Foodborne Risk Research Articles

Assessing foodborne outbreak risks in Chinese households: A national survey analysis of pork handling practices

ObjectiveThis study aimed to assess the risk of foodborne outbreaks associated with household food handling practices in China and identify the consumer groups that are at higher risk for foodborne outbreaks. MethodsA national survey of household pork handling practices was conducted in China. The risk of foodborne outbreaks stemming from consumers’ improper handling practices was assessed utilizing the Weighted Harmonic Outbreak Prevention Index (WHOPI). The index categorized these practices into three levels of good hygienic practice (GHP): low (WHOPI≤0.35), medium (WHOPI: 0.36–0.70), and high (WHOPI>0.7). Logistic regression analyses were used to identify groups at higher risk for foodborne outbreaks. ResultsA total of 2730 households from seven provinces in mainland China were analyzed. Based on WHOPI, only 0.4 % of households demonstrated a high level of GHP, while 55.4 % showed a low level of GHP. The primary non-conforming stage was separation practices, followed by cooking and purchasing practices. Nearly two-thirds of households (64.8 %) didn’t have a separate cutting board for raw meat, and 44.9 % of them claimed to use the same board to handle ready-to-eats afterward. Logistic regression indicated more attention is required for those living in southern and rural areas, working in non-public institutions, possessing lower levels of education, and being single or widowed. ConclusionThe household food handling practices of Chinese consumers involve serious food safety risks. Education programs and interventions concerning safe handling practices in households are urgently needed.

Food-borne disease risk: biosurveillance in water networks.

Food-borne disease risk: biosurveillance in water networks.

Analysis of spore prevalence and sporulation potential in prepackaged meat products

Spores are recognized as significant factors affecting the safety of prepackaged meat products. However, current knowledge about the prevalence and distribution of spores in these products is limited. This study investigated 360 commonly consumed prepackaged meat products sourced from Zhengzhou, Henan Province, to assess spore prevalence, species, and characteristics. Using the 16 S rRNA method, primary spore species were isolated and identified. The results revealed a spore prevalence of 60.6% (218/360), identifying eight distinct bacterial species. In laboratory cultivation, Bacillus. Subtilis exhibited the highest spore sporulation efficiency at 95.1%, indicating a significant foodborne risk. Under the storage condition of −4 °C, the spore in food (starch sausage) maintained stable dormant state within 60 days. Additionally, Raman spectroscopy was employed to analyze the biochemical components of the cultured spores, accurately classifing eight species of spores using linear discriminant analysis (LDA). The high percentage of spore contamination in prepackaged meat products poses a potential health risk to consumers. An enhanced understanding of spore prevalence, sporulation potential, and storage methods in these products can empower industries to adjust measures effectively, controlling spore pollution in meat products.

Safe plates in the school space: Investigating compliance of food safety standards among school-based food service providers

Enhancing food safety measures within School-Based Food Service Providers (SBFSPs) is essential to safeguarding the well-being of students and school staff against foodborne risks. This study aims to assess the compliance of SBFSPs in primary and secondary schools with documentation protocols related to Good Manufacturing Practices (GMP), Good Hygiene Practices (GHP), Hazard Analysis and Critical Control Points (HACCP), and the necessary operational permits. We conducted a descriptive-correlational study spanning from April 2020 to March 2022, involving 138 public and private elementary and high schools selected through proportional stratified sampling. Each school underwent an audit using standardized checklists for GMP, GHP, and HACCP. Descriptive statistics, Fleiss Kappa, and Pearson chi-square tests were employed for data analysis. The results indicate that the participating schools do not meet the documentation requirements for GMP/GHP (29.7%), HACCP (2.9%), and operational permits (55.1%). Additionally, the schools received a "Very Poor" rating in terms of food safety compliance, with weighted mean rating scores of 2.45 ± 0.73 (GMP/GHP), 0.09 ± 0.02 (HACCP), and 1.69 ± 0.40 (operational permits). Furthermore, a significant relationship was observed between GMP/GHP and HACCP compliance and the characteristics of SBFSPs such as school kinds, types, places, and categories. The school GMP/GHP and HACCP compliance were also associated to the health permit of SBFSP personnel, authority to operate and manage school, and food handlers training. This study emphasizes the enforcement of compliance to food safety regulations, need to provide schools with adequate facilities and infrastructure, to promote a safe food production and consumption environment. It also underscores the importance of establishing partnerships for support and educating school personnel, especially those involved in food production and consumption, about GMP/GHP and HACCP principles to ensure the safety of meals for students, teachers, and other educational stakeholders. The need for certification of food handler in schools are of paramount importance, thereby advocating for increased food safety education.

