Laura Ford

Foodborne Illness, Australia, Circa 2000 and Circa 2010

Overall incidence of foodborne gastroenteritis declined but remains high, and the incidence of salmonellosis and campylobacteriosis increased.

Proportion of Illness Acquired by Foodborne Transmission for Nine Enteric Pathogens in Australia: An Expert Elicitation

BACKGROUND Estimates of the burden of illness acquired from food inform public health policy and prioritize interventions. A key component of such estimates is the proportion of illnesses that are acquired by foodborne transmission. In view of the shortage of requisite data, these proportions are commonly obtained through a process known as expert elicitation. We report findings from an elicitation process used to assess the importance of the foodborne transmission route for nine pathogens in Australia, circa 2010. MATERIALS AND METHODS Eleven experts were asked to estimate the proportion of illness acquired by five transmission routes: food, environmental, water, person, and zoonotic, together with a 90% certainty interval for foodborne transmission. Foodborne estimates and intervals from each expert were combined using both modified triangular and Program Evaluation and Review Technique (PERT) distributions, in @Risk version 6, to generate final distributions from which median estimates and 95% Credible Intervals (CrI) were calculated. RESULTS Shiga toxin-producing Escherichia coli (STEC) was the only pathogen believed to have an important zoonotic transmission route, while norovirus, hepatitis A virus, non-STEC pathogenic E. coli, and Shigella spp. were all thought to be primarily spread from person to person. Foodborne transmission was the main route for Clostridium perfringens (98%, CrI: 84-100), Listeria monocytogenes (98%, CrI: 86-100), nontyphoidal Salmonella spp. (72%, CrI: 50-87), and Campylobacter spp. (77%, CrI: 60-90). Foodborne estimates using the modified triangular distribution had wider CrI than these calculated using the PERT distribution. CONCLUSIONS Foodborne proportions for most pathogens in this study were the same or lower than those estimated circa 2000 in Australia, with the greatest decline for non-STEC pathogenic E. coli. Inclusion of certainty intervals from experts helps to quantify the precision of foodborne proportions. A decline in estimates of the foodborne proportion for common pathogens will influence final estimates of the burden of illness acquired from food.

Bayesian Source Attribution of Salmonellosis in South Australia.

Salmonellosis is a significant cause of foodborne gastroenteritis in Australia, and rates of illness have increased over recent years. We adopt a Bayesian source attribution model to estimate the contribution of different animal reservoirs to illness due to Salmonella spp. in South Australia between 2000 and 2010, together with 95% credible intervals (CrI). We excluded known travel associated cases and those of rare subtypes (fewer than 20 human cases or fewer than 10 isolates from included sources over the 11-year period), and the remaining 76% of cases were classified as sporadic or outbreak associated. Source-related parameters were included to allow for different handling and consumption practices. We attributed 35% (95% CrI: 20-49) of sporadic cases to chicken meat and 37% (95% CrI: 23-53) of sporadic cases to eggs. Of outbreak-related cases, 33% (95% CrI: 20-62) were attributed to chicken meat and 59% (95% CrI: 29-75) to eggs. A comparison of alternative model assumptions indicated that biases due to possible clustering of samples from sources had relatively minor effects on these estimates. Analysis of source-related parameters showed higher risk of illness from contaminated eggs than from contaminated chicken meat, suggesting that consumption and handling practices potentially play a bigger role in illness due to eggs, considering low Salmonella prevalence on eggs. Our results strengthen the evidence that eggs and chicken meat are important vehicles for salmonellosis in South Australia.

Sequelae of foodborne illness caused by 5 pathogens, Australia, circa 2010.

Foodborne gastroenteritis results in a substantial amount of severe and disabling sequelae.

Addressing inequities in healthy eating

What, when, where and how much people eat is influenced by a complex mix of factors at societal, community and individual levels. These influences operate both directly through the food system and indirectly through political, economic, social and cultural pathways that cause social stratification and influence the quality of conditions in which people live their lives. These factors are the social determinants of inequities in healthy eating. This paper provides an overview of the current evidence base for addressing these determinants and for the promotion of equity in healthy eating.

Potential environmental and population health impacts of local urban food systems under climate change: a life cycle analysis case study of lettuce and chicken

BackgroundClimate change is expected to have an impact on food production, processing and transport systems. While food systems have become globalized in recent decades, interest has re-emerged for local production and consumption to contribute to sustainable and secure food systems in an era of increasing urbanization and climate change. To explore environmental health issues related to the production of local food in an urban setting, a life cycle analysis screening study of two food commodities, chicken meat and lettuce, produced at industrial and civic scales was conducted in Sydney, Australia, as well as interviews with consumers and producers to explore their potential motivation to change.MethodsDetermination of environmental impacts was performed using life cycle assessment (LCA) of two civic and one industrial scale producer for each commodity using SimaPro version 7.3.3. Impacts of global warming potential (GWP), land use and water use from the production of these commodities are reported. With a view to producing holistic insights to sustainable practices in Sydney, interviews with producers and consumers were undertaken to assess sociocultural outcomes including views on environmental food sustainability and other motivators of behavioral change.ResultsLocal industrial production of chicken meat was found to have a lower carbon footprint than small scale civic production. Small scale civic production of lettuce had a similar carbon footprint to local industrial production. Other environmental health benefits and risks varied across the production scales. Environmental sustainability was not generally a key concern of producers or consumers.ConclusionsAction can be taken to retain and promote food production in urban settings as a future means of assisting food security. The scale of production can be an important variable in assessing the environmental health impacts of food production in an urban setting. Currently neither producers nor consumers appear motivated to change practices to promote environmental sustainability.

