Estimating foodborne gastroenteritis, Australia

Estimating the health burden of foodborne gastroenteritis caused by non-typhoidal Salmonella enterica and Vibrio parahaemolyticus in Zhejiang province, China

As acute gastrointestinal (AGI) disease patients only sometimes seek medical care or submit stool samples for testing, and laboratories cannot detect or identify the pathogen, most cases of foodborne gastroenteritis still need to be identified through public health monitoring. We conducted a population survey and sentinel hospital surveillance to determine the burden of foodborne gastroenteritis caused by non-typhoidal Salmonella enterica (NTS) and Vibrio parahaemolyticus infection, from July 2018 to June 2019 in Zhejiang province, China, and a model for calculating disease burden established. Using the burden of illness pyramid model, we estimated that there were 140.3 cases of NTS infection and 136.2 cases of V. parahaemolyticus infection. We estimated annual incidence per 100,000 population in Zhejiang province as 236 (95% confidence interval [CI] 208-267) and 206 (95% CI 155-232) cases for foodborne NTS and V. parahaemolyticus gastroenteritis, respectively. The results show that AGI caused by these two pathogens constitutes a substantial burden in the Zhejiang population. The health burden of AGI estimations caused by NTS and V. parahaemolyticus in this study can serve as a strategic framework to direct policy and intervention.

An integrated FoodNet in North East India: fostering one health approach to fortify public health

BACKGROUND

Food safety is a critical factor in promoting public health and nutrition, especially in developing countries like India, which experience several foodborne disease outbreaks, often with multidrug-resistant pathogens. Therefore, implementing regular surveillance of enteric pathogens in the human-animal-environment interface is necessary to reduce the disease burden in the country.

OBJECTIVE

To establish a network of laboratories for the identification of major food and waterborne pathogens prevailing in the northeast region of India through integrated surveillance of animal, food, human, and environment and investigate the antimicrobial susceptibility pattern of the pathogens of public health significance.

METHODS

The Indian Council of Medical Research (ICMR) has identified FoodNet laboratories; based on their geographical location, inclination to undertake the study, preparedness, proficiency, and adherence to quality assurance procedures, through an 8-step process to systematically expand to cover the Northeastern Region (NER) with comprehensive diagnostic capacities for foodborne pathogens and diarrhea outbreak investigations. Network initiated in the NER given the unique food habits of the ethnic population.

FINDINGS

This surveillance network for foodborne enteric pathogens was established in Assam, Arunachal Pradesh, Tripura, and Sikkim, and expanded to other four states, i.e., Manipur, Mizoram, Meghalaya, and Nagaland, thereby covering the entire NER by including nine medical and three veterinary centers. All these centers are strengthened with periodic training, technical support, funding, capacity building, quality assurance, monitoring, centralized digital data management, and website development.

RESULTS

The ICMR-FoodNet will generate NER-specific data with close to real-time reporting of foodborne disease and outbreaks, and facilitate the updating of food safety management protocols, policy reforms, and public health outbreak response. During 2020-2023, 13,981 food samples were tested and the detection of enteric pathogens ranged from 3 to 4%. In clinical samples, the detection rate of the pathogens was high in the diarrheal stools (8.9%) when 3,107 samples were tested. Thirteen outbreaks were investigated during the study period.

CONCLUSION

Foodborne diseases and outbreaks are a neglected subject. Given the frequent outbreaks leading to the deaths of children, it is crucial to generate robust data through well-established surveillance networks so that a strong food safety policy can be developed for better public health.

Analysis of reservoir sources of Campylobacter isolates to free-range broilers in Denmark

Campylobacter is a common cause of food poisoning in many countries, with broilers being the main source. Organic and free-range broilers are more frequently Campylobacter-positive than conventionally raised broilers and may constitute a higher risk for human infections. Organic and free-range broilers may get exposed to Campylobacter from environmental reservoirs and livestock farms, but the relative importance of these sources is unknown. The aim of the study was to describe similarities and differences between the genetic diversity of the Campylobacter isolates collected from free-range/organic broilers with those isolated from conventional broilers and other animal hosts (cattle, pigs, and dogs) in Denmark to make inferences about the reservoir sources of Campylobacter to free-range broilers. The applied aggregated surveillance data consisted of sequenced Campylobacter isolates sampled in 2015 to 2017 and 2018 to 2021. The data included 1,102 isolates from free-range (n = 209), conventional broilers (n = 577), cattle (n = 261), pigs (n = 30), and dogs (n = 25). The isolates were cultivated from either fecal material (n = 434), food matrices (n = 569), or of nondisclosed origin (n = 99). Campylobacter jejuni (94.5%) dominated and subtyping analysis found 170 different sequence types (STs) grouped into 75 clonal complexes (CCs). The results suggest that CC-21 and CC-45 are the most frequent CCs found in broilers. The relationship between the CCs in the investigated sources showed that the different CCs were shared by most of the animals, but not pigs. The ST-profiles of free-range broilers were most similar to that of conventional broilers, dogs and cattle, in that order. The similarity was stronger between conventional broilers and cattle than between conventional and free-range broilers. The results suggest that cattle may be a plausible reservoir of C. jejuni for conventional and free-range broilers, and that conventional broilers are a possible source for free-range broilers or reflect a dominance of isolates adapted to the same host environment. Aggregated data provided valuable insight into the epidemiology of Campylobacter sources for free-range broilers, but time-limited sampling of isolates from different sources within a targeted area would hold a higher predictive value.

Control of Escherichia coli in Fresh-Cut Mixed Vegetables Using a Combination of Bacteriophage and Carvacrol

The continual emergence of antibiotic-resistant bacteria and the slow development of new antibiotics has driven the resurgent interest in the potential application of bacteriophages as antimicrobial agents in different medical and industrial sectors. In the present study, the potential of combining phage biocontrol and a natural plant compound (carvacrol) in controlling Escherichia coli on fresh-cut mixed vegetable was evaluated. Four coliphages, designated Escherichia phage SUT_E420, Escherichia phage SUT_E520, Escherichia phage SUT_E1520 and Escherichia phage SUT_E1620, were isolated from raw sewage. Biological characterization revealed that all four phages had a latent period of 20-30 min and a burst size ranging from 116 plaque-forming units (PFU)/colony forming units (CFU) to 441 PFU/CFU. The phages effectively inhibited the growth of respective host bacteria in vitro, especially when used at a high multiplicity of infection (MOI). Based on transmission electron microscopy analysis, all phages were classified as tailed phages in the class of Caudoviricetes. Additionally, next generation sequencing indicated that none of the selected coliphages contained genes encoding virulence or antimicrobial resistance factors, highlighting the suitability of isolated phages as biocontrol agents. When a phage cocktail (~109 PFU/mL) was applied alone onto fresh-cut mixed vegetables artificially contaminated with E. coli, no bacteria were recovered from treated samples on Day 0, followed by a gradual increase in the E. coli population after 24 h of incubation at 8 °C. On the other hand, no significant differences (p < 0.05) were observed between treated and non-treated samples in terms of E. coli viable counts when carvacrol at the minimum inhibitory concentration (MIC) of 6.25 μL/mL was applied alone. When a phage cocktail at an MOI of ~1000 and MIC carvacrol were applied in combination, no E. coli were recovered from treated samples on Day 0 and 1, followed by a slight increase in the E. coli population to approximately 1.2-1.3 log CFU/mL after 48 h of incubation at 8 °C. However, total elimination of E. coli was observed in samples treated with a phage cocktail at a higher MOI of ~2000 and carvacrol at MIC, with a reduction of approximately 4 log CFU/mL observed at the end of Day 3. The results obtained in this study highlight the potential of combined treatment involving phage biocontrol and carvacrol as a new alternative method to reduce E. coli contamination in minimally processed ready-to-eat foods.