Systematic foodborne disease prevention and risk management based on infection mechanisms

Systematic foodborne disease prevention and risk management based on infection mechanisms

Understanding the role of household hygiene practices and foodborne disease risks in child stunting: a UKRI GCRF Action Against Stunting Hub protocol paper

IntroductionEnvironmental hygiene and food safety are important determinants of child stunting. This research aims to explore the relationship between child stunting and household hygiene practices and behaviours, including the availability...

Trichinella spp. in Slaughtered Pigs of India: From Neglected Disease to an Emerging Food Safety Threat for Public Health

Background. In India, Trichinella nematode worm remains highly neglected due to the paucity of research. Recent trichinellosis outbreaks in humans associated with pork meal in north India have highlighted an emerging food safety concern due to this neglected parasite. Aim. This study aimed to ascertain the existence of Trichinella species and to identify them in slaughtered pigs intended for human consumption in the Punjab and Uttaranchal regions of North India. Materials and Methods. A total of 1,194 slaughter pig tongue samples were screened in 239 pools using the double separatory funnel method for recovery of Trichinella larvae. The species of recovered larvae were confirmed by multiplex PCR assay and sequencing. A phylogenetic tree was constructed to ascertain the closest lineage. Results. This study reported 3.77% and 1.26% Trichinella positivity in pooled and individual pig samples, respectively. Pigs slaughtered in Punjab reported higher positivity (1.73%) than pigs in Uttaranchal (0.81%). Among all places, Jalandhar recorded highest positivity of 5.66%, followed by 2.22% in Nainital and 0.8% in Patiala, whereas none of the pig samples from Chandigarh, Ludhiana, Bathinda, Tehri Garhwal, Pauri Garhwal, Kashipur, Haridwar was positive. Molecular confirmation by PCR and sequencing confirmed the recovered Trichinella larvae as T. britovi and T. nelsoni. Conclusion. Trichinella parasite remained highly neglected in India; however, the detection of sylvatic Trichinella species in pigs intended for human consumption indicated the emergence of zoonotic foodborne risk at wild animal-domestic pig and human interfaces. To the best of our knowledge, this is the first study reporting T. britovi and T. nelsoni in pigs of North India. Trichinella positivity in slaughtered pigs is an early alarm for the emergence of foodborne risk from this neglected parasitic worm. Considering the importance of pigs as a source of meat and their role as a reservoir for Trichinella raised the food safety concern that warrants strict meat inspection and extensive studies on neglected parasites in India.

Implementation of Food Safety Management System and its Effects on Business Performance in an Educational Institution Restaurant.

