Adapting to vector-borne diseases under climate change : an evidence-informed approach

Les preuves s'accumulent sur les effets des changements climatiques. Étant donné leurs impacts sur la santé, en particulier sur les maladies à transmission vectorielle, il est nécessaire de concevoir des stratégies efficaces pour adapter les programmes de gestion de risque de ces maladies. Les changements climatiques constituent un problème complexe, impliquant de multiples parties prenantes et comportant beaucoup d’inconnues. Des approches qui prennent en compte cette complexité sont ainsi nécessaires afin de faire avancer la recherche sur l'adaptation aux changements climatique basée autant sur des données scientifiques que sur des données provenant de différents intervenants. Les approches fondées sur les données probantes sont de plus en plus recherchées dans les politiques de santé et la prise de décisions, dans le but d'améliorer la santé des populations. Ces approches sont apparues en réaction aux approches improvisées, développées suite aux crises liées aux problèmes de santé publique. Elles doivent être systématiques et transparentes, et faire appel aux meilleures preuves disponibles. L'aide à la décision multicritère délibérative constitue une de ces approches. L'objectif de cette thèse était d'étudier les principales préoccupations en matière de décisions relatives à l'adaptation au risque des maladies vectorielles influencées par les changements climatiques dans deux contextes : le Québec, où les maladies vectorielles sont présentes, mais ne constituent pas la principale préoccupation, et le Burkina Faso, où les maladies vectorielles sont au contraire très préoccupantes. Les fondements théoriques de cette étude sont basés sur la science post-normale, l'adaptation aux changements climatiques et une approche d'analyse de décision multicritère. La recherche sur l'adaptation aux changements climatiques vise à influencer les politiques cherchant à réduire les risques et les impacts associés à ces changements. Dans ce cadre et dans le contexte de l'adaptation aux maladies vectorielles, trois questions clés se posent : 1) de quelles maladies nous préoccupons-nous ? 2) qui est le plus vulnérable à ces maladies ? et 3) quelles sont les mesures recommandées pour s'adapter à ces maladies ? Cette thèse contribuera à répondre à ces trois questions dans le but de faire avancer l'adaptation face aux maladies vectorielles. Pour répondre à la première question, nous avons identifié des préoccupations d'importance pour la priorisation des maladies liées aux changements climatiques au Québec et au Burkina Faso grâce à l’utilisation d’une approche délibérative multicritère d'aide à la décision. Les résultats ont démontré que, alors que des préoccupations générales sont partagées entre ces deux régions, des préoccupations plus spécifiques aux maladies diffèrent quant à elles selon le contexte, tant sur des aspects scientifiques que sur d’autres aspects partagés par les parties prenantes. Pour répondre à la deuxième question, les connaissances actuelles et les comportements de la population québécoise quant au virus du Nil occidental ont été explorés, comme étape préliminaire pour évaluer la capacité d'adaptation au risque de maladies causées par les moustiques. Nous avons considéré que la réponse au risque perçu de maladies transmises par les moustiques constituait une forme d'adaptation. Les résultats ont montré que les connaissances globales et les niveaux d'adoption comportementale sont bons et qu’il existe au moins quatre sous-groupes différents dans la population caractérisés par différents facteurs associés à l'adoption de comportements préventifs. Enfin, pour répondre à la troisième question, une approche multicritère délibérative a été utilisée pour examiner les stratégies de gestion du virus du Nil occidental au Québec, dans le cadre théorique d’une transmission accrue, et les stratégies de gestion du paludisme au Burkina Faso, dans le cadre de la transmission actuelle. De manière analogue au modèle développé pour la priorisation des maladies, cette comparaison entre les deux régions et les contextes de maladie ont permis de confirmer l’existence de préoccupations générales partagées. Cette thèse a permis de démontrer la pertinence des approches d'aide à la décision pour explorer des stratégies de gestion efficaces basées sur l'expérience des intervenants et les meilleures preuves scientifiques disponibles.Evidence is accumulating on the ongoing effects of climate change. Given the anticipated health implications, notably vector-borne disease impacts, there is a need to design effective and tailored strategies to adapt to vector-borne disease risk. Climate change is a complex problem, involving multiple stakeholders and many unknowns. As such, approaches that can embrace this complexity are needed to inform adaptation research with evidence - both scientific and stakeholder-informed. Evidence-informed approaches are being increasingly sought in health policy and decision-making in order to improve population health. Evidence-informed approaches have arisen in reaction to ad-hoc, crisis-driven responses to health problems. They recognize the need to be systematic and transparent, and make use of the best available evidence. Deliberative multicriteria decision aid is one such approach. The objective of this thesis was to study key decision concerns of importance in adapting to vector-borne disease risk under climate change in two contexts: Quebec, where vector-borne diseases are present but not the main burden of disease, and Burkina Faso, where vector-borne diseases contribute to the primary burden of disease. The theoretical underpinnings of this study are rooted in post-normal science, climate change adaptation, and a multicriteria decision analysis approach. Climate change adaptation research is aimed at informing policies to reduce risks and impacts associated with climate change. Within this framework, and in the context of vector-borne disease adaptation, three key questions arise: 1) what diseases are we concerned about? 2) who is most vulnerable and at risk to these diseases? and 3) what are recommended measures to adapt to these diseases? This thesis contributes to these three dimensions to inform adaptation to vector-borne disease. With regards to the first question, we identified concerns of importance for disease prioritization under climate change in both Quebec and Burkina Faso using a deliberative multi-criteria decision aid approach. The results showed that general concerns are shared among these contrasting contexts while specific disease priorities differ as a result of context-informed evidence – both scientific and stakeholder-shared. With regards to the second question, current knowledge and readiness of the Quebec population relative to West Nile virus was explored as a preliminary and integral step to assessing adaptive capacity to mosquito-borne disease risk. Here, response to perceived mosquito-borne disease risk constitutes a form of adaptation. The results showed that overall knowledge and behavioural adoption levels are good though at least four different subgroups exist within the population with different factors associated with preventive behaviour adoption. Finally, with respect to the third question, a deliberative multi-criteria approach was used to examine management strategies for West Nile virus in Quebec and malaria in Burkina Faso. West Nile virus strategies under current and theoretical increased transmission were explored in Quebec, and malaria management strategies under current transmission were explored in Burkina Faso. Analogously to the model developed for disease prioritization, shared general concerns were found between the contrasting country and disease contexts lending support to the practical applications of decision-aid approaches for exploring effective management strategies informed by stakeholder experience and the best available scientific evidence