Recent Progress in the Synergistic Bactericidal Effect of High Pressure and Temperature Processing in Fruits and Vegetables and Related Kinetics

BACKGROUND

Traditional thermal processing is a widely used method to ensure food safety. However, thermal processing leads to a significant decline in food quality, especially in the case of fruits and vegetables. To overcome this drawback, researchers are extensively exploring alternative non-thermal High-Pressure Processing (HPP) technology to ensure microbial safety and retaining the sensory and nutritional quality of food. However, HPP is unable to inactivate the spores of some pathogenic bacteria; thus, HPP in conjunction with moderate- and low-temperature is employed for inactivating the spores of harmful microorganisms. Scope and approach: In this paper, the inactivation effect of high-pressure and high-pressure thermal processing (HPTP) on harmful microorganisms in different food systems, along with the bactericidal kinetics model followed by HPP in certain food samples, have been reviewed. In addition, the effects of different factors such as microorganism species and growth stage, process parameters and pressurization mode, and food composition on microbial inactivation under the combined high-pressure and moderate/low-temperature treatment were discussed.

KEY FINDINGS AND CONCLUSIONS

The establishment of a reliable bactericidal kinetic model and accurate prediction of microbial inactivation will be helpful for industrial design, development, and optimization of safe HPP and HPTP treatment conditions.

Estimating the burden of foodborne gastroenteritis due to nontyphoidal Salmonella enterica, Shigella and Vibrio parahaemolyticus in China

To estimate the incidence of foodborne gastroenteritis caused by nontyphoidal Salmonella enterica, Shigella, and Vibrio parahaemolyticus in China, population surveys and sentinel hospital surveillance were implemented in six provinces from July 2010 to July 2011, and a multiplier calculation model for the burden of disease was constructed. The multiplier for salmonellosis and V. parahaemolyticus gastroenteritis was estimated at 4,137 [95% confidence interval (CI) 2,320–5,663], and for shigellosis at 4,356 (95% CI 2,443–5,963). Annual incidence per 100,000 population was estimated as 245 (95% CI 138–336), 67 (95% CI 38–92), and 806 (95% CI 452–1,103) for foodborne salmonellosis, shigellosis, and V. parahaemolyticus gastroenteritis, respectively, indicating that foodborne infection caused by these three pathogens constitutes an important burden to the Chinese healthcare system. Continuous implementation of active surveillance of foodborne diseases, combined with multiplier models to estimate disease burden, makes it possible for us to better understand food safety status in China.

Global Burden and Trends of Norovirus-Associated Diseases From 1990 to 2019: An Observational Trend Study

Introduction

As an important pathogen causing diarrheal diseases, the burden and change in the death rate of norovirus-associated diseases (NADs) globally are still unknown.

Methods

Based on global disease burden data from 1990 to 2019, we analyzed the age-standardized death rate (ASDR) of NADs by age, region, country, and Socio-Demographic Index (SDI) level. The discrete Poisson model was applied in the analysis of NADs' spatiotemporal aggregation, the Joinpoint regression model to analyze the trend of death burden of NADs over 30 years, and a generalized linear model to identify the risk factors for the death rate from NADs.

Results

The ASDR of NADs significantly decreased by a factor of approximately 2.7 times, from 5.02 (95% CI: 1.1, 11.34) in 1990 to 1.86 (95% CI: 0.36, 4.16) in 2019 [average annual percent change (AAPC) = −3.43, 95% CI: −3.56, −3.29]. The death burden of NADs in 2019 was still highest in African regions despite a great decline in recent decades. However, the ASDR in high SDI countries presented an uptrend [0.12 (95% CI: 0.03, 0.26) in 1990 and 0.24 (95% CI: 0.03, 0.53) in 2019, AAPC = 2.52, 95% CI: 2.02–3.03], mainly observed in the elderly over 70 years old. Compared to children under 5 years old, the 2019 death rate of elderly individuals over 80 years old was much higher in high SDI countries. The generalized linear model showed that factors of the number of physicians (RR = 0.67), the proportions of children under 14 years old (RR = 1.21), elderly individuals over 65 years old (RR = 1.13), educational level (RR = 1.03) and urbanization proportion (RR = 1.01) influenced the ASDR of NADs.

Conclusions

The death burden of NADs has remained high in developing regions over the last three decades and has increased among the elderly in countries with high SDI levels, even though the global trend in NAD-associated deaths has decreased significantly in the past three decades. More effective public health policies against NADs need to be implemented in high SDI regions and for the elderly.

Enteric viruses in food safety: New threats for an old problem

Foodborne diseases are one of the most serious concerns in public health. It is estimated that around 600 million cases of gastroenteritis occur worldwide each year. At present, more than 200 food-borne diseases are known, which can cause from mild gastroenteritis to syndromes with a fatal outcome, with the added possibility of chronic complications. One of the major etiological agents in foodborne diseases are the food and waterborne viruses, which are attracting a great deal of attention to researchers, food hygienists and policy makers. Several aspects differentiate these pathogens from foodborne pathogenic bacteria: their high capacity for infection and preservation in food environments, and their difficulty for a correct and sensitive detection. In recent years, different initiatives have been carried out to prioritize research in the area of viruses in food, prioritizing different aspects of their detection, epidemiology and control. There is clear evidence that the existing data on their prevalence may be underestimated due to the lack of robust methods for their sensitive detection. It is also necessary to know exactly what the incidence is in the different stages of the food production chain, and particularly in that which is dedicated to the transformation of products of animal origin. Finally, it is also necessary to calibrate the current disinfection procedures in the food industry in order to reliably establish a quantitative evaluation of the viral risk in food.

A norovirus gastroenteritis outbreak in an Australian child-care center: A household-level analysis

There is a large burden of norovirus disease in child-care centers in Australia and around the world. Despite the ubiquity of norovirus outbreaks in child-care centers, little is known about the extent of this burden within the child-care center and the surrounding household clusters. Therefore, we performed an in-depth analysis of a gastroenteritis outbreak to examine the patterns of transmissions, household attack rates and the basic reproduction number (R₀) for Norovirus in a child-care facility. We used data from parental interviews of suspected cases sent home with gastroenteritis at a child-care center between 24^th of August and 18^th of September 2020. A total of 52 persons in 19 household clusters were symptomatic in this outbreak investigation. Of all transmissions, 23 (46.9%) occurred in the child-care center, the rest occurring in households. We found a household attack rate of 36.5% (95% CI 27.3, 47.1%). Serial intervals were estimated as mean 2.5 ± SD1.45 days. The R₀, using time-dependent methods during the growth phase of the outbreak (days 2 to 8) was 2.4 (95% CI 1.50, 3.50). The count of affected persons of a child-care center norovirus outbreak is approximately double the count of the total symptomatic staff and attending children. In the study setting, each symptomatic child-care attendee likely infected one other child-care attendee or staff and just over one household contact on average.

Recommended Practices to Eliminate Campylobacter from Live Birds and Chicken Meat in Japan

Campylobacter food poisoning is one of the major bacterial foodborne diseases resulting in numerous outbreaks worldwide. Particularly in Japan, one-fourth of the total food poisoning is caused by Campylobacter jejuni/coli. Raw and/or undercooked poultry meat and meat products are known as the main cause of campylobacteriosis. Consequently, effective and immediate actions are needed to eliminate or at least reduce campylobacteriosis. This study aimed at examining the Japanese food regulation system, comparing it with those in the USA and Australia, and making necessary recommendations for a better control of campylobacteriosis in Japan. The study was conducted by a thorough investigation of published literatures, governmental documents, statistical and epidemiological data and public information. The results led to recommendations that the Japanese food regulation authority should consider the following suggestions in order to control campylobacteriosis: 1) assess the Campylobacter safety at the end of processing stage of chicken supply chain based on risk assessment using quantitative/qualitative baseline data collected over Japan, 2) establish a national Campylobacter strategy, including specific campylobacteriosis reduction goals and criteria, and 3) provide the small food business operators with sufficient training and support to implement a Hazard Analysis Critical Control Points (HACCP) as an obligatory food safety requirement. It is acknowledged that it would be difficult to apply foreign regulations directly to Japanese food regulation system due to differences in food culture, regulation, industry structure, and data collection systems. Thus, flexible application is required. Finding and conducting effective Campylobacter control measures can decrease contaminated live birds and chicken meat in Japan, home to a unique food culture of eating raw and/or undercooked chicken meat called Torisashi such as sashimi, tataki and yubiki chicken. Consequently, potentially available research data may be instrumental in finding solutions for reducing campylobacteriosis. Eliminating Campylobacter food poisoning cases in Japan will be a significant achievement in ensuring Japanese and global food safety.