Food safety standard implementation is fundamental to the prevention, detection, and management of foodborne risks as well as the realization of food security, protection of health, and economic sustainability of food manufacturing, processing, and distributing enterprises. The global food safety standard, Hazard Analysis and Critical Control Point (HACCP) is one such instrument deployed to promote food safety in the hospitality industry worldwide. A higher educational institution in Kenya introduced HACCP ten years ago as part of its ongoing quality improvement policy to gain the advantages of implementing the standard in the food business, and as a reaction to incidents of food contamination in its restaurant that raised concerns among the customers and the leadership. Food contaminations were experienced even after the implementation of the HACCP food safety program, which brought to the fore the pitfalls that occur due to deviations from the HACCP plans and loss of control that expose consumers to food hazards. Despite the introduction of HACCP in the institution’s restaurant in 2014, there have been incidents of lapses in food quality among which was a suspected food contamination resulting in undesired customer experiences. This study aimed to evaluate the effects of the implementation of HACCP food safety management processes on food and beverage safety and business performance at the institution’s restaurant. The specific objectives of the study were to assess the implementation of the HACCP food safety management system in food production and sales; assess the customer perceptions and confidence levels in the quality and safety of food and beverages served, and to evaluate the effects of the HACCP food safety management programme in the delivery of safe food and the general business performance at the institution restaurant. The study design was exploratory and involved a survey of restaurant customers using a structured questionnaire, and interview of key informants using an interview guide. The researcher also observed food chain processes using a checklist. The study population was primarily the management and staff of the institution restaurant as well as the client population comprising students, instructors, administrative staff, institution managers, and regulatory agency representatives. The data obtained from primary sources was complemented with secondary data. Quantitative data were analysed using descriptive statistics and results were presented in tables, graphs, and pie-charts while qualitative data were analysed thematically. The key findings of the study were that despite some challenges and complexities in the implementation of HACCP, this food safety management system had significantly reduced the incidence of food contamination in the facility. Further, based on customer perceptions and feedback, the institution had registered high customer satisfaction scores (CSAT) and customer retention rates (CRR). In addition, the institution was able to generate sustained and increasing revenues and profits for the institution. The study therefore concluded that HACCP is an important instrument for promoting and safeguarding food safety in the hospitality industry and an important tool for building customer confidence and generating revenues for food businesses. The key recommendation from this study is that the institution should address identified issues of space, equipment, staff, and supplier knowledge and skills that compromise conformity with HACCP requirements.

A One Health approach based on genomics for enhancing the Salmonella enterica surveillance in Colombia

ObjectivesThis study aimed to provide evidence of the domestic benefits of introducing an integrative genomic analysis from the One Health approach in the national surveillance of Salmonella enterica between 1997-2017 in Colombia. MethodsData on Salmonella from clinical laboratory-based surveillance between 1997-2017 and from a national cross-sectional study at chicken retail stores in Colombia were compared using a phenotypic, molecular, and genomic approaches. Additional analysis by serovar using single nucleotide polymorphism was developed to increase the resolution of the relatedness between the interfaces. ResultsLocally, the diversity and pathogenic factors of the prevalent S. enterica serovars associated with foodborne disease in Colombia were described using laboratory, pulse field gel electrophoresis, and whole genome sequencing data. For example, the resolution of pulse field gel electrophoresis allowed the description of two main foodborne clusters of Salmonella Enteritidis isolates, which were expanded to eight foodborne clades using whole genome sequencing. Likewise, virulence factors and antimicrobial resistance determinants, and mobile genetic elements that converged in the foodborne clades should be considered a public health concern in Colombia. All results by serovar were compiled in an interactive easy to share report. ConclusionWhole genome sequencing is a technology that provides a precise assessment of emerging foodborne risks such as the Salmonella foodborne clades, but it requires an integrative and continued collaboration between the stakeholders across the One Health sectors to promote appropriated actions and policies in public health.

Ready-to-eat Meat Plant Characteristics Associated with Food Safety Deficiencies During Regulatory Compliance Audits, Ontario, Canada

Food safety deficiencies in ready-to-eat (RTE) meat processing plants can increase foodborne disease risks. The purpose of this study was to identify common deficiencies and factors related to improved food safety performance in RTE meat plants in Ontario. Routine food safety audit records for licensed provincial free-standing meat processing plants (FSMPs) and abattoirs that process RTE meats were obtained and analyzed in Ontario, Canada, from 2015 to 2019. A Bayesian regression analysis was conducted to examine the association between selected plant characteristics and two outcomes: overall audit rating (pass vs. conditional pass or fail) and individual audit item fail rate. The audit rating was examined in a logistic model, while the audit item fail rate was evaluated in a negative binomial model. The majority (87.7%, n = 800/912) of audits resulted in a pass rating (compared to conditional pass or fail). The mean number of employees per plant, among 200/204 plants with employee data available, was 11.6 (SD = 20.6, range = 1–200). For the logistic regression model, FSMPs were predicted to have a much higher probability of passing audits than abattoirs (32.0% on average, with a 95% credible interval [CI] of 13.8–52.8%). The number of plant employees, water source (municipal vs. private), and types of RTE meat products produced had little to no consistent association with this outcome. The negative binomial model predicted a −0.009 points lower fail rate, on average, for audit items among FSMPs than abattoirs (95% CI: −0.001, −0.018). Meat plants producing jerky had a higher audit item fail rate compared to those that did not produce such products. The other investigated variables had little to no association with this outcome. The results found in this study can support and guide future inspection, audit and outreach efforts to reduce foodborne illness risks associated with RTE meats.

