Restriction fragment length polymorphism of polymerase chain reaction products applied to the differentiation of poultry campylobacters for epidemiological investigations

A technique for subtyping Camplobacter jejuni isolates has been developed by using the restriction fragment length polymorphism (Rnp) of polymerase chain reaction (PCR) products of the fluA and flaB genes. The technique was validated by using strains representing 28 serotypes of C jejuni and it may also be applied to C coli. From these strains 12 distinct RFLP profiles were observed but there was no direct relationship between the RFLP profile and the serotype. One hundred and thirty-five campylobacter isolates from 15 geographically distinct broiler flocks were investigated. All the isolates could be subtyped by using the RFLP method. Isolates from most of the flocks had a single RFLP profile despite data indicating that several serotypes were involved. Although it is possible that further restriction analysis may have demonstrated profile variations in these strains, it is more likely that antigenic variation can occur within genotypically related campylobacters. As a result, serotyping may give conflicting information for veterinary epidemiological purposes. This RFLP typing scheme appears to provide a suitable tool for the investigation of the sources and routes of transmission of campylobacters in chickens.

Low-grade inflammation, diet composition and health: current research evidence and its translation

The importance of chronic low-grade inflammation in the pathology of numerous age-related chronic conditions is now clear. An unresolved inflammatory response is likely to be involved from the early stages of disease development. The present position paper is the most recent in a series produced by the International Life Sciences Institute's European Branch (ILSI Europe). It is co-authored by the speakers from a 2013 workshop led by the Obesity and Diabetes Task Force entitled ‘Low-grade inflammation, a high-grade challenge: biomarkers and modulation by dietary strategies’. The latest research in the areas of acute and chronic inflammation and cardiometabolic, gut and cognitive health is presented along with the cellular and molecular mechanisms underlying inflammation–health/disease associations. The evidence relating diet composition and early-life nutrition to inflammatory status is reviewed. Human epidemiological and intervention data are thus far heavily reliant on the measurement of inflammatory markers in the circulation, and in particular cytokines in the fasting state, which are recognised as an insensitive and highly variable index of tissue inflammation. Potential novel kinetic and integrated approaches to capture inflammatory status in humans are discussed. Such approaches are likely to provide a more discriminating means of quantifying inflammation–health/disease associations, and the ability of diet to positively modulate inflammation and provide the much needed evidence to develop research portfolios that will inform new product development and associated health claims.

Dusting off the epidemiological triad: could it work with obesity

The search for effective ways of dealing with obesity has centred on biological research and clinical management. However, obesity needs to be conceptualized more broadly if the modern pandemic is to be arrested. The epidemiological triad (hosts, agent/vectors and environments) has served us well in dealing with epidemics in the past, and may be worth re-evaluating to this end. Education, behaviour change and clinical practices deal predominantly with the host, although multidisciplinary practices such as shared-care might also be expected to impact on other corners of the triad. Technology deals best with the agent of obesity (energy imbalance) and it's vectors (excessive energy intake and/or inadequate energy expenditure), and policy and social change are needed to cope with the environment. The value of a broad model like this, rather than specific isolated approaches, is that the key players such as legislators, health professionals, governments and industry can see their roles in attenuating and eventually reversing the epidemic. It also highlights the need to intervene at all levels in obesity control and reduces the relevance of arguments about nature vs. nurture.


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Teaching research and epidemiology to undergraduate students in the health sciences

Objective: To identify and address particular challenges in the teaching of epidemiological concepts to undergraduate students in non-clinical health disciplines. Methods and Results: Relevant pedagogical literature was reviewed to identify a range of evidence-based teaching approaches. The authors also drew on their experience in curriculum development and teaching in this field to provide guidelines for teaching epidemiology in a way that is engaging to students and likely to promote deep, rather than surface, learning. Discussion of a range of practical strategies is included along with applied examples of teaching epidemiological content. Conclusions and Implications: Increasingly, there is a greater emphasis on improved learning outcomes in higher education. Graduates from non-clinical health courses are required to have a core understanding of epidemiology and teachers of epidemiology need to be able to access resources that are relevant and useful for these students. A theoretically grounded framework for effective teaching of epidemiological principles to non-clinical undergraduates is provided, together with a range of useful teaching resources (both paper and web-based). Implementation of the strategies discussed will help ensure graduates are able to appropriately apply epidemiological skills in their professional practice.