Estimating the Number of Illnesses Caused by Agents Transmitted Commonly Through Food: A Scoping Review

Estimates of the overall human health impact of agents transmitted commonly through food complement surveillance and help guide food safety interventions and regulatory initiatives. The purpose of this scoping review was to summarize the methods and reporting practices used in studies that estimate the total number of illnesses caused by these agents. We identified and included 43 studies published from January 1, 1995, to December 31, 2019, by searching PubMed and screening selected articles for other relevant publications. Selected articles presented original estimates of the number of illnesses caused by ≥1 agent transmitted commonly through food. The number of agents (species or subspecies for pathogens) included in each study ranged from 1 to 31 (median: 4.5; mean: 9.2). Of the 40 agents assessed across the 43 studies, the most common agent was Salmonella (36; 84% of studies), followed by Campylobacter (33; 77%), Shiga toxin-producing Escherichia coli (25; 58%), and norovirus (20; 47%). Investigators used a variety of data sources and methods that could be grouped into four distinct estimation approaches-direct, surveillance data scaled-up, syndrome or population scaled-down, and inferred. Based on our review, we propose four recommendations to improve the interpretability, comparability, and reproducibility of studies that estimate the number of illnesses caused by agents transmitted commonly through food. These include providing an assessment of statistical and nonstatistical uncertainty, providing a ranking of estimates by agent, including uncertainties; describing the rationale used to select agents and data sources; and publishing raw data and models, along with clear, detailed methods. These recommendations could lead to better decision-making about food safety policies. Although these recommendations have been made in the context of illness estimation for agents transmitted commonly through food, they also apply to estimates of other health outcomes and conditions.

Prescribing Antimicrobial Drugs for Acute Gastroenteritis, Primary Care, Australia, 2013-2018

Prescriptions for 6.8% of cases suggests a need for greater antimicrobial stewardship.

During 2013–2018, antimicrobial drugs were prescribed for 6.8% of cases of acute gastroenteritis encountered in general practice in Australia, including 35.7% of Salmonella infections and 54.1% of Campylobacter infections. During that time, prescriptions for acute gastroenteritis decreased by 2.0%. Managing infectious gastroenteritis in general practice will require greater antimicrobial stewardship.

Prevalence and risk of staphylococcal and coliform carcass contamination of chickens slaughtered in the informal market in Gauteng, South Africa

Purpose

The primary objective was to determine the prevalence of indicator microorganisms [Staphylococcus aureus, non-S. aureus staphylococci (NSAS), coliforms and aerobic bacteria] for contamination of chicken carcasses, carcass drip and rinse water from the informal chicken market in Gauteng, South Africa.

Design/methodology/approach

Chicken swabs, chicken drips and rinse waters were collected from 151 chickens from 47 random outlets. Pre-tested questionnaires were administered to capture the risk factors for bacterial contamination. Standard microbiological procedures were conducted for isolation and enumeration of target bacteria.

Findings

NSAS (64% and 41%) and S. aureus (12% and 31%) were prevalent on carcasses and in carcass drip respectively. Coliforms (62%) and aerobic bacteria (85%) were detected in rinse water. Significant risk factors for contamination of carcasses with NSAS, S. aureus and coliform organisms were: evisceration of chickens on the same location used for sale, cleaning of display counter with dirty clothes/wipes, holding of differently sourced chickens in the same cage prior to slaughter, not cleaning the display table/counter and hands at all, washing knives in rinse water, high turnover of daily slaughter and length of time to display chickens.

Research limitations/implications

The limitations of this research were the limited geographical coverage and small sample size.

Practical implications

The isolation of these indicator microorganisms suggests the potential presence of other chicken-borne pathogens not tested for in the study.

Social implications

The findings serve to inform policy on public health and street-vended food and can guide control on good sanitary practices.

Originality/value

This is the first comprehensive report on ready to eat chickens from the informal markets in Gauteng, South Africa.

Community-level burden of acute diarrhoeal illness in the first 2 years of life in Brisbane, Australia: A birth cohort study

AIM

This study sought to describe the burden of acute diarrhoeal illness (ADI) in an Australian subtropical urban setting following rotavirus vaccine introduction and to investigate the associations between child/family characteristics and ADI.

METHODS

Parents of 154 children from the Observational Research in Childhood Infectious Diseases birth cohort provided daily symptom and health-care data until the age of 2 years.

RESULTS

The incidence rate of ADI was 1.07 per child-year (95% confidence interval: 0.94-1.21). The median length of episode duration was 3 days (25th-75th percentiles: 1-6). The incidence rate was significantly higher in the first month of life and between 6 and 17 months of age compared with 18-23 months, also for children with siblings and in formal childcare. Overall, 49% of ADI episodes led to health-care visits.

CONCLUSIONS

Despite a successful rotavirus vaccine programme, ADI still results in a substantial disease burden affecting young Australian children and their families.

Comparison of heat-illness associations estimated with different temperature metrics in the Australian Capital Territory, 2006-2016

While the associations of heat with health outcomes is well researched, there is less consensus on the measures used to define heat exposure and the short-term and delayed impacts of different temperature metrics on health outcomes. We investigate the nonlinear and short-term relationship of three temperature metrics and reported incidence of three gastrointestinal illnesses: salmonellosis, campylobacteriosis and cryptosporidiosis in the Australian Capital Territory (ACT). We also examine the nonlinear association of these illnesses with extreme heat (5th, 75th, 90th percentile of all heat measures). Generalized linear models with Poisson regression accounting for overdispersion, seasonal and long-term trend, weekly number of outbreaks and rainfall were developed for mean and maximum weekly temperature and the heat stress index (EHI_accl). Bacterial illnesses (salmonellosis and campylobacteriosis) showed an overall positive association with extreme heat (75th and 90th percentile of all three heat measures) and an inverse association with low temperature (5th percentile). The shape of the exposure-response curve across a range of temperatures and the lagged effects varied for each disease. Modelling the short-term and delayed effects of heat using different metrics across a range of illnesses can help identify the most appropriate measure to inform local public health intervention planning for heat-related emergencies.

The human health burden of non-typhoidal Salmonella enterica and Vibrio parahaemolyticus foodborne gastroenteritis in Shanghai, east China

Information on the burden of disease due to foodborne pathogens in China is quite limited. To understand the incidence of foodborne gastroenteritis due to non-typhoidal Salmonella enterica and Vibrio parahaemolyticus, population survey and sentinel hospital surveillance were conducted during July 2010 to June 2011 in Shanghai, east China, and a model for calculating disease burden was established. The multiplier for gastroenteritis caused by these pathogens was estimated at 59 [95% confidence interval (CI) 30–102]. Annual incidence per 100,000 population in Shanghai was estimated as 48 (95% CI 24–83) and 183 (95% CI 93–317) cases for foodborne non-typhoidal salmonellosis and V. parahaemolyticus gastroenteritis, respectively, illustrating that bacterial gastroenteritis due to these two pathogens poses a substantial health burden. There is a significant difference between our simulated incidence and the data actually reported for foodborne diseases, indicating significant underreporting and underdiagnosis of non-typhoidal S. enterica and V. parahaemolyticus gastroenteritis in the surveillance area. The present research demonstrates basic situation of the health burden caused by major foodborne pathogens in the surveillance area. Enhanced laboratory-based sentinel hospital surveillance is one of the effective ways to monitor food safety in east China.

