Participatory epidemiology: Reviewing experiences with contexts and actions.

This paper reviews experiences with participatory epidemiology (PE) and focuses in pastoralist areas of Africa where much of the early development and institutionalization of PE occurred. The paper discusses the importance of context when designing PE activities and framing study questions, and uses the example of changing livelihoods in pastoralist areas, and marked wealth and gender differences within communities. By reference to a recently proposed definition of PE that includes community empowerment, the paper describes the marked socio-economic and gender differentiation in pastoralist communities. In these contexts, questions of "disease control for who?" and "empowerment for who?" arise, as does the need to move beyond the concept of communities as homogenous social and economic units. By reference to the persistent complex emergencies and other humanitarian crises, the paper discusses community participation and how functional participation in programmes and PE can contribute to successful livestock disease control. In contrast, empowering forms of participation are difficult to achieve in humanitarian contexts and might not be needed to achieve effective livestock disease control. In non-humanitarian contexts, and secure countries with stable governments, national control programmes for important transboundary or zoonotic diseases usually require control strategies that can be applied consistently across areas, and with disease policy, funding, coordination and implementation controlled centrally. In contrast, empowerment in PE implies local, community-level decision-making and control of resources. The paper also discusses importance of designing PE studies that focus on action, and participatory evaluation of new or adapted disease control methods with communities.

"Can we agree on that"? Plurality, power and language in participatory research.

Participatory epidemiology (PE) is a method that gathers data from groups through focus group interviews and participatory visual and scoring exercises. The method is often used in poor communities in low-income countries where it is hard to obtain conventional epidemiological data. This paper draws on research on the public sphere and democratic deliberation, along with research on language and interpretation, to suggest how PE research could be better equipped to account for diversity in local knowledge, include minority views and acknowledge power dynamics. These aspects are discussed under the three themes of 'plurality', 'power' and 'language'. A review of highly-cited PE literature suggests that PE research engages with plurality and power to a very limited extent, and only marginally more so with language and translation. Examples are taken from the authors' own PE research on African swine fever in -Uganda, classical swine fever in Germany, peste des petits ruminants (PPR) in Eastern Europe, and Ugandan pastoralists' understanding of cattle disease to provide more detail as to why conventional PE studies might fail to record issues of plurality, power and language, and also to suggest how this can be addressed. With reference to the literature on the public sphere and democratic deliberation, and on language and interpretation, this paper concludes with some suggestions as to how to take plurality, power and language into greater consideration in PE studies in future, thus improving the validity and reliability of PE data.

Building the foundation for veterinary register-based epidemiology: A systematic approach to data quality assessment and validation.

Epidemiological studies often use data from registers. Data quality is of vital importance for the quality of the research. The aim of this study was to suggest a structured workflow to assess the quality of veterinary national registers. As an example of how to use the workflow, the quality of the following three registers was assessed: the Central Husbandry Register (CHR), the database for movement of pigs (DMP) and the national Danish register of drugs for veterinary use (VetStat). A systematic quantitative assessment was performed, with calculation the proportion of farms and observations with "poor quality" of data. "Poor" quality was defined for each measure (variable) either as a mismatch between and/or within registers, registrations of numbers outside the expected range, or unbalanced in- and outgoing movements. Interviews were conducted to make a complementary qualitative assessment. The proportion of farms and observations within each quality measure varied. This study highlights the importance of systematic quality assessment of register data and suggests a systematic approach for such assessments and validations without the use of primary data.

The application of epidemiology in national veterinary services: Challenges and threats in Brazil.

