Foodborne disease is a significant public health concern in Canada. Reducing its burden requires identifying key sources. This is the goal of foodborne source attribution which partitions the human disease burden to specific sources, including animal reservoirs and vehicles. Multiple methods for source attribution, each with distinct strengths and limitations, are needed to identify the key sources of human enteric disease. We explored the suitability of a novel application of multivariate time series regression to calculate source attribution estimates. Utilizing ecologically-linked exposure source and salmonellosis case data collected at FoodNet Canada sentinel sites, we used multivariate autoregressive integrated moving average with exogenous variables (ARIMAX) regression to examine associations between weekly Salmonella prevalence in retail frozen breaded chicken products (FBCP) and fresh chicken breast meat (CBM) and human salmonellosis incidence. The fitted models were used to estimate the impact of the 2019 Canadian Food Inspection Agency (CFIA) policy requiring no detectable Salmonella in FBCP, and to calculate FBCP and CBM source attribution percentages. Associations between Salmonella prevalence in FBCP and human salmonellosis were observed, with the strongest effects at 2- and 6-week lags when adjusting for seasonality, CBM Salmonella prevalence, and serial autocorrelation demonstrating the value of time series modeling in pinpointing specific weeks when spikes in foodborne pathogens may precede increases in human illness. Source attribution estimates were generated and were consistent with previous results for FBCP but inconsistent for CBM. Time series model-predicted estimates may be useful for source attribution under certain conditions and represent a potential addition to the source attribution toolkit.

Background: Beaches are popular summertime destinations in Canada. However, they can be affected by specific fecal pollution sources, increasing the risk of recreational water illness. Objectives: This study was conducted to determine the risks of acute gastrointestinal illness (AGI) among Canadian beachgoers and to evaluate the influence of different fecal indicator bacteria (FIB) and other water quality measures on assessing these risks. Methods: In a prospective cohort design, beachgoers were recruited at sites across Canada from 2023 to 2025. Sociodemographic characteristics and exposures were determined through an on-site survey, with a 7-day follow-up survey to determine risks of AGI. Bayesian mixed-effects logistic regression models were fitted to evaluate the effects of an ordinal water contact variable (no contact, minimal contact, body immersion, and swallowed water) on the incident risk of AGI, with an interaction included for water quality indicators. The levels of six FIB and water quality measures were assessed: Escherichia coli, enterococci DNA, three microbial source tracking DNA markers (human HF183/BacR287, human mitochondria, seagull Gull4), and turbidity. Results: A total of 4085 participants were recruited, with 67.6% completing the follow-up survey. The overall incident risk of AGI was 2.6%. Both swallowing water and body immersion increased AGI risks compared to no water contact: median of 20 excess cases (95% Credible Interval [CrI]: 4, 64) and 5 excess cases (95% CrI: 1, 19) of AGI predicted per 1000 beachgoers, respectively. Escherichia coli and seagull DNA marker levels were associated with AGI among those who had water contact, particularly among those who reported swallowing water. Discussion: While the overall burden of AGI due to beach water contact in Canada was low, increased risks are associated with E. coli levels particularly among those who swallow water. This could be related to fecal contamination from seagulls. However, there is substantial uncertainty in the predicted effect sizes. ### Competing Interest Statement The authors have declared no competing interest. ### Clinical Protocols ### Funding Statement This work was supported by the Canadian Institutes of Health Research (CIHR), grant numbers PJT 185894 and PJT 192023 (P.I. Young) ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: The Toronto Metropolitan University Research Ethics Board gave ethical approval for this work (REB# 2023-043). I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes All data produced in the present study are available upon reasonable request to the authors [https://github.com/iany33/Beach\_cohort\_AGI][1] [1]: https://github.com/iany33/Beach_cohort_AGI