Discovery and characterisation of circular bacteriocin plantacyclin B21AG from Lactiplantibacillus plantarum B21

Lactiplantibacillus plantarum B21 isolated from Vietnamese sausage (nem chua) has previously displayed broad antimicrobial activity against Gram-positive bacteria including foodborne pathogens Listeria monocytogenes and Clostridium perfringens. This study successfully identified the antimicrobial agent as plantacyclin B21AG, a 5668 Da circular bacteriocin demonstrating high thermostability, resistance to a wide range of pH, proteolytic resistance and temporal stability. We report a reverse genetics approach to identify and characterise plantacyclin B21AG from first principles. The bacteriocin was purified from culture supernatant by a three-step process consisting of concentration, n-butanol extraction and cation exchange chromatography. A de novo peptide sequencing using LC-MS/MS techniques identified two putative peptide fragments which were mapped to the genome sequence of L. plantarum B21. This revealed an ORF corresponding to a putative circular bacteriocin with a 33-amino acid leader peptide and a 58-amino acid mature peptide encoded on a native plasmid pB21AG01. The bacteriocin is shown to be a small cationic predominantly α-helical protein (69%). The corresponding gene cluster, consisted of seven genes associated with post-translational circularisation, immunity and secretion. Whilst plantacyclin B21AG is 86% identical to the newly published plantaricyclin A it is more highly cationic having a net charge of +3 due to an additional basic residue in the putative membrane interaction region. This and other substitutions may well go some way to explaining functional differences. The robust nature of plantacyclin B21AG, its antimicrobial activity and associated machinery for cyclisation make it an interesting biotechnological target for development, both as a food-safe antimicrobial or potentially a platform technology for recombinant protein circularisation.

Human campylobacteriosis related to cross-contamination during handling of raw chicken meat: Application of quantitative risk assessment to guide intervention scenarios analysis in the Australian context

Quantitative Microbiological Risk Assessment (QMRA) is a methodology used to organize and analyze scientific information to both estimate the probability and severity of an adverse event as well as prioritize efforts to reduce the risk of foodborne pathogens. No QMRA efforts have been applied to Campylobacter in the Australian chicken meat sector. Hence, we present a QMRA model of human campylobacteriosis related to the occurrence of cross-contamination while handling raw chicken meat in Western Australia (WA). This work fills a gap in Campylobacter risk characterization in Australia and enables benchmarking against risk assessments undertaken in other countries. The model predicted the average probability of the occurrence of illness per serving of salad that became cross-contaminated from being handled following the handling of fresh chicken meat as 7.0 × 10^-4 (90% Confidence Interval [CI] ± 4.7 × 10^-5). The risk assessment model was utilized to estimate the likely impact of intervention scenarios on the predicted probability of illness (campylobacteriosis) per serving. Predicted relative risk reductions following changes in the retail prevalence of Campylobacter were proportional to the percentage desired in the reduction scenario; a target that is aiming to reduce the current baseline prevalence of Campylobacter in retail chicken by 30% is predicted to yield approximately 30% relative risk reduction. A simulated one-log reduction in the mean concentration of Campylobacter is anticipated to generate approximately 20% relative risk reductions. Relative risk reduction induced by a one-log decrease in the mean was equally achieved when the tail of the input distribution was affected-that is, by a change (one-log reduction) in the standard deviation of the baseline Campylobacter concentration. A scenario assuming a 5% point decrease in baseline probability of cross-contamination at the consumer phase would yield relative risk reductions of 14%, which is as effective as the impact of a strategic target of 10% reduction in the retail prevalence of Campylobacter. In conclusion, the present model simulates the probability of illness predicted for an average individual who consumes salad that has been cross-contaminated with Campylobacter from retail chicken meat in WA. Despite some uncertainties, this is the first attempt to utilize the QMRA approach as a scientific basis to guide risk managers toward implementing strategies to reduce the risk of human campylobacteriosis in an Australian context.

Estimate of the annual burden of foodborne illness in nondeployed active duty US Army Service Members: five major pathogens, 2010-2015

In this study, we estimate the burden of foodborne illness (FBI) caused by five major pathogens among nondeployed US Army service members. The US Army is a unique population that is globally distributed, has its own food procurement system and a food protection system dedicated to the prevention of both unintentional and intentional contamination of food. To our knowledge, the burden of FBI caused by specific pathogens among the US Army population has not been determined. We used data from a 2015 US Army population survey, a 2015 US Army laboratory survey and data from FoodNet to create inputs for two model structures. Model type 1 scaled up case counts of Campylobacter jejuni, Shigella spp., Salmonella enterica non-typhoidal and STEC non-O157 ascertained from the Disease Reporting System internet database from 2010 to 2015. Model type 2 scaled down cases of self-reported acute gastrointestinal illness (AGI) to estimate the annual burden of Norovirus illness. We estimate that these five pathogens caused 45 600 (5%-95% range, 30 300-64 000) annual illnesses among nondeployed active duty US Army Service members. Of these pathogens, Norovirus, Campylobacter jejuni and Salmonella enterica non-typhoidal were responsible for the most illness. There is a tremendous burden of AGI and FBI caused by five major pathogens among US Army Soldiers, which can have a tremendous impact on readiness of the force. The US Army has a robust food protection program in place, but without a specific active FBI surveillance system across the Department of Defence, we will never have the ability to measure the effectiveness of modern, targeted, interventions aimed at the reduction of specific foodborne pathogens.

The Effect of Sanitizers on Microbial Levels of Chicken Meat Collected from Commercial Processing Plants

Chicken meat can potentially become contaminated with bacteria at the processing plant. In Australia, there is currently a lack of knowledge on the parameters and indications of use of non-chlorine based treatments in the chicken meat processing plants. Chlorine is widely used as a sanitizer in Australian chicken meat processing plants but due to occupational health and safety concerns and consumer perception, there is a need to identify alternative sanitizers. This study aimed to assess the efficacy of four different sanitizers in reducing the microbial load from naturally contaminated chicken meat carcasses collected from the processing plants in South Australia. There was a significant variation in a load of Campylobacter and total viable count (TVC) between samples collected from two different processing plants and within carcass batches collected from the same plant that was tested during the study. All sanitizers generally reduced the load of Campylobacter on chicken meat carcasses. Treatment with acidified sodium chlorite significantly reduced the level of Salmonella enterica serovars at all temperatures tested during this study. These findings are helpful to the industry for selection of the appropriate sanitizers. Findings are also useful for the regulatory authorities in Australia for providing approval for the use of sanitizers.

Pathways of healthcare and antibiotics use following reported gastrointestinal illness: a cross-sectional study in rural Anhui, China

OBJECTIVE

To document the factors, and their pathways, that influence healthcare and antibiotics use following reported gastrointestinal illnesses in Anhui province, China.

STUDY DESIGN

This study uses cross-sectional design, descriptive statistical analysis, pathway mapping and multivariate logistic regression modelling.

SETTING

Households in 12 villages in Anhui province, China.

PARTICIPANTS

A total of 3659 residents who: (1) held a registered rural residence and were actually living in the sampled villages when this study was conducted; (2) were aged 18 years and older and (3) were willing to participate and able to answer the survey questions.

OUTCOME MEASURES

Planned and measured variables included the occurrence of gastrointestinal illness, professional care seeking and antibiotic use due to the illness and factors influencing these measures.

RESULTS

Of the 3659 informants, 29.0% reported gastrointestinal illness episodes in the past year. Of these episodes, 50.2% led to professional care seeking and 65.4% of antibiotic use. Multivariate logistic modelling identifies that: (1) reported gastrointestinal illnesses were more frequent in north compared with middle (OR 0.569, 95% CI 0.472 to 0.686) and south (OR 0.588, 95% CI 0.492 to 0.702) Anhui, and were positively associated with age (B=0.123, p<0.05), knowledge concerning (B=0.248, p<0.05) and practice of (B=0.184, p<0.05) prevention; (2) seeking professional care and antibiotic use following the illness was linked to the severity of symptoms and geographical locations, rather than to specific pathogenic features.