Mapping of dressed and processed poultry products in Bangladesh: Identifying the food safety risks for policy intervention

Bangladesh’s commercial poultry production is growing rapidly, including the commercial processing of poultry. This expansion of poultry processing plants is fueled by the belief that this sub-sector provides safer food and has less food-borne disease risks compared to traditional live bird markets (LBMs). The purpose of this study is to describe Bangladesh’s dressed and processed poultry production and distribution network (PDN), identify what and where quality control occurs, and suggest where improvements could be made. Engaging with PDN for dressed and processed poultry, we used in-depth interviews with key informants to identify the stakeholders involved and their connections with other poultry PDNs. In addition, we mapped out the supply and distribution of dressed and processed poultry and quality control processes occurring throughout the network. We argue that dressed and processed poultry PDNs are closely connected with traditional PDNs such as LBMs, with multiple crossover points between them. Also, there is a lack of consistency in quality control testing and a lack of meat traceability. Consequently, perceptions of dressed and processed poultry being safer than birds from LBMs needs to be treated with caution. Otherwise, unsubstantiated consumer confidence in dressed poultry may inadvertently increase the risk of food-borne diseases from these products.

A socio-ecological framework for examining foodborne parasitic infection risk

Human liver fluke infection through the consumption of raw freshwater fish is one of the foodborne parasitic infections of global concern. Despite decades of health campaign efforts, high prevalence of infection remains in different areas of the Lower Mekong Basin. This necessitates the consideration of the infection differences between places and the human-environment complexities of disease transmission. This paper used the socio-ecological model as a framework to unraveled the social science dimensions of liver fluke infection. We conducted questionnaire surveys in Northeast Thailand to gather participants’ knowledge on liver fluke infection and reasons for raw fish consumption. We synthesized our findings with prior work to identify factors influencing liver fluke infection at four socio-ecological levels. At the individual level, gender and age differences in food consumption habits and personal hygiene of open defection presented the behavioral risks. At the interpersonal level, family tradition and social gathering affected the disease risk. At the community level, physical-social-economic environments of land use and modernization, community health infrastructure and health volunteer support accounted for the varying degree of infection. At the policy level, impacts of regional and national regulations on disease control, health system organization structure, and government development projects were of concerned. The findings provide insights into how infection risks are shaped by people's behavior, social connectedness, interactions with places, and the interplay of these multi-level socio-ecological influences. The framework therefore allows a more comprehensive understanding of liver fluke infection risks to inform a culturally sensitive and sustainable disease control program.

Bacteriological quality and safety of bottle food and associated factors among bottle-fed babies attending pediatric outpatient clinics of Government Health Institutions in Arba Minch, southern Ethiopia