Spatially explicit multi-criteria decision analysis for managing vector-borne diseases

The complex epidemiology of vector-borne diseases creates significant challenges in the design and delivery of prevention and control strategies, especially in light of rapid social and environmental changes. Spatial models for predicting disease risk based on environmental factors such as climate and landscape have been developed for a number of important vector-borne diseases. The resulting risk maps have proven value for highlighting areas for targeting public health programs. However, these methods generally only offer technical information on the spatial distribution of disease risk itself, which may be incomplete for making decisions in a complex situation. In prioritizing surveillance and intervention strategies, decision-makers often also need to consider spatially explicit information on other important dimensions, such as the regional specificity of public acceptance, population vulnerability, resource availability, intervention effectiveness, and land use. There is a need for a unified strategy for supporting public health decision making that integrates available data for assessing spatially explicit disease risk, with other criteria, to implement effective prevention and control strategies. Multi-criteria decision analysis (MCDA) is a decision support tool that allows for the consideration of diverse quantitative and qualitative criteria using both data-driven and qualitative indicators for evaluating alternative strategies with transparency and stakeholder participation. Here we propose a MCDA-based approach to the development of geospatial models and spatially explicit decision support tools for the management of vector-borne diseases. We describe the conceptual framework that MCDA offers as well as technical considerations, approaches to implementation and expected outcomes. We conclude that MCDA is a powerful tool that offers tremendous potential for use in public health decision-making in general and vector-borne disease management in particular

Climate change and mosquito-borne arboviruses: an examination of current and future potential range changes of «Culex pipiens» in Canada

Given current and projected climate change, the range distribution of a number of species, including mosquito vectors, is anticipated to shift geographically with implications for the transmission dynamics of vector-borne diseases carried by specialized species. This thesis examines the risk factors for human incidence of mosquito-borne disease in Canada and characterizes the climatic determinants of the current range distribution of Culex pipiens, a known mosquito vector of arboviruses found in Canada. Spatial statistical models were developed from mosquito surveillance data collected by Canadian provinces over the last decade and are used to give an estimation of the current habitat suitability of this species in Canada. Habitat suitability for Culex pipiens under projected climate change is also examined for three future time periods. Results predict a significant range expansion of Culex pipiens' suitable habitat northward into the year 2100 with potential implications for disease transmission resulting from changing biodiversity within communities.Selon les changements climatiques prévus, on anticipe un déplacement de la distribution géographique de nombreuses espèces, dont les moustiques porteurs, ce qui provoquerait des répercussions sur la dynamique des maladies à transmission vectorielle. La présente thèse porte sur les répercussions humaines des éléments de risque des maladies transmises par les moustiques au Canada ainsi que sur la caractérisation des déterminants climatiques de la distribution géographique actuelle du Culex pipiens, un moustique porteur d'arbovirus au Canada. Des modèles statistiques de chorologie ont été créés grâce à des données de surveillance provenant des provinces Canadiennes au cours de la dernière décennie et grâce auxquelles il est possible d'estimer l'actuelle étendue de cette espèce au Canada. On y observe aussi, pour trois périodes de temps futures, le déplacement de la distribution géographique du Culex pipiens en tenant compte des changements climatiques prévus. Selon les résultats, on prévoit une expansion de l'étendue anticipée de l'habitat du Culex pipiens vers le nord jusqu'à l'an 2100 avec des implications pour la transmission des maladies vectorielles résultant de la biodiversité changeante au sein des communautés