CONCLUSIONS

Reported gastrointestinal illnesses are quite prevalent in the sample population and a large proportion of these have resulted in professional care and antibiotics use. The factors associated with the reported illnesses and pathways of healthcare and antibiotic use, as identified in this study, should inform future research and intervention efforts.

Descriptive Study of Foodborne Disease Using Case Monitoring Data in Shandong Province, China, 2016-2017

BACKGROUND

In order to generate data on the burden of foodborne diseases in Shandong Province, we aimed to use the case monitoring data of foodborne diseases from 2016 to 2017 to estimate.

METHODS

Data were obtained from the foodborne disease surveillance reporting system with dates of onset from Jan 1, 2016, to Dec 31, 2017, in Shandong, China.

RESULTS

The places of food exposure were categorized by settings as follows: private home, catering facility, collective canteens, retail markets, rural banquets and other. Exposed food is divided into 23 categories. Overall incidence rate and proportions by exposure categories, age, and sex-specific incidence rates were calculated and sex proportions compared. Approximately 75.00% of cases who had at least one exposure settings were in private homes. The most frequently reported exposed food was a variety of food (meaning more than two kinds of food). The two-year average incidence rate was 75.78/100,000, sex-specific incidence rate was much higher for females compared to males (78.23 vs. 74.69 cases per 100,000 population). An age-specific trend was observed in the cases reported (Chi-Square for linear trend, χ²=4.39, P=0.036<0.05).

CONCLUSION

A preliminary estimate of 14 million cases of foodborne diseases in Shandong province each year. Future studies should focus on cross-sectional and cohort studies to facilitate the assessment of the distribution and burden of foodborne disease of the population in Shandong. Considering strengthening the burden of foodborne diseases in foodborne disease surveillance is also a feasible way.

The prevalence of Campylobacter spp. in vegetables, fruits, and fresh produce: a systematic review and meta-analysis

There are a number of reports indicating correlation between outbreaks of campylobacteriosis and the consumption of raw vegetables. This study is a meta-analysis on the prevalence of Campylobacter in fresh vegetables and fruits without any location limitation, which was performed through a documented review of the available resources. Relevant literature was reviewed by trained reviewers, who examined the results for the inclusion of articles in the meta-analysis. The prevalence of Campylobacter in raw vegetables, the sample source, the Campylobacter species, and the method of detection were extracted. The prevalence of Campylobacter in vegetables, fruits, and fresh produce were estimated to be 0.53%. Analysis of the various sample groups initially showed that the bean and sprouts group was the vegetable with the highest prevalence of Campylobacter (11.08%). The rate of contamination was higher when both the molecular and conventional methods were employed. The highest prevalence of Campylobacter was found in Asia (33.4%). Despite the low prevalence, consumption of raw vegetables is inherently risky because no treatment is used to inactivate the pathogens. Therefore, proper sanitation methods are recommended to treat the raw products.

Incidence of acute diarrheal illness in Chinese communities: a meta-analysis

BACKGROUND

Acute diarrheal illness (ADI) is an important public health problem worldwide. We estimated the morbidity, distribution, and burden of self-reported ADI in China over the last three decades.

METHODS

We used the keywords "diarrhea and morbidity" to identify studies published in Chinese by searching CNKI, WANFANG, Chongqing VIP, and SinoMed. Studies published in English were identified using the keywords "diarrhea, morbidity, and China" to search Pubmed/Medline, Embase, and Cochrane Library Data. All articles published before Dec 31, 2014 were included in the search. Data were extracted and the pooled 2-week incidence rate of ADI was calculated using the fixed-effects or random-effects model according to statistical testing for homogeneity. The incidences of each subgroup (organized by age, location, study period) were also calculated. Publication bias was examined using Begg's test. Data manipulation and statistical analyses were undertaken using R-2.15.1 software.

RESULTS

We estimated that the pooled 2-week prevalence of ADI in China was 2.04% (95% CI: 1.48-2.79) and that the corresponding incidence rate was 0.53 (95% CI: 0.38-0.73) episodes per person-year. The ADI rate was highest among children aged < 5 years (1.43 episodes per person-year), and it was slightly higher in males than in females (0.58 vs 0.52 episodes per person-year). From 1980 to 2012, there was a significant decrease in the incidence of ADI, from 0.82 to 0.48 episodes per person-year, but the ADI incidence was consistent over the last two decades. Additionally, the incidence of ADI was higher in rural areas and in west China and peaked in the summer months.

CONCLUSIONS

The current study indicates that ADI caused a substantial disease burden in China in the last 30 years, especially in rural areas and west China, where sanitation conditions were relatively poor. These findings highlight the importance of further investigation of the specific causes of and effective preventive measures for ADI.

Monitoring the Results of Foodborne Diseases in Sentinel Hospitals in Wenzhou City, China from 2014 to 2015

BACKGROUND

To investigate the epidemiologic distribution of foodborne diseases in Wenzhou City from 2014-2015, we analyzed the characteristics and main pathogens of foodborne disease outbreaks to provide a reference for the prevention, control, and early warning of foodborne diseases.

METHODS

A total of 9139 patients with foodborne diseases were included in the database of active monitoring from sentinel hospitals in Wenzhou City, China. Salmonella, Shigella, Vibrio parahaemolyticus, enteropathogenic Escherichia coli, and norovirus in the stool samples collected from patients with foodborne diseases were detected according to national standards.

RESULTS

There were 82 cases of Salmonella, 6 cases of Shigella, 393 cases of V. parahaemolyticus, 9 cases of diarrhoeagenic E. coli, and 143 cases of norovirus in the 9139 stool and anal swab samples, for a total detection rate of 6.98%. The peak season in which foodborne diseases occurred was from Jun-Oct. The high-risk populations were the 0-5, 16-25, 26-35, 35-45, and 46-55 yr age groups. Aquatic products accounted for the greatest proportion of suspected food, followed by meat, poultry, fruits, and vegetables.

CONCLUSION

V. parahaemolyticus was the main pathogen of foodborne diseases in the Wenzhou urban area; Salmonella and norovirus were also foodborne disease pathogens. To prevent foodborne diseases, it is necessary to strengthen active monitoring, especially the sanitary management of seafood.

Hospitalisations due to bacterial gastroenteritis: A comparison of surveillance and hospital discharge data

Studies estimating the human health impact of the foodborne disease often include estimates of the number of gastroenteritis hospitalisations. The aims of this study were to examine the degree to which hospital discharge data underreport hospitalisations due to bacterial gastroenteritis and to estimate the frequency of stool sample submission among patients presenting with gastroenteritis. Using linked laboratory and hospital discharge data from a healthcare organisation and its affiliated hospital, we examined the International Classification of Disease (ICD-9-CM) diagnosis codes assigned to hospitalised adults with culture-confirmed Campylobacter, Salmonella, or Escherichia coli O157 infections and determined the frequency of stool sample submission. Among 138 hospitalised patients with culture-confirmed infections, 43% of Campylobacter patients, 56% of Salmonella patients and 35% of E. coli O157 patients had that pathogen-specific code listed on the discharge record. Among patients without their infection listed as a diagnosis, 65% were assigned a nonspecific gastroenteritis code. Submitting a specimen for culture ⩾3 days before discharge was significantly associated with having the pathogen-specific diagnosis listed. Of 6181 patients assigned a nonspecific gastroenteritis code, 69% had submitted a stool sample for bacterial culture. This study can be used to understand differences and adjust for the underreporting and underdiagnosed of Campylobacter, Salmonella and E. coli O157 in hospital discharge and surveillance data, respectively.