Communication outside the humanities in media 'effect' research

This paper draws on the case study of a recent review of research literature on the influences (harms and benefits) on children and families of electronic media content and usage, undertaken on behalf of a Federal regulatory body (Australian Communications and Media Authority) by a multidisciplinary research team. Recent critiques of psychological studies of children and media have challenged the positivist social sciences to look outside of their own disciplinary warrants and to fully answer cultural studies critiques of ‘media effects’ research. Making connections outside the humanities in this case study involved making the rationales of communications and cultural studies methodologies available to those policy makers who normally may not consider such findings to be evidence-based or policy relevant. But it also involved providing a historical and institutional contextualization of positivist social and medical science findings, a contextualization not enabled by the underlying warrants and discourses of these disciplines. This paper focuses on those sections of the case study project concerned with psychological research on the effects of violent media and epidemiological and public health research on childhood obesity.

Assessing epidemiological learning amongst undergraduate students

Increasingly, students from a range of undergraduate health courses are required to study epidemiology. This is, in part, due to the use of evidence-based frameworks and workforce competency programs. Resources to guide the selection of content and development of teaching strategies are available. However, there is paucity of published research on how to best assess epidemiological knowledge and skills. Using recent experience and a review of the current evidence on best practice in assessment, this paper outlines how the key principles in assessment can be used in epidemiology to encourage students to learn and apply epidemiological skills in their professional practice and promote inter-professional learning and co-operation.

Overview of risk prediction models in cardiovascular disease research

Many risk prediction models have been developed for cardiovascular diseases in different countries during the past three decades. However, there has not been consistent agreement regarding how to appropriately assess a risk prediction model, especially when new markers are added to an established risk prediction model. Researchers often use the area under the receiver operating characteristic curve (ROC) to assess the discriminatory ability of a risk prediction model. However, recent studies suggest that this method has serious limitations and cannot be the sole approach to evaluate the usefulness of a new marker in clinical and epidemiological studies. To overcome the shortcomings of this traditional method, new assessment methods have been proposed. The aim of this article is to overview various risk prediction models for cardiovascular diseases, to describe the receiver operating characteristic curve method and discuss some new assessment methods proposed recently. Some of the methods were illustrated with figures from a cardiovascular disease study in Australia.

Comparing probability and non-probability sampling methods in ecstasy research : implications for the internet as a research tool

The usage of Ecstasy and related drug (ERD) has increasingly been the focus of epidemiological and other public health-related research. One of the more promising methods is the use of the Internet as a recruitment and survey tool.However, there remain methodological concerns and questions about representativeness. Three samples of ERD users in Melbourne, Australia surveyed in 2004 are compared in terms of a number of key demographic and drug use variables. The Internet, face-to-face, and probability
sampling methods appear to access similar but not identical groups of ERD users. Implications and limitations of the study are noted and future research is recommended.

Getting research into policy : lots of ideas but how do we make it happen? Insights from the policy experience

Evidence and health policy discussions to date have largely focused on the relationship between those generating research evidence and policy decision-makers and how improving this relationship will increase research use in policy development. All too often policy makers are perceived as the problem, not understanding or seeing the importance of research evidence. Policy makers do have a responsibility to source and use available evidence, as do researchers to the sharp and meaningful production and syntheses of policy relevant research evidence. This takes more than improved communication mechanisms between individual researcher and policy makers. Evidence-informed policy making is a science in its own right requiring the development and application of methods that conceptualise, synthesise and exchange research evidence. Policy organisations need to develop as receptor sites for research and its application to day-to-day decision-making, this is a significant program of work if it is to be done well and affect the evidence culture of organisations.