BackgroundMicrobial contamination of baby bottle food has been identified as a significant public health concern, especially in developing countries, but it remains overlooked. Therefore, this study aimed to determine microbiological hazards, compliance with hygiene practices, and critical control points of contamination in baby bottle food in Arba Minch, southern Ethiopia.ObjectiveTo evaluate the bacteriological quality and prevalence of foodborne pathogens in baby bottle food and to identify associated factors among bottle-fed babies attending three government health institutions in Arba Minch, southern Ethiopia.MethodsA cross-sectional study was conducted between February 24 and March 30, 2022. A total of 220 food samples, comprising four types prepared with different sources of materials, were collected from systematically selected bottle-fed babies attending health facilities. The data on sociodemographic characteristics, food hygiene, and handling practices were solicited by face-to-face interview using a semi-structured questionnaire. Food samples (10 mL) were quantitatively analyzed for total viable counts (TVC) and total coliform count (TCC) and qualitatively for the presence of common foodborne bacterial pathogens. Data were analyzed using SPSS; ANOVA and multiple linear regression analyses were done to identify factors influencing microbial counts.ResultsResults revealed that the means and standard deviations of TVC and TCC were 5.3 ± 2.3 log10 colony forming units (CFU)/mL and 4.1 ± 2.6 log10 CFU/mL, respectively. Of the various food samples analyzed, 57.3 and 60.5% had a TVC and TCC above the maximum acceptable limits, respectively. The result of the ANOVA showed that there was a significant difference in the mean score of TCV and TCC among the four types of food samples (p < 0.001). Enterobacteriaceae were found in the majority of positive food samples (79.13%), followed by Gram-positive cocci (20.8%). Salmonella spp., diarrheagenic Escherichia coli, and Staphylococcus aureus were the common foodborne pathogens detected in 8.6% of tested foods. The regression result revealed that the type of baby food, hand washing practices of mothers or caregivers, and sterilizing and disinfecting procedures of feeding bottles are independent determinants of bacterial contamination (p < 0.001).ConclusionThe high microbial load and the presence of potential foodborne bacterial pathogens in the bottle food samples analyzed indicate unsanitary practices and the potential risk of exposure to foodborne pathogens in bottle-fed babies. Thus, interventions such as educating parents about proper hygiene practices, sterilizing feeding bottles and limiting bottle feeding practices are critical to reducing the risk of foodborne to bottle-fed infants.

Emergence of colistin resistance and characterization of antimicrobial resistance and virulence factors of Aeromonas hydrophila, Salmonella spp., and Vibrio cholerae isolated from hybrid red tilapia cage culture.

Tilapia is a primary aquaculture fish in Thailand, but little is known about the occurrence of antimicrobial resistance (AMR) in Aeromonas hydrophila, Salmonella spp., and Vibrio cholerae colonizing healthy tilapia intended for human consumption and the co-occurrence of these AMR bacteria in the cultivation water. This study determined the phenotype and genotype of AMR, extended-spectrum β-lactamase (ESBL) production, and virulence factors of A. hydrophila, Salmonella spp., and V. cholerae isolated from hybrid red tilapia and cultivation water in Thailand. Standard culture methods such as USFDA's BAM or ISO procedures were used for the original isolation, with all isolates confirmed by biochemical tests, serotyping, and species-specific gene detection based on PCR. A total of 278 isolates consisting of 15 A. hydrophila, 188 Salmonella spp., and 75 V. cholerae isolates were retrieved from a previous study. All isolates of A. hydrophila and Salmonella isolates were resistance to at least one antimicrobial, with 26.7% and 72.3% of the isolates being multidrug resistant (MDR), respectively. All A. hydrophila isolates were resistant to ampicillin (100%), followed by oxytetracycline (26.7%), tetracycline (26.7%), trimethoprim (26.7%), and oxolinic acid (20.0%). The predominant resistance genes in A. hydrophila were mcr-3 (20.0%), followed by 13.3% of isolates having floR, qnrS, sul1, sul2, and dfrA1. Salmonella isolates also exhibited a high prevalence of resistance to ampicillin (79.3%), oxolinic acid (75.5%), oxytetracycline (71.8%), chloramphenicol (62.8%), and florfenicol (55.3%). The most common resistance genes in these Salmonella isolates were qnrS (65.4%), tetA (64.9%), bla TEM (63.8%), and floR (55.9%). All V. cholerae isolates were susceptible to all antimicrobials tested, while the most common resistance gene was sul1 (12.0%). One isolate of A. hydrophila was positive for int1, while all isolates of Salmonella and V. cholerae isolates were negative for integrons and int SXT. None of the bacterial isolates in this study were producing ESBL. The occurrence of mcr-3 (20.0%) in these isolates from tilapia aquaculture may signify a serious occupational and consumer health risk given that colistin is a last resort antimicrobial for treatment of Gram-negative bacteria infections. Findings from this study on AMR bacteria in hybrid red tilapia suggest that aquaculture as practiced in Thailand can select for ubiquitous AMR pathogens, mobile genetic elements, and an emerging reservoir of mcr and colistin-resistant bacteria. Resistant and pathogenic bacteria, such as resistance to ampicillin and tetracycline, or MDR Salmonella circulating in aquaculture, together highlight the public health concerns and foodborne risks of zoonotic pathogens in humans from cultured freshwater fish.