Characterization of Escherichia coli and Salmonella from Victoria, Australia, Dairy Farm Environments

Safe dairy food production starts at the farm level, with the presence of pathogens on farms potentially impacting the downstream food supply. Studies often commence with looking for pathogens in fecal material of farm animals, predominantly cows; however, pathogens may arise from other on-farm sources. In Australia, few studies have looked at the broader farm environment, particularly in relation to Escherichia coli and Salmonella. The present study characterized the genetic similarity of these pathogens from bovine, ovine, and caprine dairy farm environments and related this to the stx₁, stx₂, eae, or ehx virulence markers in E. coli and antibiotic resistance in Salmonella. E. coli isolates with indistinguishable genetic profiles and at least one of the virulence factors were found in multiple samples on the farms, although profiles were unique to each farm. E. coli O26 with stx₁ from one bovine farm had a different fingerprint type than all of the other E. coli O26 isolates, which lacked the Shiga toxin genes. They were from a separate bovine farm and were themselves closely related. No antibiotic resistance was detected among Salmonella isolates to the 17 antibiotics tested. Three Salmonella serotypes were identified: Orion, Infantis, and Zanzibar. The published PCR serotyping method used misidentified Salmonella Zanzibar as Salmonella Javiana, which was revealed after conventional antisera-based serotyping; this illustrates the need for caution when using PCR techniques for Salmonella serotype identification. Of the three serotypes, Salmonella Orion was most prevalent and was potentially resident on the farm. This article describes the previously unreported genetic diversity of potentially pathogenic E. coli and Salmonella serotypes from the farm environments of three dairy animal species in Victoria, Australia.

Surveillance for foodborne disease outbreaks in China, 2003 to 2008

Knowledge of implicated food vehicles and contributing factors derived from foodborne disease outbreak (FBDO) investigations allows consumers to be educated on decreasing high-risk behavior to reduce the risk of being affected by foodborne diseases. Food safety regulatory authorities also need summary of outbreak data, as these data indicate where the existing food supply system should be improved. To obtain information on epidemiology of FBDOs in China, FBDOs reported to the China National Foodborne Diseases Surveillance Network by 12 surveillance provinces that include 43% of the Chinese population was summarized. Between 2003 and 2008, 2795 FBDOs were reported, resulting in 62559 illnesses, 31261 hospitalizations, and 330 deaths. Outbreak size ranged from 2 to 464 cases, with a median of 14 cases. The outbreak rate had decreased from 1.37 per 1 million population in 2003 to 0.46 per 1 million population in 2008. Of the 2176 outbreaks with a single known etiology, bacteria (1051 outbreaks, 48%), man-made chemical hazards (550 outbreaks, 25%), and animal and plant toxins (536 outbreaks, 25%) were the main courses. Only one outbreak was caused by virus. Of the 1930 outbreaks with a single commodity, plant-based foods were the most common reported (930 outbreaks, 48%), followed by animal-based foods (590 outbreaks, 31%). Outbreaks most frequently occurred in private residences (32%), workplace cafeterias (21%), and restaurants (17%). The most common factor reported in the 2190 outbreaks with known contributing factors were improper cooking (510 outbreaks, 23%), contaminated ingredient (503 outbreaks, 23%), cross contamination (475 outbreaks, 22%) and improper storage (295 outbreaks, 13%). It is considered that FBDOs continue to be an important public health problem in China.

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This is up to now the most comprehensive summary on foodborne disease outbreaks in China.

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We described the epidemiology of foodborne disease outbreaks in China.

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This summary reviews data which was reported to the China National Foodborne Diseases Surveillance Network.

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Practical advice for improving foodborne disease outbreak surveillance in China is provided.

Characterization of Enterotoxigenic Bacillus cereus sensu lato and Staphylococcus aureus Isolates and Associated Enterotoxin Production Dynamics in Milk or Meat-Based Broth

Bacillus cereus sensu lato species, as well as Staphylococcus aureus, are important pathogenic bacteria which can cause foodborne illness through the production of enterotoxins. This study characterised enterotoxin genes of these species and examined growth and enterotoxin production dynamics of isolates when grown in milk or meat-based broth. All B. cereus s. l. isolates harboured nheA, hblA and entFM toxin genes, with lower prevalence of bceT and hlyII. When grown at 16 °C, toxin production by individual B. cereus s. l. isolates varied depending on the food matrix; toxin was detected at cell densities below 5 log₁₀(CFU/mL). At 16 °C no staphylococcal enterotoxin C (SEC) production was detected by S. aureus isolates, although low levels of SED production was noted. At 30 °C all S. aureus isolates produced detectable enterotoxin in the simulated meat matrix, whereas SEC production was significantly reduced in milk. Relative to B. cereus s. l. toxin production, S. aureus typically required reaching higher cell numbers to produce detectable levels of enterotoxin. Phylogenetic analysis of the sec and sel genes suggested population evolution which correlated with animal host adaptation, with subgroups of bovine isolates or caprine/ovine isolates noted, which were distinct from human isolates. Taken together, this study highlights the marked differences in the production of enterotoxins both associated with different growth matrices themselves, but also in the behaviour of individual strains when exposed to different food matrices.

Critical Review on the Public Health Impact of Norovirus Contamination in Shellfish and the Environment: A UK Perspective

We review the risk of norovirus (NoV) infection to the human population from consumption of contaminated shellfish. From a UK perspective, risk is apportioned for different vectors of NoV infection within the population. NoV spreads mainly by person-to-person contact or via unsanitary food handling. NoV also enters the coastal zone via wastewater discharges resulting in contamination of shellfish waters. Typically, NoV persists in the marine environment for several days, with its presence strongly linked to human population density, wastewater discharge rate, and efficacy of wastewater treatment. Shellfish bioaccumulate NoV and current post-harvest depuration is inefficient in its removal. While NoV can be inactivated by cooking (e.g. mussels), consumption of contaminated raw shellfish (e.g. oysters) represents a risk to human health. Consumption of contaminated food accounts for 3-11% of NoV cases in the UK (~74,000 cases/year), of which 16% are attributable to oyster consumption (11,800 cases/year). However, environmental and human factors influencing NoV infectivity remain poorly understood. Lack of standard methods for accurate quantification of infective and non-infective (damaged) NoV particles represent a major barrier, hampering identification of an appropriate lower NoV contamination limit for shellfish. Future management strategies may include shellfish quality assessment (at point of harvest or at point of supply) or harvesting controls. However, poor understanding of NoV inactivation in shellfish and the environment currently limits accurate apportionment and risk assessment for NoV and hence the identification of appropriate shellfish or environmental quality standards.

Diversity of Endophytic Bacteria in a Fern Species Dryopteris uniformis (Makino) Makino and Evaluation of Their Antibacterial Potential Against Five Foodborne Pathogenic Bacteria

The fern plant Dryopteris uniformis has traditionally been used in herbal medicine and possesses many biological activities. This study was conducted to explore the endophytic bacterial diversity associated with D. uniformis and evaluate their antibacterial potential against foodborne pathogenic bacteria (FPB). Among 51 isolated endophytic bacteria (EB), 26 EB were selected based on their morphological characteristics and identified by 16S rRNA gene analysis. The distribution of EB was diverse in the leaf and the stem/root tissues. When the EB were screened for antibacterial activity against five FPB, Listeria monocytogenes, Salmonella Typhimurium, Bacillus cereus, Staphylococcus aureus, and Escherichia coli O157:H7, four EB Bacillus sp. cryopeg, Paenibacillus sp. rif200865, Staphylococcus warneri, and Bacillus psychrodurans had a broad spectrum of antibacterial activity (9.58 ± 0.66 to 21.47 ± 0.27 mm inhibition zone). The butanol solvent extract of B. sp. cryopeg and P. sp. rif200865 displayed effective antibacterial activity against the five FPB, which was evident from the scanning electron microscopy with irregular or burst cell morphology in the EB-treated bacteria compared to smooth and regular cells in case of the control bacteria. The minimum inhibitory concentration and minimum bactericidal concentration values ranged between 250-500 μg/mL and 500-100 μg/mL, respectively. The above outcomes signify the huge prospective of the selected EB in the food industry. Overall, the above results suggested that D. uniformis contains several culturable EB that possess effective antibacterial compounds, and that EB can be utilized as a source of natural antibacterial agents for their practical application in food industry to control the spread of FPB as a natural antibacterial agent.