Each year in Canada, an estimated 4 million cases of foodborne illness occur which result in approximately 11,600 hospitalizations and 240 deaths. These illnesses pose significant public health and economic challenges. To address this, current information on Canadians' food handling practices is essential to support evidence-based communication, food safety messaging, and policymaking. This study aimed to describe national consumer food handling behaviors and identify knowledge gaps related to food safety practices. Data were obtained from the Foodbook 2.0 survey, conducted by the Public Health Agency of Canada between 2023 and 2024. Weighted analysis was performed on this nationally representative dataset, with demographic disaggregation to identify high-risk groups and determine the prevalence of unsafe food handling behaviors. Men were more likely than women to refrigerate leftovers more than six hours after cooking (8.4% vs. 5.6%). About 30.0% (95%CI: 29.9-31.0) of respondents rinsed meat or poultry before cooking it "all of the time", with 25.0% (95%CI: 24.1-26.1) of respondents "sometimes" engaging in this practice. The most common method for checking meat doneness was visual inspection (73.6%; 95%CI: 72.6-74.6). These findings highlight the continued importance of targeted food safety education, particularly focusing on proper storage, safe handling of raw meat and poultry, and the use of food thermometers. These results indicate how messaging could be tailored to demographic groups engaging in higher-risk behaviors.

BackgroundRecreational water activities at beaches are popular among Canadians. However, these activities can increase the risk of recreational water illnesses (RWI) among beachgoers. Few studies have been conducted in Canada to determine the risk of these illnesses. This protocol describes the methodology for a study to determine the risk and burden of RWI due to exposure to fecal pollution at beaches in Canada.MethodsThis study will use a mixed-methods approach, consisting of a prospective cohort study of beachgoers with embedded qualitative research. The cohort study involves recruiting and enrolling participants at public beaches across Canada, ascertaining their water and sand contact exposure status, then following-up after seven days to determine the incidence of acute RWI outcomes. We will test beach water samples each recruitment day for culture-based E. coli, enterococci using rapid molecular methods, and microbial source tracking biomarkers. The study started in 2023 and will continue to 2025 at beaches in British Columbia, Manitoba, Ontario, and Nova Scotia. The target enrollment is 5000 beachgoers. Multilevel logistic regression models will be fitted to examine the relationships between water and sand contact and RWI among beachgoers. We will also examine differences in risks by beachgoer age, gender, and beach location and the influence of fecal indicator bacteria and other water quality parameters on these relationships. Sensitivity analyses will be conducted to examine the impact of various alternative exposure and outcome definitions on these associations. The qualitative research phase will include focus groups with beachgoers and key informant interviews to provide additional contextual insights into the study findings. The study will use an integrated knowledge translation approach.DiscussionInitial implementation of the study at two Toronto, Ontario, beaches in 2023 confirmed that recruitment is feasible and that a high completion rate (80%) can be achieved for the follow-up survey. While recall bias could be a concern for the self-reported RWI outcomes, we will examine the impact of this bias in a negative control analysis. Study findings will inform future recreational water quality guidelines, policies, and risk communication strategies in Canada.

Nontyphoidal Salmonella enterica infections are a leading cause of enteric disease in Canada, most commonly associated with foodborne exposures. Raw frozen breaded chicken products (FBCP) have been implicated in 16 Salmonella outbreaks between 2017 and 2019. This study quantified the impact of the 1 April 2019 requirement by the Canadian Food Inspection Agency (CFIA) for manufacturers to reduce Salmonella in raw FBCP. An intervention study approach utilizing the pre-post intervention data with a comparison group methodology was used to: (1) estimate the reduction in FBCP Salmonella prevalence using retail meat FoodNet Canada data; (2) estimate the reduction in the human salmonellosis incidence rate using data from the Canadian National Enteric Surveillance Program; and (3) estimate the proportion of reported cases attributed to FBCP if the human exposure to Salmonella through FBCP was completely eliminated. The FBCP Salmonella prevalence decreased from 28% observed before 1 April 2019 to 2.9% after the requirement implementation. The CFIA requirement was estimated to reduce the human salmonellosis incidence rate by 23%. An estimated 26% of cases during the pre-intervention period can be attributed to FBCP. The CFIA requirement was successful at significantly reducing Salmonella prevalence in retail FBCP, and at reducing salmonellosis burden.

