?
    • Sanitation practices (including protocol, product used, frequency, etc.)?
    • Do you ensure that oysters that you received have been kept under temperature control?
      • What is the target temperature (for temperature control)?
    • How do you ensure that oysters that you handle are being kept under temperature control?
      • How is temperature control performed (i.e., chilling methods implemented)?
      • Do you track temperature of oysters during storage? If so, how (e.g., which measurements are you taking? Frequency of testing? What are the average and maximum storage time?)?
      • Do you track temperature of oysters during transportation? If so, how (e.g., which measurements are you taking? Frequency of testing? What are the average and maximum transportation time?)?
    • Will/Could you implement additional specific interventions to control the potential spread and growth of Vp? If so, please specify.
    • Microbiological enumeration of Vp on raw oysters at the distribution level.
      • Please specify the microbiological method used, if known.
      • Frequency of testing?
      • How/where are the oysters sampled?
      • Please share these Vp microbiological testing results (e.g., via an attached Excel spreadsheet - monthly report)
      • Is this information shared with your buyers or other stakeholders?
    • Are you performing other relevant microbiological tests (Vp or others) on raw oysters and/or its environment (e.g., environmental surfaces, etc.)? If so, please name them.
    • What is your source of information on mitigation strategies to minimize the risk associated with Vp (e.g., Web, workshops, etc.)?
    • Do you educate your buyers or others along the food chain about the importance of keeping and handling oysters under temperature control at all times? If so, how?
  4. Retailers:
    • Quantity of oysters received by month (please, specify for each month)? Proportion of these oysters intended for direct raw consumption by month (please, specify for each month)?
    • Data relating to storage conditions (e.g., time-temperature)
    • Type of storage and type of display (e.g., wet vs. dry) and equipment used?
    • Sanitation practices (including protocol, product used, frequency, etc.)?
    • Do you ensure that oysters that you received have been kept under temperature control?
      • What is the target temperature (for temperature control)?
    • How do you ensure that oysters that you handle are being kept under temperature control?
      • How is temperature control performed (i.e., chilling methods implemented)?
      • Do you track temperature of oysters during storage? If so, how (e.g., which measurements are you taking? Frequency of testing? What are the average and maximum storage time?)?
      • Do you track temperature of oysters during display? If so, how (e.g., which measurements are you taking? Frequency of testing? What are the average and maximum display time?)?
    • Will/Could you implement additional specific interventions to control the potential spread and growth of Vp? If so, please specify.
    • Microbiological enumeration of Vp on raw oysters at the retail level.
      • Please specify the microbiological method used, if known.
      • Frequency of testing?
      • How/where are the oysters sampled?
      • Please share these Vp microbiological testing results (e.g., via an attached Excel spreadsheet - monthly report)
      • Is this information shared with any stakeholders?
    • Are you performing other relevant microbiological tests (Vp or others) on raw oysters and/or its environment (e.g., retail environmental surfaces, etc.)? If so, please name them
    • What is your source of information on mitigation strategies to minimize the risk associated with Vp (e.g., Web, workshops, etc.)?
    • Do you educate staff and others (e.g., consumers) along the food chain about the importance of keeping and handling oysters under temperature control at all times? If so, how?
    • If selling shucked oysters, do you inform buyers that those should be cooked? If so, how?
  5. Restaurants:
    • Quantity of oysters received by month (please, specify for each month)? Proportion of these oysters intended for direct raw consumption by month (please, specify for each month)?
    • Type of storage (e.g., wet vs. dry) and equipment used?
    • Data relating to storage conditions (e.g., time-temperature), method of preparation, consumption pattern or other extrinsic factors that may have an impact on survival and growth of Vp in raw oysters intended for raw consumption.
    • Sanitation practices (including protocol, product used, frequency, etc.)?
    • Do you ensure that oysters that you received have been kept under temperature control?
      • What is the target temperature (for temperature control)?
    • How do you ensure that oysters that you handle are being kept under temperature control?
      • How is temperature control performed (i.e., chilling methods implemented)?
      • Do you track temperature of oysters during storage? If so, how (e.g., which measurements are you taking? Frequency of testing? What are the average and maximum storage time?)?
      • Do you track temperature of oysters during service? If so, how (e.g., which measurements are you taking? Frequency of testing? What are the average and maximum time for serving?)?
    • Will/Could you implement additional specific interventions to control the potential spread and growth of Vp? If so, please specify.
    • Microbiological enumeration of Vp on raw oysters at the restaurant level.
      • Please specify the microbiological method used, if known.
      • Frequency of testing?
      • How/where are the oysters sampled?
      • Please share these Vp microbiological testing results (e.g., via an attached Excel spreadsheet - monthly report)
      • Is this information shared with any stakeholders?
    • Are you performing other relevant microbiological tests (Vp or others) on raw oysters and/or its environment (e.g., environmental surfaces, etc.)? If so, please name them.
    • What is your source of information on mitigation strategies to minimize the risk associated with Vp (e.g., Web, workshops, etc.)?
    • Do you educate staff and others along the food chain about the importance of keeping and handling oysters under temperature control at all times? If so, how?
    • If buying shucked oysters, do you always cook them for your customers? If so, how?
  6. Consumers:
    • Data relating to preparation practices and storage conditions (e.g., time-temperature) at consumer homes, i.e., storage, method of preparation, consumption pattern).

IV. Information and Data

Information and data may be submitted in writing either by regular mail or electronically (preferably) at the address indicated below. If you are submitting information or data electronically, please use the words "Raw Oysters Data and Information" in the subject box of your e-mail.

This call for data will close at 12:00 am EST on April 17th, 2019.

Mailing address:

Health Canada, Bureau of Microbial Hazards
Evaluation Division
251 Sir Frederick Banting Driveway, Postal Locator: 2204E
Ottawa, Ontario
K1A OL2

E-mail address: hc.bmh-bdm.sc@canada.ca

Confidential and/or unpublished information

Health Canada recognizes that some of the available information and/or relevant data that is being requested may be unpublished or of a confidential nature. If submitted, unpublished information would remain the property of the submitting organization or individual and its confidentiality will be safeguarded in so far as it is possible to do so within current regulations governing such issues. Specific issues relating to confidentiality should be discussed directly between the information owners and Health Canada. For these and other issues please contact the Bureau of Microbial Hazards through the contact information provided above.

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