A Multifactorial Risk Prioritization Framework for Foodborne Pathogens

We develop a prioritization framework for foodborne risks that considers public health impact as well as three other factors (market impact, consumer risk acceptance and perception, and social sensitivity). Canadian case studies are presented for six pathogen‐food combinations: Campylobacter spp. in chicken; Salmonella spp. in chicken and spinach; Escherichia coli O157 in spinach and beef; and Listeria monocytogenes in ready‐to‐eat meats. Public health impact is measured by disability‐adjusted life years and the cost of illness. Market impact is quantified by the economic importance of the domestic market. Likert‐type scales are used to capture consumer perception and acceptance of risk and social sensitivity to impacts on vulnerable consumer groups and industries. Risk ranking is facilitated through the development of a knowledge database presented in the format of info cards and the use of multicriteria decision analysis (MCDA) to aggregate the four factors. Three scenarios representing different stakeholders illustrate the use of MCDA to arrive at rankings of pathogen‐food combinations that reflect different criteria weights. The framework provides a flexible instrument to support policymakers in complex risk prioritization decision making when different stakeholder groups are involved and when multiple pathogen‐food combinations are compared.     

Disadvantage and Discrimination Compounded: the experience of Pakistani and Bangladeshi parents of disabled children in the UK

This paper discusses a qualitative and quantitative study of the circumstances of 20 Pakistani and Bangladeshi families with one or more severely disabled children living in Birmingham, England. Parents and other adult carers were interviewed using a combination of structured questionnaires and a semi-structured interview schedule focusing on the families' material circumstances, their use of formal services, informal care arrangements, and aspects of the parents' social and psychological well-being. The study suggests that previous national surveys of disabled families may have under-estimated the extent of material disadvantage, while it confirms that health and social care professionals should not assume that Pakistani and Bangladeshi parents have recourse to high levels of extended family support. The combination of disadvantaged circumstances and difficulties in securing access to appropriate services, which are found for the majority of families with a disabled child, was particularly acute for these ethnic minority families, suggesting the additional dimension of institutional racism.     

A Risk Assessment Model to Evaluate the Role of Fecal Contamination in Recreational Water on the Incidence of Cryptosporidiosis at the Community Level in Ontario

A quantitative microbial risk assessment model was developed to simulate the role of recreational water contact in the transmission of cryptosporidiosis in a model Ontario community. Stochastic simulations were based on plausible modes of contamination of a pool (literature derived), river (site-specific), and recreational lakes (literature derived). The highest estimated risks of infection were derived from the (highly contaminated) recreational lake scenario, considered the upper end for risk of infection for both children (10 infections per 1,000 swims [5‰: two infections per 1,000 swims; 95‰: three infections per 100 swims]) and adults (four infections per 1,000 swims [5‰: four infections per 1,000 swims; 95‰: one infection per 100 swims]). Simulating the likely  Cryptosporidium  oocyst concentration in a lane pool that a child would be exposed to following a diarrheal fecal release event resulted in the third highest mean risk of infection (four infections per 10,000 swims [5‰: three infections per 100,000; 95‰: 10 infections per 10,000 swims]). The findings from this study illustrate the need for systematic and standardized research to quantify  Cryptosporidium  oocyst levels in Canadian public pools and recreational beaches. There is also a need to capture the swimming practices of the Canadian public, including most common forms and frequency measures. The study findings suggest that swimming in natural swim environments and in pools following a recent fecal contamination event pose significant public health risks. When considering these risks relative to other modes of cryptosporidiosis transmission, they are significant.     

Disability, Ethnicity and Childhood: a critical review of research

Whilst there is an increasing body of literature on the perspectives of carers of disabled children, there is little research giving the disabled child's perspective from either majority or minority populations. Indeed, the voices of black and Asian children in disability research have been almost silent. This literature review collates and analyses existing knowledge about the perceptions held by disabled and non-disabled children, and young people from black and Asian families concerning issues of disability and impairment. The Disability Movement has long proclaimed its belief in the full participation and self-representation of all disabled people. However, despite this laudable objective, the Disability Movement in Britain has mirrored society in general and for the most part been led by white, middle-class, heterosexual, articulate males. This review discusses the simultaneous oppression faced by black and Asian disabled children, and concludes that their experience is unique and different from that of white disabled children. Accordingly, it emphasises the need for further research about the subjective experience of black and Asian disabled children in order to meet their particular needs.     

A characterization of geometric distribution based on weak records

Let \({\{X_n, n\geq 1\}}\) be a sequence of independent and identically distributed non-degenerated random variables with common cumulative distribution function F. Suppose X ₁ is concentrated on 0, 1, . . . , N ≤ ∞ and P(X ₁ = 1) > 0. Let \({X_{U_w(n)}}\) be the n-th upper weak record value. In this paper we show that for any fixed m ≥ 2, X ₁ has Geometric distribution if and only if \({X_{U_{w}(m)}\mathop=\limits^d X_1+\cdots+X_m ,}\) where \({\underline{\underline{d}}}\) denotes equality in distribution. Our result is a generalization of the case m = 2 obtained by Ahsanullah (J Stat Theory Appl 8(1):5–16, 2009).     

Harnessing the Theoretical Foundations of the Exponential and Beta‐Poisson Dose‐Response Models to Quantify Parameter Uncertainty Using Markov Chain Monte Carlo

Dose‐response models are the essential link between exposure assessment and computed risk values in quantitative microbial risk assessment, yet the uncertainty that is inherent to computed risks because the dose‐response model parameters are estimated using limited epidemiological data is rarely quantified. Second‐order risk characterization approaches incorporating uncertainty in dose‐response model parameters can provide more complete information to decisionmakers by separating variability and uncertainty to quantify the uncertainty in computed risks. Therefore, the objective of this work is to develop procedures to sample from posterior distributions describing uncertainty in the parameters of exponential and beta‐Poisson dose‐response models using Bayes's theorem and Markov Chain Monte Carlo (in OpenBUGS). The theoretical origins of the beta‐Poisson dose‐response model are used to identify a decomposed version of the model that enables Bayesian analysis without the need to evaluate Kummer confluent hypergeometric functions. Herein, it is also established that the beta distribution in the beta‐Poisson dose‐response model cannot address variation among individual pathogens, criteria to validate use of the conventional approximation to the beta‐Poisson model are proposed, and simple algorithms to evaluate actual beta‐Poisson probabilities of infection are investigated. The developed MCMC procedures are applied to analysis of a case study data set, and it is demonstrated that an important region of the posterior distribution of the beta‐Poisson dose‐response model parameters is attributable to the absence of low‐dose data. This region includes beta‐Poisson models for which the conventional approximation is especially invalid and in which many beta distributions have an extreme shape with questionable plausibility.