Regardless of the food commodity, intervention-based Hazard Analysis and Critical Control Points (HACCP), HACCP-like or Good Agricultural Practices/Good Manufacturing Practices (GAP/GMP) are recommended and frequently in place at various points in the food production and processing environment continuum to control microbiological hazards that may be present; this includes VTEC. Historically, in Canada, the major hazard considered in this category has been VTEC O157:H7/NM. Regardless, there is no evidence that non-O157 VTEC and VTEC O157 are significantly different in their resistance to environmental stresses and decontamination processes currently in place in food processing (Kundu et al., 2014; Liu et al., 2015; Gill et al., 2019b). Thus, it can be expected that those systems which effectively control VTEC O157:H7/NM will also control other VTEC.
Healthy cattle and other domestic ruminants are known to be carriers of VTEC, which can be transferred to meat and milk during harvest. A wide range of pre-harvest interventions to minimize the presence of VTEC O157:H7 in cattle have been investigated including: changes to animal management and transportation, diet, hygiene of feed, water and bedding, feed additives, antimicrobial and bacteriophage treatments, vaccination and pre-slaughter hide washing. While there is no intervention that has been demonstrated to prevent VTEC carriage in cattle or other ruminants or to reliably reduce VTEC shedding in feces, adherence to industry best practices with regards to cattle management and hygiene of food, water and transportation can help minimize VTEC along the food chain (Swaggerty et al., 2018).
In Canada, the meat production sector is regulated and receives oversight from federal, provincial and municipal authorities. National baseline studies on the prevalence on VTEC O157:H7/NM have been conducted over the years and have helped in establishing inspection activities and domestic monitoring processing programs by regulatory authorities. No national level data (baseline study) is available at this time on the presence of non-O157 VTEC in domestic beef cattle. Food safety efforts, up to the present, have been largely focused on mitigating the risk from VTEC O157:H7/NM.
Beef processing is normally done in several stages, and various treatments (physical or chemical interventions) can be used along the processing chain to remove or inactivate pathogens if present. These interventions (e.g., chemical solutions, hot water treatment, etc.) can be applied at post-stunning, pre-evisceration and/or post-evisceration stages. The adoption of processing interventions at the major Canadian beef slaughter plants is correlated with a decline in the frequency of VTEC O157 contamination of beef and cases of human illness in Canada (Pollari et al., 2019).
To reinforce and enhance the application of preventative programs as well as help mitigate risk from VTEC O157:H7 a number of guidance documents have been issued at the federal level (Table 12.). Products which are the subject of guidance include: raw ground beef and precursor material; ready-to-eat fermented sausages, mechanically tenderized beef, and donair type meats.
Milk and Dairy Products
Milk and dairy products producers and/or processors in Canada may receive federal or provincial oversight. Dairy farmers through the Dairy Farmers of Canada have adopted and implemented on-farm food safety program (the Canadian Quality Milk Program) that uses a HACCP based approach to help mitigate bacterial hazards, amongst others, in their products. Producers monitor critical areas relevant to food safety specifically: effective cooling and storage of milk, sanitation of equipment, and cleanliness of water.
Liquid milk must be pasteurized prior to sale in Canada (as per Food and Drug Regulations- FDR- (C.R.C., c. 870), B.08.002.2 (1)). It is expected that this treatment will control all strains of VTEC that might be present in raw milk. However, cheese made from unpasteurized milk is allowed for sale (B.08.002.2 (2a)).
Fresh fruits and vegetables are frequently consumed in their raw state and thus represent a concern for public health because outbreaks involving these commodities often affect a large number of individuals.
In Canada, there are a number of programs aimed at proactively managing potential sources of contamination of fresh fruits and vegetables. Programs, such as the industry developed CanadaGAP, are based on GAP as described by the Codex Alimentarius, with the aim of preventing microbiological contamination, minimizing public health impacts when contamination occurs and improving communication. The on-farm Food Safety Enhancement Program is a similar program, based on HACCP principles that complies with Federal, provincial/territorial requirements for food safety management (CFIA, 2018).
Specific guidance has been issued to help minimize the public health impact of contamination by bacterial pathogens of unpasteurized fruit juice/cider and sprouts from seeds and beans (Table 12).