A Comparative Exposure Assessment of Campylobacter in Ontario, 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.

Nontyphoidal Salmonella Infection, Guangdong Province, China, 2012

We used active and passive surveillance to estimate nontyphoidal Salmonella (NTS) infection during 2012 in Guangdong Province, China. Under passive surveillance, for every reported NTS infection, an estimated 414.8 cases occurred annually. Under active surveillance, an estimated 35.8 cases occurred. Active surveillance provides remarkable advantages in incidence estimate.

A Review of Temperature, pH, and Other Factors that Influence the Survival of Salmonella in Mayonnaise and Other Raw Egg Products

Salmonellosis is one of the main causes of foodborne illnesses worldwide, with outbreaks predominately linked to contamination of eggs and raw egg products, such as mayonnaise. This review explores previous studies that have investigated Salmonella control mechanisms utilized in the production of raw egg mayonnaise and other food products. Apart from the use of pasteurized eggs, the main control mechanism identified is the pH of the raw egg products, which plays an important role in the consistency and stability while affecting the survival of Salmonella spp. However, currently there is no consensus regarding the critical pH limit for the control of Salmonella. The effectiveness of pH as a control mechanism is influenced by the type of acid used, with the effectiveness of lemon juice compared with vinegar highly debated. Additionally, Salmonella susceptibility to pH stresses may also be influenced by storage temperature (in some studies refrigeration temperatures protected Salmonella spp. from acidulants) and is further complicated by the development of Salmonella cross-tolerance-induced responses, pH homeostasis achieved by the cellular antiport and symport systems, and acid tolerance response (ATR). These mechanisms all provide Salmonella with an added advantage to ensure survival under various pH conditions. Other confounding factors include the fat content, and the addition of NaCl, garlic and plant essential oils (PEOs) from mint, cinnamon, cardamom and clove.

Modelling study to estimate the health burden of foodborne diseases: cases, general practice consultations and hospitalisations in the UK, 2009

OBJECTIVE

To generate estimates of the burden of UK-acquired foodborne disease accounting for uncertainty.

DESIGN

A modelling study combining data from national public health surveillance systems for laboratory-confirmed infectious intestinal disease (IID) and outbreaks of foodborne disease and 2 prospective, population-based studies of IID in the community. The underlying data sets covered the time period 1993-2008. We used Monte Carlo simulation and a Bayesian approach, using a systematic review to generate Bayesian priors. We calculated point estimates with 95% credible intervals (CrI).

SETTING

UK, 2009.

OUTCOME MEASURES

Pathogen-specific estimates of the number of cases, general practice (GP) consultations and hospitalisations for foodborne disease in the UK in 2009.

RESULTS

Bayesian approaches gave slightly more conservative estimates of overall health burden (∼511 000 cases vs 566 000 cases). Campylobacter is the most common foodborne pathogen, causing 280 400 (95% CrI 182 503-435 693) food-related cases and 38 860 (95% CrI 27 160-55 610) GP consultations annually. Despite this, there are only around 562 (95% CrI 189-1330) food-related hospital admissions due to Campylobacter, reflecting relatively low disease severity. Salmonella causes the largest number of hospitalisations, an estimated 2490 admissions (95% CrI 607-9631), closely followed by Escherichia coli O157 with 2233 admissions (95% CrI 170-32 159). Other common causes of foodborne disease include Clostridium perfringens, with an estimated 79 570 cases annually (95% CrI 30 700-211 298) and norovirus with 74 100 cases (95% CrI 61 150-89 660). Other viruses and protozoa ranked much lower as causes of foodborne disease.

CONCLUSIONS

The 3 models yielded similar estimates of the burden of foodborne illness in the UK and show that continued reductions in Campylobacter, Salmonella, E. coli O157, C. perfringens and norovirus are needed to mitigate the impact of foodborne disease.

Estimating healthcare costs of acute gastroenteritis and human campylobacteriosis in Switzerland

Rising numbers of campylobacteriosis case notifications in Switzerland resulted in an increased attention to acute gastroenteritis (AG) in general. Patients with a laboratory-confirmed Campylobacter infection perceive their disease as severe and around 15% of these patients are hospitalized. This study aimed at estimating healthcare costs due to AG and campylobacteriosis in Switzerland. We used official health statistics, data from different studies and expert opinion for estimating individual treatment costs for patients with different illness severity and for extrapolating overall costs due to AG and campylobacteriosis. We estimated that total Swiss healthcare costs resulting from these diseases amount to €29–45 million annually. Data suggest that patients with AG consulting a physician without a stool diagnostic test account for €9·0–24·2 million, patients with a negative stool test result for Campylobacter spp. for €12·3 million, patients testing positive for Campylobacter spp. for €1·8 million and hospitalized campylobacteriosis patients for €6·5 million/year. Healthcare costs of campylobacteriosis are high and most likely increasing in Switzerland considering that campylobacteriosis case notifications steadily increased in the past decade. Costs and potential cost savings for the healthcare system should be considered when designing sectorial and cross-sectorial interventions to reduce the burden of human campylobacteriosis in Switzerland.

Characterization of Staphylococcus aureus isolates from raw milk sources in Victoria, Australia

Background

Highly pathogenic strains of Staphylococcus aureus can cause disease in both humans and animals. In animal species, including ruminants, S. aureus may cause severe or sub-clinical mastitis. Dairy animals with mastitis frequently shed S. aureus into the milk supply which can lead to food poisoning in humans. The aim of this study was to use genotypic and immunological methods to characterize S. aureus isolates from milk-related samples collected from 7 dairy farms across Victoria.

Results

A total of 30 S. aureus isolates were collected from milk and milk filter samples from 3 bovine, 3 caprine and 1 ovine dairy farms across Victoria, Australia. Pulsed Field Gel Electrophoresis (PFGE) identified 11 distinct pulsotypes among isolates; all caprine and ovine isolates shared greater than 80 % similarity regardless of source. Conversely, bovine isolates showed higher diversity. Multi-Locus Sequence Typing (MLST) identified 5 different sequence types (STs) among bovine isolates, associated with human or ruminant lineages. All caprine and ovine isolates were ST133, or a single allele variant of ST133. Two new novel STs were identified among isolates in this study (ST3183 and ST3184). With the exception of these 2 new STs, eBURST analysis predicted all other STs to be founding members of their associated clonal complexes (CCs). Analysis of genetic markers revealed a diverse range of classical staphylococcal enterotoxins (SE) among isolates, with 11 different SEs identified among bovine isolates, compared with just 2 among caprine and ovine isolates. None of the isolates contained mecA, or were resistant to oxacillin. The only antibiotic resistance identified was that of a single isolate resistant to penicillin; this isolate also contained the penicillin resistance gene blaZ. Production of SE was observed at 16 °C and/or 37 °C in milk, however no SE production was detected at 12 °C.

Conclusion

Although this study characterized a limited number of isolates, bovine-associated isolates showed higher genetic diversity than their caprine or ovine counterparts. This was also reflected in a more diverse SE repertoire among bovine isolates. Very little antibiotic resistance was identified among isolates in this study. These results suggest maintaining the milk cold chain will minimise any risk from SE production and highlights the need to prevent temperature abuse.