In May 2017, whole-genome sequencing (WGS) became the primary subtyping method for Salmonella in Canada. As a result of the increased discriminatory power provided by WGS, 16 multi-jurisdictional outbreaks of Salmonella associated with frozen raw breaded chicken products were identified between 2017 and 2019. The majority (15/16) were associated with S. enteritidis, while the remaining outbreak was associated with S. Heidelberg. The 16 outbreaks included a total of 487 cases with ages ranging from 0 to 98 years (median: 24 years); 79 hospitalizations and two deaths were reported. Over the course of the outbreak investigations, 14 frozen raw breaded chicken products were recalled, and one was voluntarily withdrawn from the market. After previous changes to labelling and the issuance of public communication for these products proved ineffective at reducing illnesses, new industry requirements were issued in 2019, which required the implementation of measures at the manufacturing/processing level to reduce Salmonella to below detectable amounts in frozen raw breaded chicken products. Since implementation, no further outbreaks of Salmonella associated with frozen breaded chicken have been identified in Canada, a testament to the effectiveness of these risk mitigation measures.

Salmonella is a major cause of enteric disease in Canada. Cases of salmonellosis were attributed to retail meats, food animal manure contact, and surface water sources using a microbial subtyping approach coupled with adjustments for exposure. Results indicated that 64.7% of cases were attributed to chicken breast meat, followed by frozen raw breaded chicken products (12.9%), ground chicken (9.1%), water (3.0%), pork chops and sausage (1.3%), ground beef and veal (0.7%), turkey parts (0.5%), and molluscs (0.0%). The salmonellosis incidence rate in the FoodNet Canada sentinel sites fell by one third with a parallel drop of one third in the percent of cases attributed to chicken breast meat between 2015 and 2019. Decreases in the contribution of many of the top serovars to the percentage of cases attributed to chicken breast meat indicates some emerging success with broiler breeder chicken vaccination programs. In addition, preliminary prevalence results for frozen raw chicken products in late 2019 suggests the Canadian Food Inspection Agency intervention in 2019 requiring any Sal-monella on these products to be below a detectable amount may be having an impact, though more data post intervention is needed to be more conclusive.

Nontyphoidal Salmonella (NTS) is a leading cause of acute gastrointestinal illness in Canada, and reported cases have been on the rise since the early 2000s. To address this trend, agri-food industry partners and government have worked to identify and implement interventions, guided by the enhanced information provided by whole-genome sequencing, to reduce the incidence of NTS. A substantial reduction in the number of NTS cases reported occurred in 2019. Due to underreporting and underdiagnosis factors, the observed decrease in the number of reported cases represents a fraction of the true number of illnesses averted in the community. The objective of this study was to: (1) use burden of illness estimation methodologies to estimate the true number of NTS illnesses, hospitalizations, and deaths prevented, and (2) estimate the economic savings associated with the prevention of these cases. Compared with the previous 5 years, there were an estimated 25,821 fewer illnesses, 213 fewer hospitalizations, and 2 fewer deaths attributable to NTS in 2019. This corresponds to an estimated reduction of 26.9 million Canadian dollars in the economic burden of NTS. Although causality cannot be proven by this study, the findings are suggestive that the strategically implemented suite of public health actions, including genomic-based surveillance, policy changes, and interventions by the government and industry, were successful in reducing the economic and health burden of NTS infections in Canada.

Many foods have the potential to cause foodborne illness; however, some pose a higher risk. Data were collected through the Foodbook study, a population-based telephone survey conducted between 2014 and 2015 that assessed 10,942 Canadians' food exposures using a 7-day recall period. The 19 foods included in the survey were identified as high risk for common foodborne pathogens in Canada. Results were analyzed by age group, gender, region of residence, income, and education. Consumption proportions of high-risk foods ranged from 0.4% (raw oysters) to 49.3% (deli meats). Roughly 94% of the population reported consuming one or more high-risk food in the past week. Certain high-risk food behaviors were associated with demographic characteristics. High-risk adults such as those 65 years or older still report consuming high-risk foods of concern, including deli meats (41.8%), soft cheeses (13.7%), and smoked fish (6.3%). Consumption of certain foods differed between genders, with males consuming significantly more deli meats, hot dogs, and raw or undercooked eggs and females consuming significantly more prebagged mixed salad greens. The overall number of high-risk foods consumed was similar, with both genders most frequently consuming three to five high-risk foods. High-risk food consumption was seen to increase with increasing household income, with 14.2% of the highest income level consuming six-plus high-risk foods in the past week, compared with 7.1% of the lowest income level. If a respondent had heard of a risk of foodborne illness associated with a food, it did not affect whether it was consumed. Additional consumer food safety efforts put in place alongside current messaging may improve high-risk food consumption behaviors. Enhancing current messaging by using multifaceted communications (e.g., social media and information pamphlets) and highlighting the large incidence and severity of foodborne illnesses in Canada are important strategies to improve behavior change.