Increasing Incidence of Salmonella in Australia, 2000-2013

Salmonella is a key cause of foodborne gastroenteritis in Australia and case numbers are increasing. We used negative binomial regression to analyze national surveillance data for 2000–2013, for Salmonella Typhimurium and non-Typhimurium Salmonella serovars. We estimated incidence rate ratios adjusted for sex and age to show trends over time. Almost all states and territories had significantly increasing trends of reported infection for S. Typhimurium, with states and territories reporting annual increases as high as 12% (95% confidence interval 10–14%) for S. Typhimurium in the Australian Capital Territory and 6% (95% CI 5–7%) for non-Typhimurium Salmonella in Victoria. S. Typhimurium notification rates were higher than non-Typhimurium Salmonella rates in most age groups in the south eastern states of Australia, while non-Typhimurium rates were higher in most age groups elsewhere. The S. Typhimurium notification rate peaked at 12–23 months of age and the non-Typhimurium Salmonella notification rate peaked at 0–11 months of age. The age-specific pattern of S. Typhimurium cases suggests a foodborne origin, while the age and geographic pattern for non-Typhimurium may indicate that other transmission routes play a key role for these serovars.

Drivers of uncertainty in estimates of foodborne gastroenteritis incidence

BACKGROUND Estimates of the incidence of foodborne illness are increasingly used at national and international levels to quantify the burden of disease and advocate for improvements in food safety. The calculation of such estimates involves multiple datasets and several disease multipliers, applied to dozens of pathogens. Unsurprisingly, this process often produces wide interval estimates. MATERIALS AND METHODS Using a model of foodborne gastroenteritis in Australia, we calculate the contribution of both data and multipliers to the width of the interval. We then compare pathogen-specific estimates of the proportion of gastroenteritis that is foodborne from national-level studies conducted in Canada, Greece, France, the Netherlands, New Zealand, the United Kingdom, and the United States. RESULTS Overall, we estimate that 74% (range 63-92%) of the interval width for foodborne gastroenteritis in Australia is a result of uncertainty in the proportion of gastroenteritis that is due to contaminated food. Across national studies, we find considerable variability in point estimates and the width of interval estimates for the foodborne proportion for relatively common pathogens such as Salmonella spp., Campylobacter spp., and norovirus. CONCLUSIONS While some uncertainty in estimates of gastroenteritis incidence is inevitable, an understanding of the drivers of this uncertainty can help to focus further research. In particular, this work highlights the value of studies quantifying the routes of transmission for common pathogens.

Promoting equity in the mental wellbeing of children and young people: A scoping review

There is increasing emphasis on wellbeing as a target for mental health promotion, especially during the formative period of childhood. Despite growing research on the importance of mental wellbeing, there is little information on how to effectively promote it or how to promote it equitably. This article presents a scoping review of interventions which seek to promote mental wellbeing and reduce inequities in children and young people living in high income countries. We used Fair Foundations: The VicHealth framework for health equity (VicHealth (2013) Melbourne, Australia: The Victorian Health Promotion Foundation) to identify points of entry at three layers of influence: (i) socioeconomic, cultural and political contexts, (ii) daily living conditions, and (iii) individual and family health-related factors. We identified more than 1000 interventions which aimed to prevent or treat childhood mental illness, but there were far fewer that aimed to promote childrens or young peoples mental wellbeing. The interventions we studied were either universal or specifically targeted children from disadvantaged families: none explicitly used an equity framework to guide their design or evaluation or addressed social gradients in wellbeing. Most interventions remained focused on proximate factors, although we also identified a handful of interventions that sought to address childrens access to services and their educational and neighbourhood environments. However, we found encouraging evidence that interventions in family and educational settings were successful in building childrens strengths and supporting positive parenting, universally and within disadvantaged groups. Such positive programme evaluations signal the potential for using a proportionate universalism approach that emphasizes equity in the promotion of mental wellbeing.

Approaches to the Surveillance of Foodborne Disease: A Review of the Evidence

Foodborne disease surveillance aims to reduce the burden of illness due to contaminated food. There are several different types of surveillance systems, including event-based surveillance, indicator-based surveillance, and integrated food chain surveillance. These approaches are not mutually exclusive, have overlapping data sources, require distinct capacities and resources, and can be considered a hierarchy, with each level being more complex and resulting in a greater ability to detect and control foodborne disease. Event-based surveillance is generally the least resource-intensive system and makes use of informal data sources. Indicator-based surveillance is seen as traditional notifiable disease surveillance and consists of routinely collected data. Integrated food chain surveillance is viewed as the optimal practice for conducting continuous risk analysis for foodborne diseases, but also requires significant ongoing resources and greater multisectoral collaboration compared to the other systems. Each country must determine the most appropriate structure for their surveillance system for foodborne diseases based on their available resources. This review explores the evidence on the principles, minimum capabilities, and minimum requirements of each type of surveillance and discusses examples from a range of countries. This review forms the evidence base for the Strengthening the Surveillance and Response for Foodborne Diseases: A Practical Manual.