Disclosure of HIV status and stigma in rural communities in Brazil: A conundrum for researchers

Stigmatization and discrimination are common consequences following disclosure of HIV serostatus; such factors are especially problematic in rural communities where “everyone knows everyone”. In this case study, researchers conducting ethnographic field studies in remote areas of Brazil decided to impersonate friends or relatives of research participants living with HIV as a means to protect participants from inadvertent disclosure of their serostatus to fellow community members. These acts of “wilful deception” raise issues about honesty and integrity in research, and how to balance issues of confidentiality with communicating research findings to communities and the broader public

Multi-Stakeholder Decision Aid for Improved Prioritization of the Public Health Impact of Climate Sensitive Infectious Diseases

The effects of climate change on infectious diseases are an important global health concern and necessitate decisions for allocation of resources. Economic tools have been used previously; however, how prioritization results might differ when done using broader considerations identified by local stakeholders has yet to be assessed. A multicriteria decision analysis (MCDA) approach was used to assess multi-stakeholder expressed concerns around disease prioritization via focus groups held in Quebec and Burkina Faso. Stakeholders weighted criteria and comparisons were made across study sites. A pilot disease prioritization was done to examine effects on disease rankings. A majority of identified criteria were common to both sites. The effect of context specific criteria and weights resulted in similar yet distinct prioritizations of diseases. The presence of consistent criteria between sites suggests that common concerns exist for prioritization; however, context-specific adjustments reveal much regarding resource availability, capacity and concerns that should be considered as this impacts disease ranking. Participatory decision aid approaches facilitate rich knowledge exchange and problem structuring. Furthermore, given multiple actors in low- and middle-income countries settings, multi-actor collaborations across non-governmental organizations, local government and community are important. Formal mechanisms such as MCDA provide means to foster consensus, shared awareness and collaboration

Criteria for the prioritization of public health interventions for climate-sensitive vector-borne diseases in Quebec

<div><p>Prioritizing resources for optimal responses to an ever growing list of existing and emerging infectious diseases represents an important challenge to public health. In the context of climate change, there is increasing anticipated variability in the occurrence of infectious diseases, notably climate-sensitive vector-borne diseases. An essential step in prioritizing efforts is to identify what considerations and concerns to take into account to guide decisions and thus set disease priorities. This study was designed to perform a comprehensive review of criteria for vector-borne disease prioritization, assess their applicability in a context of climate change with a diverse cross-section of stakeholders in order to produce a baseline list of considerations to use in this decision-making context. Differences in stakeholder choices were examined with regards to prioritization of these criteria for research, surveillance and disease prevention and control objectives. A preliminary list of criteria was identified following a review of the literature. Discussions with stakeholders were held to consolidate and validate this list of criteria and examine their effects on disease prioritization. After this validation phase, a total of 21 criteria were retained. A pilot vector-borne disease prioritization exercise was conducted using PROMETHEE to examine the effects of the retained criteria on prioritization in different intervention domains. Overall, concerns expressed by stakeholders for prioritization were well aligned with categories of criteria identified in previous prioritization studies. Weighting by category was consistent between stakeholders overall, though some significant differences were found between public health and non-public health stakeholders. From this exercise, a general model for climate-sensitive vector-borne disease prioritization has been developed that can be used as a starting point for further public health prioritization exercises relating to research, surveillance, and prevention and control interventions in a context of climate change. Multi-stakeholder engagement in prioritization can help broaden the range of criteria taken into account, offer opportunities for early identification of potential challenges and may facilitate acceptability of any resulting decisions.</p></div

Weight stability intervals in descending order from sensitivity analysis of all stakeholders for the research domain.

<p>Weight stability intervals in descending order from sensitivity analysis of all stakeholders for the research domain.</p

Criteria category weight average comparison by intervention domain.

<p>The span of stakeholder weights is indicated by the vertical lines with shaped makers indicating the intervention specific group means. Criteria categories are shown along the X axis with average weights by category shown along the Y axis. The differences between the weights given to each intervention domain (research, surveillance and prevention & control) were not found to be significantly different for any of the categories. Criteria category Legend (X axis): PHC: Public Health Criteria; SIC: Social Impact Criteria; REC: Risk and Epidemiology Criteria; AEC: Animal and Environmental Health Criteria; ECC: Economic Criteria; SOC: Strategic and Operational Criteria.</p

Article selection process for review.

<p>Article selection process for review.</p