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Two Agroenvironmental hygienic pressure indicators (AHPIs) were developed to evaluate the effects of livestock production on water contamination and the risk for human health by expressing a complex public health risk via simple quantifiable figures. The first of the two AHPIs is addressing the aspect of surface water contamination while the second one is dealing with groundwater contamination. Each of the two AHPIs is built from a multiplicative model based on 25 parameters related to the transmission of bacteria through excretion by animals, survival in manure, and by run-off or infiltration water produced by rainfall. A global sensitivity approach was used to identify the most significant parameters in regard to the AHPIs output results. This analysis found that bacterial survival on the soil after manure spreading or grazing of animals (Ks), the proportion of bacteria able to reach surface water with run-off from manure on the soil (Brun-off), bacteria concentration in faeces Bconc, within-herd proportion of animals shedding the pathogenic bacteria targeted (Bprev) and the area used for pasture (A) – on bovine farms – are the most influential parameters with respect to the estimation of the AHPIs. With the exception of the latter element, these factors are all directly related to bacterial characteristics and parameters for which obtaining high quality data is most challenging. The identification of these most influential parameters will guide further research to enhance both the precision application of the AHPIs, and their use in managing public health risks.

Two Agroenvironmental Hygienic Pressure Indicators (AHPIs) have been proposed as model-based indicators for the public health risk of surface and ground water contamination by enteropathogens from agroenvironmental sources. Each of these indicators summarises twenty five parameters. The scientific goal of this work was to assess in an ex-ante way the usefulness of these indicators. One of the major reasons why many models and indicators fail to be used is the lack of the necessary data. Hence, the first step of the study assessed the availability of the data necessary for computing the AHPIs for the province of Quebec. Another reason for lack of usage is if the indicators do not meet the needs of the targeted audience. Consequently, this article also demonstrates key aspects of the AHPIs that make them a tool that is likely to be useful for the end-user. The evaluation of the availability and quality of available data for use in the AHPI led to minor modifications to the AHPI original parameters and equations. These modifications are presented. Once modified, adequate data were acquired to compute the indicator for Escherichia coli for surface and groundwater for all livestock farms in the province of Quebec, Canada. Data related to the microbial aspect of the AHPIs such as pathogen presence in livestock, its survival time in storage or on the soil, and its movement with water were the most difficult to obtain. For example, E. coli was used as a general indicator of faecal contamination in the absence of province-wide data on intra-herd contamination by specific human enteropathogens. Maps were generated and interpreted for their biophysical meaning to illustrate how the indicator values could be interpreted by various stakeholders involved in the public health management of water contamination from animal agriculture production and how this could be useful.

Human illness attribution has been recently recognized as an important tool to better inform food safety decisions. Analysis of outbreak data sets has been used for that purpose. This study was conducted to explore the usefulness of three comprehensive Canadian foodborne outbreak data sets covering 30 years for estimating food attribution in cases of gastrointestinal illness, providing Canadian food attribution estimates from a historical perspective. Information concerning the microbiological etiology and food vehicles recorded for each outbreak was standardized between the data sets. The agent-food vehicle combinations were described and analyzed for changes over time by using multiple correspondence analysis. Overall, 6,908 foodborne outbreaks were available for three decades (1976 through 2005), but the agent and the food vehicle were identified in only 2,107 of these outbreaks. Differences between the data sets were found in the distribution of the cause, the vehicle, and the location or size of the outbreaks. Multiple correspondence analysis revealed an association between Clostridium botulinum and wild meat and between C. botulinum and seafood. This analysis also highlighted changes in food attribution over time and generated the most up-to-date food attribution values for salmonellosis (29% of cases associated with produce, 15% with poultry, and 15% with meat other than poultry, pork, and beef), campylobacteriosis (56% of cases associated with poultry and 22% with dairy products other than fluid milk), and Escherichia coli infection (37% of cases associated with beef, 23% with cooked multi-ingredient dishes, and 11% with meat other than beef, poultry, and pork). Because of the inherent limitations of this approach, only the main findings should be considered for policy making. The use of other human illness attribution approaches may provide further clarification.

Active monitoring of pathogens on retail foods has been recommended and implemented in a number of developed countries. Because only a portion of retail food is contaminated with pathogens, a cost-effective and informative surveillance program at the retail level often involves a two-stage approach of initial presence-absence analysis and subsequent pathogen enumeration in any positive samples. Most-probable-number (MPN) methods are more resource intensive and therefore used only for samples considered positive by presence-absence methods. Interpretation of the results assumes that the initial bacterial count remains relatively stable between the initiation of the presence-absence analysis and the enumeration analysis. The objective of this study was to quantify the influence of 4 degrees C storage for 5 and 8 days on pathogen counts on raw chicken. The three pathogens examined were Salmonella Typhimurium, Campylobacter jejuni, and Listeria monocytogenes. No significant differences were found between treatments for Salmonella and Campylobacter. However, significant differences were observed for Listeria; counts at day 0 were lower than counts after 5 or 8 days of refrigerated storage (the maximum mean difference was less than 0.6 log units). These findings suggest that a two-stage approach could overestimate the number of Listeria cells on chicken at the time of purchase. By using an MPN analysis on the presumptive positive samples after 5 days of refrigerated storage, this difference will be reduced. These findings support the decision to reduce surveillance costs by performing a two-stage analysis for Salmonella and Campylobacter on retail chicken. This study provides direction for future sampling or surveillance programs that include enumeration of Listeria on retail food.

A cross-sectional study was implemented to determine which factors related to management, housing and stockperson in the farrowing quarters were associated with preweaning mortality and piglets weaned per litter in swine breeding herds. The associations were sought separately for the two most common types of swine production in Quebec. Forty-eight randomly-selected independent farms and 38 others belonging to integrated organizations specialized in swine production conveniently chosen among the largest organizations in Quebec participated in the study. Preweaning performances were computed from the sow records. Information on housing features was gathered during the visit to the farrowing quarters. Management practices were obtained through a questionnaire from the stockperson working in the farrowing quarters and his or her personality traits were evaluated through a personality test. Backward elimination procedure was used to build multiple linear regression models for each measure of performance for each type of farm. The procedures started from the management, housing and stockperson groups of variables taken separately and altogether, leading to the building of different regression models. Piglets weaned per litter averaged 8.9 and 8.6 on the independent and integrated farms, respectively and preweaning mortality, 14.4 and 15.4%, respectively. On the independent farms, high preweaning performances (high number of piglets weaned per litter and low preweaning mortality) were associated with routinely washing the farrowing crates, vaccination of the sows against neonatal diarrhea, farrowing crates equipped with high bottom bars, partially-slotted floors in the farrowing pens and high self-discipline from the stockperson. Poor performances were associated with the use of oxytocin around farrowing, mixed nursery-farrowing quarters and a stockperson being exaggeratedly self-assured and sensitive. On the integrated farms, the use of oxytocin at farrowing was also associated with poor performances, as well as several rooms or all-in/all-out farrowing quarters, farrowing crates equipped with high or medium bottom bars, totally-slotted floors and a stockperson being rather bold, suspecting and tense. High performances were positively associated with warmth, emotional stability and self-discipline from the stockperson. These findings provided evidences of the influence of the stockperson's personality on performances in particular, on the integrated farms on which the management in the farrowing quarters was more proactive (implying a stronger relationship between the stockperson and the pigs). In contrast, the importance to preweaning performances of general hygiene and health control was emphasized on the independent farms.