The application of epidemiology in national veterinary services must take place at the interface between science and politics. Animal health policy development and implementation require attention to macro-epidemiology, the study of economic, social and policy inputs that affect the distribution and impact of animal or human disease at the national level. The world has changed fast over the last three decades including the delivery of veterinary services, their remit and the challenges addressed by public and animal health policies. Rethinking the role of public services and how to make public programs more efficient has been at the heart of the political discussion. The WTO through its SPS Agreement has changed the way in which national veterinary services operate and how trade decisions are made. Most low and middle income countries are still struggling to keep up with the new international scene. Some of these countries, such as Brazil, have very important livestock industries and are key to the global food systems. Over the last two decades, Brazil became a leading player in exports of livestock products, including poultry, and this created a strong pressure on the national veterinary services to respond to trade demands, leading to focus animal health policies on the export-driven sector. During the same period, Brazil has gone a long way in the direction of integrating epidemiology with veterinary services. Epidemiology groups grew at main universities and have been working with government to provide support to animal health policy. The scope and quality of the applied epidemiological work improved and focused on complex data analysis and development of technologies and tools to solve specific disease problems. Many public veterinary officers were trained in modern epidemiological methods. However, there are important institutional bottlenecks that limit the impact of epidemiology in evidence-based decision making. More complex challenges require high levels of expertise in veterinary epidemiology, as well as institutional models that provide an appropriate environment for building and sustaining capacity in national veterinary services. Integrating epidemiology with animal health policy is a great opportunity if epidemiologists can understand the real issues, including the socio-economic dimensions of disease management, and focus on innovation and production of knowledge. It may be a trap if epidemiologists are restricted to answering specific decision-making questions and policy makers perceive their role exclusively as data analysts or providers of technological solutions. Fostering solutions for complex issues is key to successful integration with policy making.

An epidemiological approach to welfare research in zoos: the Elephant Welfare Project.

Multi-institutional studies of welfare have proven to be valuable in zoos but are hampered by limited sample sizes and difficulty in evaluating more than just a few welfare indicators. To more clearly understand how interactions of husbandry factors influence the interrelationships among welfare outcomes, epidemiological approaches are needed as well as multifactorial assessments of welfare. Many questions have been raised about the housing and care of elephants in zoos and whether their environmental and social needs are being met in a manner that promotes good welfare. This article describes the background and rationale for a large-scale study of elephant welfare in North American zoos funded by the (U.S.) Institute of Museum and Library Services. The goals of this project are to document the prevalence of positive and negative welfare states in 291 elephants exhibited in 72 Association of Zoos and Aquariums zoos and then determine the environmental, management, and husbandry factors that impact elephant welfare. This research is the largest scale nonhuman animal welfare project ever undertaken by the zoo community, and the scope of environmental variables and welfare outcomes measured is unprecedented.

Evaluation of the pooling of swabs for real-time PCR detection of low titre shedding of low pathogenicity avian influenza in turkeys.

The purpose of this study was to determine whether pooling avian influenza (AI)-positive swabs with negative swabs has a detrimental effect on the sensitivity of AI real-time reverse transcription-polymerase chain reactions (rRT-PCRs). Cloacal and buccal swabs were sampled daily from 12 turkeys infected with A/goose/England/07(H2N2). For half the turkeys, each swab was mixed with four swabs from known AI-negative turkeys, and for the other half the swabs were tested individually. Bayesian modelling was used to (i) determine whether pooling the positive swabs compromised the cycle threshold (C(t)) value obtained from the rRT-PCRs, and (ii) estimate the likelihood of detection of an H2N2 infected turkey flock via rRT-PCR for pooled and individually tested swabs (cloacal and buccal) vs. the number of days post-infection of the flock. Results indicated that there was no significant effect of compromising AI rRT-PCR sensitivity by pooling a weak positive swab with negative swabs on the Ct values which were obtained. Pooled sampling was able to widen the detection window compared to individual sampling, for the same number of rRT-PCR tests. This indicates that pooled sampling would be an effective method of reducing the number of tests to be performed to determine flock status during an AI outbreak and for surveillance.

A novel approach to real-time risk prediction for emerging infectious diseases: a case study in Avian Influenza H5N1.

Mathematical simulation modelling of epidemic processes has recently become a popular tool in guiding policy decisions for potential disease outbreaks. Such models all rely on various parameters in order to specify quantities such as transmission and detection rates. However, the values of these parameters are peculiar to an individual outbreak, and estimating them in advance of an epidemic has been the major difficulty in the predictive credibility of such approaches. The obstruction to classical approaches in estimating model parameters has been that of missing data: (i) an infected individual is only detected after the onset of clinical signs, we never observe the time of infection directly; (ii) if we wish to make inference on an epidemic while it is in progress (in order to predict how it might unfold in the future), we must take into account the fact that there may be individuals who are infected but not yet detected. In this paper we apply a reversible-jump Markov chain Monte Carlo algorithm to a combined spatial and contact network model constructed in a Bayesian context to provide a real-time risk prediction during an epidemic. Using the example of a potential Avian H5N1 epidemic in the UK poultry industry, we demonstrate how such a technique can be used to give real-time predictions of quantities such as the probability of individual poultry holdings becoming infected, the risk that individual holdings pose to the population if they become infected, and the number and whereabouts of infected, but not yet detected, holdings. Since the methodology generalises easily to many epidemic situations, we anticipate its use as a real-time decision-support tool for targetting disease control to critical transmission processes, and for monitoring the efficacy of current control policy.