Background. The early detection of enteric infections in older adults is challenging because typical signs and symptoms of disease may be less common, absent, or overlooked. Understanding illness characteristics of enteric infections among older adults could improve the timeliness and accuracy of clinical diagnoses, thereby improving patient outcomes and increasing cases reported to surveillance. Methods. Here, we describe illness characteristics (percentage reporting bloody diarrhea, fever, vomiting, abdominal pain; percentage hospitalized; duration of hospitalization; and duration of illness) among older adults (>= 65 years) with acute gastroenteritis and culture-confirmed Campylobacter and nontyphoidal Salmonella infections in Australia, Canada, and the United States and compare these characteristics with those among younger people (<5 years, 5-24 years, and 25-64 years). Results. A significant negative correlation was found between all symptoms and increasing age group, except for bloody diarrhea in cases of acute gastroenteritis. Adults aged >= 85 years reported bloody diarrhea in only 9% of nontyphoidal Salmonella and 4% of Campylobacter infections compared with 59% and 55% among children aged <5 years. Conversely, a greater percentage of older adults (>= 65) than younger persons (<5, 5-24, 25-64) reported being hospitalized, with an increasing linear relationship in age groups 65 years and older. Conclusions. Although older adults are more likely to have severe illness and be hospitalized, we found that the proportion of persons reporting symptoms typically associated with enteric infections decreases with age. These findings have implications for clinical recognition and treatment of gastrointestinal illness, as well as for public health research.

Animal companionship can have many physical and psychological benefits; however, animals can also be a source of zoonotic infection, including enteric illnesses; it has been estimated that in Canada, nearly 85,000 enteric illnesses due to eight pathogens occur each year related to animal contact. There is a lack of baseline data on animal-related exposures in Canada and around the world. This information is critical to inform quantitative and qualitative risk assessments to prioritize intervention efforts in public health and reduce the associated burden of enteric illness. To help address this issue and assist evaluation of the risks associated with animal contact, the Foodbook study, conducted in 2014-2015, assessed exposure to animals, animal food and animal-related venues within the last 7days among Canadians. Data were analysed by province and territory, age group and urban/rural residency. Overall, dogs and cats were the most commonly reported animal exposures (43.3% and 31.9%, respectively). The data suggest farm animal exposure occurs primarily at a farm/barn, and to a lesser extent at other animal-related venues (e.g., petting zoos or agricultural fairs). Approximately one in 25 respondents handled raw pet food within the last 7days; the majority of which had also been exposed to a dog (86.4%). Children aged 0-9years reported relatively high exposure to four types of high-risk animals: rodents (5.6%), poultry (4.0%), reptiles (2.1%) and amphibians (1.8%); with the most vulnerable children aged <5years also reporting exposure to many of these high-risk animals. These results highlight potential areas for targeted intervention that can focus on high-risk populations (e.g., young children) exhibiting potentially risky behaviour such as being exposed to certain high-risk animals, or handling pet food, treats and raw pet food diets. Additionally, these results support the need to better understand the burden of enteric illness associated with animals and their environments.

In Canada, over 400,000 enteric diseases related to drinking water occur each year, highlighting the importance of understanding sources of Canadians' drinking and recreational water exposures. To address this need, a population-based telephone survey of 10,942 Canadians was conducted between 2014 and 2015, assessing Canadian's drinking water sources and recreational water exposures using a seven-day recall method. Results were analyzed by province/territory, season, age group, gender, income, education, and urban/rural status. Store-bought bottled water was reported by nearly 20% of survey respondents as their primary drinking water source, while approximately 11% of respondents reported private well. The proportion of private well users was significantly greater than the national average in the Maritime Provinces where approximately 40-56% of respondents reported this as their primary drinking water source. As expected, Canadians' recreational water activities and exposures (e.g., swimming, pool, lake, and waterpark) peaked during summer and were most commonly reported among children aged 0-9 years. Waterborne disease in Canada requires a multi-faceted public health approach. Canadian baseline data on water exposures can inform policy and public health strategies (e.g., recreational water guidelines, private well water testing recommendations) and support research and risk assessment related to mitigating waterborne illness.