A glance into traditional pig slaughtering practices in Vietnam and opportunities for zoonotic disease prevention

IntroductionAfrican swine fever in Vietnam is contributing to existing concerns over zoonotic disease transmission from sick pigs to humans. While slaughterhouses are key sites of occupational hazards to workers and contamination of meat, the specific slaughtering practices contributing to zoonotic occupational and foodborne disease risks remain under-researched. Our objective is to identify and characterize aspects of pig slaughtering processes that contribute to such risks.MethodsWe draw on qualitative observations, photos, and videos from three mobile slaughterhouses and seven abattoirs in Hung Yen, Vietnam.ResultsBased on our analysis, areas likely leading to zoonotic disease risks include slaughtering procedures, personal hygiene of workers, equipment sanitation, and facility sanitation. Within the small-scale swine industry, slaughtering practices are long-standing and difficult to change.ConclusionOur study underscores the importance of hygiene training of workers, improvements to equipment and facilities, and awareness-building activities targeting consumers to reduce the burden of zoonotic disease risks in small-scale pig slaughter settings.

Salmonella Risk Assessment in Poultry Meat from Farm to Consumer in Korea.

This study predicted Salmonella outbreak risk from eating cooked poultry in various methods. The incidence of Salmonella in poultry meat and the environment from farm to home for consumption was investigated. To develop the predictive models, Salmonella growth data were collected at 4-25 °C during storage and fitted with the Baranyi model. The effects of cooking on cell counts in poultry meat were investigated. Temperature, duration, and consumption patterns were all searched. A simulation in @Risk was run using these data to estimate the probability of foodborne Salmonella disease. In farm, Salmonella was detected from only fecal samples (8.5%; 56/660). In slaughterhouses, Salmonella was detected from feces 16.0% (38/237) for chicken and 19.5% (82/420) for duck) and from carcasses of each step (scalding, defeathering, and chilling) by cross contamination. In chicken (n = 270) and duck (n = 205), Salmonella was detected in 5 chicken (1.9%) and 16 duck meat samples (7.8%). Salmonella contamination levels were initially estimated to be -3.1 Log CFU/g and -2.5 Log CFU/g, respectively. With R2 values between 0.862 and 0.924, the predictive models were suitable for describing the fate of Salmonella in poultry meat with of 0.862 and 0.924. The Salmonella was not detected when poultry meat cooks completely. However, if poultry meat contaminated with Salmonella were cooked incompletely, Salmonella remained on the food surface. The risk of foodborne Salmonella disease from poultry consumption after cooking was 3.0 × 10-10/person/day and 8.8 × 10-11/person/day in South Korea, indicating a low risk.

Risk assessment of enteric viruses along the food chain and in the population.

Food-borne microbial illness contributes up to one third of global disease burden. The largest category of food-borne illness is gastroenteritis, the majority of which is caused by enteric viruses. Viruses like these are transmitted to food either by waste-contaminated waters, or by handling and transfer during processing. An important tool for reducing or controlling food-borne microbial risk is risk analysis. This framework has been adopted globally to manage risks associated with microbial contamination in food. Several hundred microbial risk assessments (MRAs) have been published by different national and international organisations, for different food-hazard combinations. The use of MRAs in controlling and understanding virus risk has, to date, been limited, compared with the efforts made on bacterial pathogens. Given the large disease burden that viruses are responsible for, this disparity should be addressed. The main reasons for the relative lack of risk assessments are the difficulty in detecting and monitoring viruses compared with bacteria. This means less data on prevalence, concentration and inactivation, and allows viruses to remain silent contributors to global disease. There are also key conceptual differences between virus risk assessment and bacterial risk assessment. This project aimed to assess the current state of the art for food-borne virus risk assessment, then to progress the field further by using the data available to produce risk rankings and risk assessments. This was done by a combination of literature reviewing and various risk assessment tools. The result was an assessment of the overall evidence base in the literature, a semi-quantitative ranking comparison between the viruses and foods of most concern, and a survey of inactivation methods, leading to a quantitative ranking of the effectiveness of each in reducing and managing food-borne virus risk.

