Evaluation of public health interventions in shellfish tag compliance rates

Abstract

Background: The recent Vibrio parahaemolyticus outbreak in the summer of 2015 highlighted that shellfish tags are one of the key pieces of information used to trace back and determine the source of a foodborne outbreak or illness associated with raw or uncooked shellfish. According to the Canadian Food Inspection Agency, all shellfish tags must meet the requirements stated in the Section 7.3 of the Canadian Shellfish Sanitation Program (CSSP). Non-compliant tags may hinder national and regional regulatory agencies from identifying problems in harvest locations and at the processors, and further impede provincial control measures. As a result of the national outbreak, the BC Center for Disease Control (BCCDC), Ministry of Agriculture and the Canadian Food Inspection Agency (CFIA), as well as health authorities and Environmental Health Officers (EHO) have been involved in a variety of actions and interventions to improve compliance. These include efforts to promote education and to improve control and surveillance of V. parahaemolyticus and other shellfish associated illnesses. This study examined the effectiveness of health agencies’ interventions to improve shellfish tag compliance rates to Section 7.3 of the CSSP by comparing the numbers of shellfish tags in compliance before and after the interventions that were implemented in 2016. Methods: 120 randomly selected shellfish tags were grouped into “Before” and “After” interventions. By assessing the date of processing, 60 tags collected before September 2016 were placed into the “Before” group. Another 60 tags collected after September 2016 were placed into the “After” group. Within each group, shellfish tags were individually analyzed to determine whether the tag met or exceeded the required quality, information, and type and quantity criteria. Shellfish tags were considered “Compliant” if they completely fulfill 10 components embodied in the criteria, whereas shellfish tags that failed to meet all the components were labeled “Non-compliant”. Results: Based on the statistical analysis conducted on the data, there was a greater proportion of compliant shellfish tags post-intervention compared to pre-intervention. The Pearson’s Chi-square test confirmed that there was a statically significant association (p-value = 0.000) between the numbers of shellfish tags in compliance and the interventions that were implemented after the outbreak. Conclusion: The results have demonstrated that the interventions implemented by numerous regulatory authorities resulted in greater compliance to Section 7.3 of the CSSP. Public health regulators including the Ministry of Agriculture and the CFIA, as well as BCCDC and EHOs should continuously be involved in a variety of actions, such as promoting education at the processor and retail level and also implementing interventions to improve compliance. By doing so, successful interventions and increased compliance rates will lead to rapid identification of shellfish-related illnesses or outbreaks and facilitate control measures that can expeditiously remediate public health issues.