Salmonella infections remain an important public health issue in Canada and worldwide. Although the majority of Salmonella cases are self-limiting, some will lead to severe symptoms and occasionally severe invasive infections, especially in vulnerable populations such as seniors. This study was performed to assess temporal trends of Salmonella cases in seniors over 15 years (2014-2028) and assess possible impact of demographic shift on national incidence; taking into account of trends in other age groups. The numbers of reported Salmonella cases in seniors (60 years and over) in eight provinces and territories for a period of fifteen years were analysed (1998-2013) using a time-adjusted Poisson regression model. With the demographic changes predicted in the age-structure of the population and in the absence of any targeted interventions, our analysis showed the incidence of Salmonella cases in seniors could increase by 16% by 2028 and the multi-provincial incidence could increase by 5.3%. As a result, the age distribution amongst the Salmonella cases is expected to change with a higher proportion of cases in seniors and a smaller proportion in children (0-4 years old). Over the next decades, cases of infection, hospitalizations and deaths associated with Salmonella in seniors could represent a challenge to public health due to an aging population in Canada. As life expectancy increases in Canada, identification of unique risk factors and targeted prevention in seniors should be pursued to reduce the impact of the demographic shift on disease incidence.

SUMMARY Salmonella is one of the most prevalent bacteria associated with enteric illness in Canada and seniors are considered a vulnerable population more likely to develop severe illness. In the coming decades, hospitalizations and deaths associated with Salmonella in seniors could represent a challenge due to an aging population in Canada. The numbers of non-typhoidal (NT) Salmonella-related hospitalizations from the Canadian Hospitalization Morbidity Database were analysed for a period of 10 years for seniors. Hospitalization rate calculations and descriptive analyses were performed on variables associated with the burden of hospitalization and compared with the adult age group. Estimates of hospitalizations and deaths associated with domestically acquired Salmonella (accounting for under-reporting) were also calculated. This study found that 50% of the NT Salmonella-related hospitalization and 82% of the deaths recorded in the Canadian adult population occurred in seniors. The length of hospitalization stay was also longer in seniors (7 days) than other adults (4 days). We estimated that each year, 535 hospitalizations and 27 deaths are related to domestically acquired Salmonella in seniors. Senior populations represent a substantial percentage of Salmonella-related hospitalizations and deaths in Canada and the burden associated with those hospitalizations is also greater. This should be considered when developing estimates of medical costs and implementing prevention activities.

Understanding consumers' food safety practices and knowledge supports food safety education for the prevention of foodborne illness. The objective of this study was to describe Canadian consumer food safety practices and knowledge. This study identifies demographic groups for targeted food safety education messaging and establishes a baseline measurement to assess the effectiveness of food safety interventions over time. Questions regarding consumer food safety practices and knowledge were included in a population-based telephone survey, Foodbook, conducted from November 2014 to March 2015. The results were analyzed nationally by age group and by gender. The results showed that approximately 90% of Canadians reported taking the recommended cleaning and separating precautions when handling raw meat to prevent foodborne illness. Only 29% of respondents reported using a food thermometer when cooking any meat, and even fewer (12%) reported using a food thermometer for small cuts of meat such as chicken pieces. The majority (>80%) of Canadians were aware of the foodborne illness risks related to chicken and hamburger, but fewer (<40%) were aware of the risks related to frozen chicken nuggets, alfalfa sprouts, soft unpasteurized cheese, and unpasteurized juices. Generally, men were less likely to follow cooking instructions on packaging and took fewer steps to prevent cross-contamination than women. The youngest (18 to 29 years) age group was less likely to take steps to avoid cross-contamination and was less aware of the risks associated with eating an undercooked hamburger. The oldest (60+ years) respondents were less likely to be aware of the risks associated with raw eggs, alfalfa sprouts, and unpasteurized juice than the middle (30 to 59 years) age group. As a priority, food safety education in Canada should focus on increasing people's awareness of high-risk foods, specifically foods for which the awareness of risk found in this study was low; targeting messaging to demographic groups as appropriate; and promoting the use of food thermometers when cooking meat and poultry.

