89

La dengue est une infection virale à transmission vectorielle qui touche, pour l’instant, essentiellement les pays de la zone tropicale et subtropicale. Nous développons un cadre systémique et complexe pour l’étude de cette maladie, qui permet à la fois de décomposer ses différentes entités – hôte, vecteur, virus, environnement – tout en affirmant le poids de leurs interactions dans ses dynamiques potentielles. L’étude de cette complexité systémique s’enrichit d’un cadre méthodologique qui permet d’intégrer dans un même modèle des dynamiques biologiques et sociales, dans des environnements changeants. Ce cadre de recherche implique de nouvelles pratiques, il rend indispensable une collaboration étroite des sciences sociales, environnementales, biologiques et informatiques, sans oublier l’implication des populations et des acteurs locaux de santé publique.

Dengue, a complex diseaseDengue is a widespread mosquito-borne viral infection in tropical and subtropical countries causing an estimated 500 million infections per year of which more than 20,000 result in severe disease. Since the 1970s dengue has spread and become endemic in more than 100 countries and there is concern that dengue will spread into temperate regions. The peridomestic niche of the primary mosquito vector, Aedes aegypti, results in dengue being a largely urban and periurban disease where the high population densities cause major epidemics. Although a number of risk factors have been identified at different spatial scales of analysis, their general relevance is debatable. Very local scale environmental factors can determine both the abundance of mosquitoes and their ability to transmit the virus. Thus the environmental complexity of urban settings coupled with heterogeneity in human population density yield potentially complex interactions in highly differentiated local conditions that are difficult to assess. We are developing a complex framework to enable a more tractable understanding of dengue epidemiology. This framework enables the disentanglement of actors, host, vector, virus and environment, all the while asserting the dynamic contribution of their interactions. The study of this complexity is enriched by a methodological framework that integrates the biological and social dynamics in changing environments in a single model. The first section of the article describes the complexity of dengue epidemiology. The second section proposes multiagent spatial modelling as a methodological framework with which to integrate this complexity.