Statistical approaches to the monitoring and surveillance of infectious diseases for veterinary public health.

This paper covers the aspect of using statistical methodology for the monitoring and surveillance of routinely collected data in veterinary public health. An account of the Farrington algorithm and Poisson cumulative sum schemes for the prospective detection of aberrations is given with special attention devoted to the occurrence of seasonality and spatial aggregation of the time series. Modelling approaches for retrospective analysis of surveillance counts are also described. To illustrate the applicability of the methodology in veterinary public health, data from the monitoring of rabies among fox in Hesse, Germany, are analysed.

Using data collected for production or economic purposes to research production animal welfare: an epidemiological approach.

Epidemiologists use the analyses of large data sets collected for production or economic purposes to research production nonhuman animal welfare issues in the commercial setting. This approach is particularly useful if the welfare issue is rare or hard to reproduce. However, to ensure the information is accurate, it is essential to carefully validate these data. The study used economic data to research in-transit deaths of finishing pigs. The most appropriate model to fit the distribution of the outcome must be selected. A negative binomial model fit these data because the prevalence was low and most lots of pigs had no deaths. The study used hierarchical dummy variables to identify thresholds of temperature and humidity above which in-transit losses increased. Multiple variable modeling provides the foundation for the strength of epidemiological research. The model identifies the association between each factor and the outcome after controlling for the other factors in the model. The study evaluated confounding and interaction. Bias may be introduced when data are limited to one farm system, one abattoir, or one season. Census data enable us to understand the entire industry.

Basic epidemiologic concepts related to assessment of animal health and performance.

Modern animal production systems are increasingly complex,which is why farmers depend on veterinarians to help them make sound decisions based on valid interpretation of data. While serving as advisors to farmers, veterinarians face the challenge of properly identifying key indicators of animal performance and differentiating between values that reflect normal biologic variation and those that require intervention. The veterinary consultant must understand the strengths and weaknesses of data, assess production trends accurately, and evaluate the results of management changes. This article describes some basic epidemiologic concepts about animal performance data. These concepts equip veterinary practitioners with the tools they need to give the best advice.

Disease outbreak investigation in food animal practice.

In addition to excellent observation skills and a good understanding of production medicine, veterinarians require the tools of epidemiology for the successful investigation of disease outbreaks. Food supply veterinary practitioners are often called upon to investigate various types of disease outbreaks. In this article, the authors outline the primary questions a practitioner should address and summarize a systematic approach to determining the causes of an outbreak and minimizing further losses. The investigation of disease outbreaks provides an opportunity for the herd veterinarian to show clients the advantages of a herd health program and the value of a good record-keeping system.

Modelling the potential impact of exotic diseases on regional Australia.

Recent international initiatives for disease control suggest that, in the future, the consequences for trade of an exotic disease outbreak may not be as severe as estimated in the past. If zoning were to be accepted by Australia's trading partners, then the major effects may be felt at the regional rather than the national level. A study, using an integrated epidemiological/economic model, was undertaken to compare the impacts of 3 important exotic diseases (foot-and-mouth disease, classical swine fever and sheep pox) in 3 different regions of Australia. The study demonstrated that there are significant differences between the size and effect of different disease outbreaks. Regional factors influence not only the way that the disease will spread and manifest itself, but also the effects on local communities. Foot-and-mouth disease caused more economic losses than sheep pox or classical swine fever. The major determinant of differences in the effects of the diseases between regions was the nature of the regional economies. The less diversified the economy, the greater the effect of an exotic disease outbreak in relation to the size of that economy.

Modelling the dynamics and economics of health in individual dairy herds: future tasks for the veterinarian in practice and in research.

Collaboration with practicing veterinarians was established in a research project and has resulted in several epidemiologic tools to assist them in their work. Simultaneously, the research group obtained continuous access to valid and precise data and obtained first-hand knowledge about real-life problems for the dairy farmer and the practicing veterinarian. The veterinarian was able to supply detailed information concerning managerial routines applied on the farm. Epidemiologic analyses of the collected data produced input for herd-specific modelling of herd dynamic and economic effects of relevant production alternatives by means of a dynamic, stochastic, and mechanistic simulation model. The relevance of this approach as a research methodology is discussed.