Acute gastrointestinal illness (AGI) is an important public health issue, with many pathogen sources and modes of transmission. A one-year telephone survey was conducted in Canada (2014-2015) to estimate the incidence of self-reported AGI in the previous 28 days and to describe health care seeking behaviour, using a symptom-based case definition. Excluding cases with respiratory symptoms, it is estimated that there are 0.57 self-reported AGI episodes per person-year, almost 19.5 million episodes in Canada each year. The proportion of cases seeking medical care was nearly 9%, of which 17% reported being requested to submit a sample for laboratory testing, and 49% of those requested complied and provided a sample. Results can be used to inform burden of illness and source attribution studies and indicate that AGI continues to be an important public health issue in Canada.

Campylobacteriosis, the most frequent bacterial enteric disease, shows a clear yet unexplained seasonality. The study purpose was to explore the influence of seasonal fluctuation in the contamination of and in the behaviour exposures to two important sources of Campylobacter on the seasonality of campylobacteriosis. Time series analyses were applied to data collected through an integrated surveillance system in Canada in 2005-2010. Data included sporadic, domestically-acquired cases of Campylobacter jejuni infection, contamination of retail chicken meat and of surface water by C. jejuni, and exposure to each source through barbequing and swimming in natural waters. Seasonal patterns were evident for all variables with a peak in summer for human cases and for both exposures, in fall for chicken meat contamination, and in late fall for water contamination. Time series analyses showed that the observed campylobacteriosis summer peak could only be significantly linked to behaviour exposures rather than sources contamination (swimming rather than water contamination and barbequing rather than chicken meat contamination). The results indicate that the observed summer increase in human cases may be more the result of amplification through more frequent risky exposures rather than the result of an increase of the Campylobacter source contamination.

OBJECTIVES:Human infection with Escherichia coli O157:H7/NM has historically been associated with consumption of undercooked ground beef. The purpose of this paper is to investigate the correlation of the decline in E. coli O157:H7/NM infections in Canada with the introduction of control efforts in ground beef by industry.METHODS:The human incidence of E. coli O157:H7/NM, prevalence in ground beef and interventions from 1996 to 2014 were analyzed. Pathogen prevalence data were obtained from federal government and industry surveillance and inspection/compliance programs. A survey of the largest ground beef producers in Canada was conducted to identify when interventions were implemented.RESULTS:The incidence of E. coli O157:H7/NM infections in Canada declined from ≈4 cases/100 000 to ≈1 case/100000 from 2000 to 2010. Verotoxigenic Escherichia coli (VTEC) prevalence in ground beef sold at retail declined from about 30% around the year 2000 to <2% since 2012. Other measures of the prevalence of E. coli, VTEC, and E. coli O157:H7/NM in beef and ground beef also declined. The number and types of interventions implemented in the major beef processing establishments in Canada increased from 1996 to 2016.CONCLUSION:The observed decline in human illnesses and pathogen levels in relation to retail meats was associated with the introduction of control efforts by industry, federal and provincial/territorial governments, and the general population. Industry-led changes in beef processing along with the introduction of food safety policies, regulations, and public education have led to improved food safety in Canada.

To inform source attribution efforts, a comparative exposure assessment was developed to estimate the relative exposure to Campylobacter, the leading bacterial gastrointestinal disease in Canada, for 13 different transmission routes within Ontario, Canada, during the summer. Exposure was quantified with stochastic models at the population level, which incorporated measures of frequency, quantity ingested, prevalence, and concentration, using data from FoodNet Canada surveillance, the peer-reviewed and gray literature, other Ontario data, and data that were specifically collected for this study. Models were run with @Risk software using Monte Carlo simulations. The mean number of cells of Campylobacter ingested per Ontarian per day during the summer, ranked from highest to lowest is as follows: household pets, chicken, living on a farm, raw milk, visiting a farm, recreational water, beef, drinking water, pork, vegetables, seafood, petting zoos, and fruits. The study results identify knowledge gaps for some transmission routes, and indicate that some transmission routes for Campylobacter are underestimated in the current literature, such as household pets and raw milk. Many data gaps were identified for future data collection consideration, especially for the concentration of Campylobacter in all transmission routes.

The observed decline in human illnesses and pathogen levels in relation to retail meats was associated with the introduction of control efforts by industry, federal and provincial/territorial governments, and the general population. Industry-led changes in beef processing along with the introduction of food safety policies, regulations, and public education have led to improved food safety in Canada.