Using the Rose Angina Questionnaire cross-culturally : the importance of consulting lay people when translating epidemiological questionnaires

Objectives. The Rose Angina Questionnaire (RAQ) is an important measure of coronary heart disease prevalence. It has been shown to perform inconsistently across some ethnic groups in Britain. This study investigates whether the best available versions of the RAQ in Punjabi and Cantonese were linguistically equivalent to the English version.

Design. Interviews were carried out with lay people from the Pakistani, Chinese and European-origin communities in Scotland to assess the versions of the RAQ used in the Newcastle Heart Project (the best available versions). For each questionnaire item, participants were asked to elaborate on their understanding of the question and the meaning of keywords or phrases.

Results. Problems were discovered with the Punjabi and Cantonese translations of the RAQ. For example, the translation for ‘chest’ was interpreted by some Pakistani and Chinese women to mean ‘breasts’. ‘Walking uphill’ was translated in Chinese as ‘walking the hill’, without stipulation of the direction, so that some Cantonese speakers interpreted the question as pertaining to walking downhill. Many Chinese interpreted RAQ items to be referring to breathlessness rather than chest pain due to ambiguous wording.

Conclusion. Existing versions of the RAQ are unlikely to be yielding data that are cross-culturally valid or comparable. For robust health survey research in languages other than that in which the questionnaire was developed, lay assessment of questionnaires prior to and after translation is a necessity rather than a luxury.

Cigarette smoking, nicotine dependence and anxiety disorders : a systematic review of population-based, epidemiological studies

Background Multiple studies have demonstrated that rates of smoking and nicotine dependence are increased in individuals with anxiety disorders. However, significant variability exists in the epidemiological literature exploring this relationship, including study design (cross-sectional versus prospective), the population assessed (random sample versus clinical population) and diagnostic instrument utilized.

Methods We undertook a systematic review of population-based observational studies that utilized recognized structured clinical diagnostic criteria (Diagnostic and Statistical Manual of Mental Disorders (DSM) or International Classification of Diseases (ICD)) for anxiety disorder diagnosis to investigate the relationship between cigarette smoking, nicotine dependence and anxiety disorders.

Results In total, 47 studies met the predefined inclusion criteria, with 12 studies providing prospective information and 5 studies providing quasiprospective information. The available evidence suggests that some baseline anxiety disorders are a risk factor for initiation of smoking and nicotine dependence, although the evidence is heterogeneous and many studies did not control for the effect of comorbid substance use disorders. The identified evidence however appeared to more consistently support cigarette smoking and nicotine dependence as being a risk factor for development of some anxiety disorders (for example, panic disorder, generalized anxiety disorder), although these findings were not replicated in all studies. A number of inconsistencies in the literature were identified.

Conclusions Although many studies have demonstrated increased rates of smoking and nicotine dependence in individuals with anxiety disorders, there is a limited and heterogeneous literature that has prospectively examined this relationship in population studies using validated diagnostic criteria. The most consistent evidence supports smoking and nicotine dependence as increasing the risk of panic disorder and generalized anxiety disorder. The literature assessing anxiety disorders increasing smoking and nicotine dependence is inconsistent. Potential issues with the current literature are discussed and directions for future research are suggested.

An epidemiological analysis of the 'autism as mercury poisoning' hypothesis

Where direct experimental research into a causal hypothesis of a disease is impossible due to ethical and practical considerations, epidemiological inference is the accepted route to establishing cause. Therefore, to examine the autism as mercury poisoning hypothesis, this paper reviews the existing scientific literature within the context of established epidemiological criteria and finds that the evidence for a causal relationship is compelling. Exposure to mercury (via vaccines and maternal dental amalgam) in utero and during infant years is confirmed; mercury poisoning is known to cause symptoms consistent with autism; animal modeling supports the link and, critically, mercury levels are higher in both the urine and blood of autistic children than in non-autistic peers. Analogous to epidemiological evidence of the smoking–lung cancer relationship, a mercury–autism relationship is confirmed. The precautionary principle demands that health professionals not take an action if there is suspicion that the action may cause severe or lifelong health effects: it does not require certainty. Therefore, given the severity, devastating lifelong impact and extremely high prevalence of autism, it would be negligent to continue to expose pregnant and nursing mothers and infant children to any amount of avoidable mercury.