Information Document and Request for Scientific Data: Cyclospora cayetanensis on Fresh Leafy Vegetables in Canada

June 2016

I. Context

Health Canada’s Food Directorate has begun development of a risk profile on Cyclospora cayetanensis on fresh leafy vegetables. This is being done to identify the risk factors for contamination associated with critical steps in the production and handling of fresh leafy vegetables, as well as the survival of C. cayetanensis on these commodities. The risk profile will also address potential detection and mitigation options for the control of C. cayetanensison fresh leafy vegetables. To facilitate this work, Health Canada is issuing a call for data to inform the risk profile and to identify potential mitigation strategies that could be applied at various production stages.

II. Background

Illness outbreaks due to the consumption of fresh leafy vegetables contaminated with Cyclospora oocysts have been reported with increased frequency in North America. Since 2000, there have been 8 Canadian and 9 U.S. illness outbreaks linked to C. cayetanensis on fresh leafy vegetables, including a large scale outbreak in the U.S. with 546 cases of illness associated with the consumption of cilantro in 2015.

In all years of leafy green sampling (2009, 2010 and 2013), the Public Health Agency of Canada (PHAC) detected 11 Cyclospora positive samples on leafy greens, 8 of which were C. cayetanensis; including six mixed greens, and two spinach (PHAC, 2013 and 2014). The sampling found that 92% (10/11) of all Cyclospora positives were detected on conventionally grown samples, and 8% (1/11) on organic; of the total samples tested (1540), 12% were labelled organic and 88% were conventional (PHAC, personal communication). Most positives (92%) were imported samples; of the total samples tested (1540), imported samples accounted for 94% (PHAC, 2014). There is a potential for transmission to humans since herbs and leafy vegetables are often consumed without measures such as cooking or freezing which could kill or remove C. cayetanensis oocysts.

III. Request for Scientific Data and Information

Health Canada is requesting scientific data because little is known on the contamination routes or treatment options for fresh leafy vegetables contaminated with C. cayetanensis. Information of interest for this request includes, but is not limited to:

Microbiological data:

  • Any relevant microbiological data on C. cayetanensis and fresh leafy vegetables that may be available (e.g., surveillance data, environmental resistance of C. cayetanensis)
  • Information on the effect of cooking, freezing and desiccation on C. cayetanensis
  • Information on methodology, molecular typing and detection of C. cayetanensis
  • Information on the efficiency of chemical or physical disinfection on C. cayetanensis
    • Are any of these in use in fresh leafy vegetable production?

Processing-related data (for most of these interventions/processes, cost and effectiveness is of interest):

  • Information on the production, processing, transport and processing of fresh leafy vegetables in Canada and internationally
    • What interventions are available to minimize contamination of leafy vegetables with  C. cayetanensis during production?
    • What interventions are available to minimize contamination, or to remove or inactivate C. cayetanensis during processing and transportation?
    • Would some treatments be applicable to some, but not other, commodities?
  • Details on the production
    • What type of irrigation is used? Are toilets and hand washing facilities available to farm workers? Are there any other relevant production details?
  • Any epidemiological data on C. cayetanensis on fresh leafy vegetables?
    • What is the rate of infection in farm workers?

Food-related data:

  • What are the annual/monthly import volumes of fresh leafy vegetables into Canada? Which are the major exporting countries? How much is grown domestically?
  • In there a seasonal shift in exporting countries or import hubs in Canada?
  • What are the consumption rates of fresh leafy vegetables in Canada?
    • Do at-risk groups consume the food? What are the at-risk groups?
    • What are the major leafy vegetables consumed in Canada?

Preparation-related data:

  • Data relating to preparation practices and storage conditions (e.g., temperature) at food service establishments and consumer homes, i.e., methods of preparation, and packaging/processing or other extrinsic factors that may have an impact on the contamination and survival of C. cayetanensison fresh leafy vegetables.

IV. References

Public Health Agency of Canada. 2013.  2010 FoodNet Canada Short Annual Report. Available at:

Public Health Agency of Canada. 2014.  2013 FoodNet Canada Short Annual Report. Available at:

V. Information and Data

Information and data may be submitted in writing either by regular mail or electronically at the address indicated below. If you are submitting information or data electronically, please use the words “Fresh Leafy Vegetables Information” in the subject box of your e-mail.

Mailing address:

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

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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