Influence of Season and Food Type on Bacterial and Entero-Toxigenic Prevalence of Staphylococcus aureus.

Staphylococcus (S.) aureus is a coagulase-positive pathogen of interest for human health and food safety in particular. It can survive in a wide environmental temperature range (7–48 °C, optimum 37 °C). Its enterotoxins are thermostable, which increases the risk of potential contamination in a variety of food products. Here we investigated the influence of seasonality and food type on bacterial count and presence of S. aureus enterotoxins. To do this, we analyzed 3604 food samples collected over a 5-year period (2016–2020). Ordinal logistic regression showed an influence of both seasonality and food type on the bacterial count. Regarding bacterial counts, winter was found to be the season with the highest risk, while with regards to enterotoxin production, the highest risk was found in autumn, specifically in October. The risk of contamination with S. aureus was greatest for dairy products. Our findings may inform food epidemiologists about foodborne illness prevention and risk to human health.

Research and application of foodborne disease risk prevention based on knowledge graph technology

Research and application of foodborne disease risk prevention based on knowledge graph technology

Identification of domestic reservoirs and common exposures in an emerging lineage of Shiga toxin-producing Escherichia coli O157:H7 in England: a genomic epidemiological analysis

The zoonotic pathogen Shiga toxin-producing Escherichia coli (STEC) O157:H7 emerged during the 1980s as a causative agent of foodborne outbreaks associated with haemorrhagic colitis and haemolytic uraemic syndrome, which can be fatal. We investigated the emerging lineage IIc that was causing outbreaks of STEC O157:H7, identified and quantified the domestic and non-domestic reservoirs, and quantified patient exposures across the population of England. In this genomic epidemiological analysis study, all human STEC O157:H7 lineage IIc (n=925) isolates cultured from faecal specimens submitted to the UK Health Security Agency between June 1, 2015, and Dec 31, 2020, from patients in England in the community or in hospital, were whole-genome sequenced and the genomic population structure was described. Explanatory variables were obtained from microbiological surveillance data and STEC Enhanced Surveillance Questionnaire responses. Ancestral-state reconstruction using patient travel information was used to define domestic and non-domestic clades and transmission dynamics. Exposures for patients infected with isolates from domestic clades were assessed using mixed-effects multinomial univariable and multivariable regression. Lineage IIc emerged 50 years ago, and subsequent clonal expansions have resolved into six major extant clades. We defined two English domestic clades that emerged during the past 30 years, and four non-domestic clades comprising isolates that infected or were transmitted to patients in England via international travel or the consumption or handling of imported food. Throughout the study period, non-domestic clades contributed approximately twice the number of infections as domestic clades did. Patients infected with domestic IIc clade strains reported more frequent exposure to fresh produce (raw vegetables p=0·012; prepackaged salad p=0·0009), contact with animals (cattle p=0·021), and visits to farms (p=0·0053) than patients infected with strains from other STEC O157:H7 lineages. A multivariable mixed-effects multinomial model confirmed that within the domestic clades, the major risk factors for infection were prepackaged salad (clade 2.3.3, relative risk ratio [RRR] 1·72, 95% CI 1·09-2·72; p=0·019) and visits to farms (clade 2.5.2, RRR 1·98, 1·12-3·52; p=0·020) as fixed effects. Local authority district as a random variable had a strong but variable effect for clades 2.3.3 and 2.5.2. Lineage IIc has emerged as the most prevalent lineage of STEC O157:H7 in England, with a sizeable domestic reservoir. Human infection is associated with the consumption of contaminated fresh produce and contact with domestic livestock. The collection of routine, detailed exposure data on patients who are infected, integrated with high-resolution microbiological typing, enables powerful reframing of our understanding of foodborne disease risk within a One Health context. National Institute for Health and Care Research Health and UK Health Security Agency.