Genotyping of Campylobacter coli strains isolated in Brazil suggests possible contamination amongst environmental, human, animal and food sources

Campylobacter coli and Campylobacter jejuni are two of the most common causative agents of food-borne gastroenteritis in numerous countries worldwide. In Brazil, campylobacteriosis is under diagnosed and under-reported, and few studies have molecularly characterized Campylobacter spp. in this country. The current study genotyped 63 C. coli strains isolated from humans (n512), animals (n521), food (n510) and the environment (n520) between 1995 and 2011 in Brazil. The strains were genotyped using pulsed-field gel electrophoresis (PFGE), sequencing the short variable region (SVR) of the flaA gene ( flaA-SVR) and high-resolution melting analysis (HRMA) of the clustered regularly interspaced short palindromic repeat (CRISPR) locus to better understand C. coli genotypic diversity and compare the suitability of these three methods for genotyping this species. Additionally, the discrimination index (DI) of each of these methods was assessed. Some C. coli strains isolated from clinical and non-clinical origins presented ≥80 % genotypic similarity by PFGE and flaA-SVR sequencing. HRMA of the CRISPR locus revealed only four different melting profiles. In total, 22 different flaA-SVR alleles were detected. Of these, seven alleles, comprising gt1647–gt1653, were classified as novel. The most frequent genotypes were gt30 and gt1647. This distribution reveals the diversity of selected Brazilian isolates in comparison with the alleles described in the PubMLST database. The DIs for PFGE, flaA–SVR sequencing and CRISPR-HRMA were 0.986, 0.916 and 0.550, respectively. PFGE and flaA-SVR sequencing were suitable for subtyping C. coli strains, in contrast to CRISPR-HRMA. The high genomic similarity amongst some C. coli strains confirms the hypothesis that environmental and food sources potentially lead to human and animal contamination in Brazil.

Use of Internet Search Queries to Enhance Surveillance of Foodborne Illness

“Food poisoning” queries were correlated with the number of foodborne illness–related hospital stays.

As a supplement to or extension of methods used to determine trends in foodborne illness over time, we propose the use of Internet search metrics. We compared Internet query data for foodborne illness syndrome–related search terms from the most popular 5 Korean search engines using Health Insurance Review and Assessment Service inpatient stay data for 26 International Classification of Diseases, Tenth Revision, codes for foodborne illness in South Korea during 2010–2012. We used time-series analysis with Seasonal Autoregressive Integrated Moving Average (SARIMA) models. Internet search queries for “food poisoning” correlated most strongly with foodborne illness data (r = 0.70, p<0.001); furthermore, “food poisoning” queries correlated most strongly with the total number of inpatient stays related to foodborne illness during the next month (β = 0.069, SE 0.017, p<0.001). This approach, using the SARIMA model, could be used to effectively measure trends over time to enhance surveillance of foodborne illness in South Korea.

Diarrheagenic pathogens in adults attending a hospital in Singapore

Background

Singapore’s diarrhoeal notification system is based on specific pathogens. Official data may thus be skewed towards notifiable diseases. Limited information is available on the profiles of aetiological agents responsible for acute gastroenteritis (AGE) cases, especially among the adult population. To understand the frequency and distribution of potential causative agents of diarrheal disease in Singapore, we screened adults’ stool samples collected from a large public hospital.

Methods

The stool samples were screened for 18 diarrheagenic pathogens using a combination of commercial multiplex polymerase chain reaction (PCR), in-house singleplex PCR and immunochromatographic assays. One hundred adult faecal samples that were collected from October 2013 to January 2014 for routine diagnostic purposes and submitted for culture at Tan Tock Seng Hospital, Singapore were used.

Results

Pathogens were detected in 32 % of the samples. The predominant organisms encountered were norovirus genogroup II (11 %), Aeromonas spp. (9 %) and Campylobacter spp. (5 %). One sample was positive for both verocytotoxigenic E. coli (VTEC) and E. coli O157:H7. Two other samples were positive for VTEC only, and one other sample was positive for E. coli O157:H7 only. Astrovirus, C. perfringens, Shigella spp. and toxigenic C. difficile were each detected in 2 % of the samples. Cryptosporidium parvum, Giardia lamblia, group A rotavirus, Salmonella spp. and Vibrio spp. were each detected in 1 % of the samples. No L. monocytogenes, Y. enterocolitica, enteric adenovirus, or norovirus genogroup I were detected.

Conclusion

Our preliminary findings suggest that pathogens causing non-notifiable diseases might have contributed considerably to the adult hospitalised AGE cases. However, as the samples were from an adult hospital, the data obtained may not be representative of the whole community. Thus, a larger study to collect clinical samples and risk exposure data from primary healthcare clinics and children hospital is planned for, to gain a more holistic perspective on the epidemiology of AGE in Singapore. A larger study may also offer valuable insights for improving the approach of microbiological surveillance of food, as well as strategizing inspection efforts along the food supply chain by public health authorities.

Utility of Bayesian networks in QMRA-based evaluation of risk reduction options for recycled water

BACKGROUND

Quantitative microbial risk assessment (QMRA), the current method of choice for evaluating human health risks associated with disease-causing microorganisms, is often constrained by issues such as availability of required data, and inability to incorporate the multitude of factors influencing risk. Bayesian networks (BNs), with their ability to handle data paucity, combine quantitative and qualitative information including expert opinions, and ability to offer a systems approach to characterisation of complexity, are increasingly recognised as a powerful, flexible tool that overcomes these limitations.

OBJECTIVES

We present a QMRA expressed as a Bayesian network (BN) in a wastewater reuse context, with the objective of demonstrating the utility of the BN method in health risk assessments, particularly for evaluating a range of exposure and risk mitigation scenarios. As a case study, we examine the risk of norovirus infection associated with wastewater-irrigated lettuce.

METHODS

A Bayesian network was developed following a QMRA approach, using published data, and reviewed by domain experts using a participatory process.

DISCUSSION

Employment of a BN facilitated rapid scenario evaluations, risk minimisation, and predictive comparisons. The BN supported exploration of conditions required for optimal outcomes, as well as investigation of the effect on the reporting nodes of changes in 'upstream' conditions. A significant finding was the indication that if maximum post-treatment risk mitigation measures were implemented, there was a high probability (0.84) of a low risk of infection regardless of fluctuations in other variables, including norovirus concentration in treated wastewater.

CONCLUSION

BNs are useful in situations where insufficient empirical data exist to satisfy QMRA requirements and they are exceptionally suited to the integration of risk assessment and risk management in the QMRA context. They allow a comprehensive visual appraisal of major influences in exposure pathways, and rapid interactive risk assessment in multifaceted water reuse scenarios.

World Health Organization Global Estimates and Regional Comparisons of the Burden of Foodborne Disease in 2010

Illness and death from diseases caused by contaminated food are a constant threat to public health and a significant impediment to socio-economic development worldwide. To measure the global and regional burden of foodborne disease (FBD), the World Health Organization (WHO) established the Foodborne Disease Burden Epidemiology Reference Group (FERG), which here reports their first estimates of the incidence, mortality, and disease burden due to 31 foodborne hazards. We find that the global burden of FBD is comparable to those of the major infectious diseases, HIV/AIDS, malaria and tuberculosis. The most frequent causes of foodborne illness were diarrheal disease agents, particularly norovirus and Campylobacter spp. Diarrheal disease agents, especially non-typhoidal Salmonella enterica, were also responsible for the majority of deaths due to FBD. Other major causes of FBD deaths were Salmonella Typhi, Taenia solium and hepatitis A virus. The global burden of FBD caused by the 31 hazards in 2010 was 33 million Disability Adjusted Life Years (DALYs); children under five years old bore 40% of this burden. The 14 subregions, defined on the basis of child and adult mortality, had considerably different burdens of FBD, with the greatest falling on the subregions in Africa, followed by the subregions in South-East Asia and the Eastern Mediterranean D subregion. Some hazards, such as non-typhoidal S. enterica, were important causes of FBD in all regions of the world, whereas others, such as certain parasitic helminths, were highly localised. Thus, the burden of FBD is borne particularly by children under five years old-although they represent only 9% of the global population-and people living in low-income regions of the world. These estimates are conservative, i.e., underestimates rather than overestimates; further studies are needed to address the data gaps and limitations of the study. Nevertheless, all stakeholders can contribute to improvements in food safety throughout the food chain by incorporating these estimates into policy development at national and international levels.