Integrating landscape ecology and epidemiology
Résumé
Biological mechanisms known to affect space-time dynamics of infectious diseases may be impacted by ecosystem change and the last 50 years have seen the greatest changes in ecosystem structure and function in human history (Patz and Confalonieri 2005). Alveolar echinococcosis (AE) is a disease lethal to humans caused by a Cestod parasite. The parasite is transmitted through a life-cycle including small mammal intermediate hosts (rodents and lagomorphs) and carnivore definitive hosts, mostly foxes and domestic dogs. Over the last 15 years it appears that the parasite has spread its geographic range in the red fox populations of western and eastern Europe and large foci of AE have been discovered in Western China at the Eastern border of the Tibetan plateau. Transmission systems have been studied in eastern France and Western China combining quantified analysis of landscape changes, small mammal communities and AE prevalence in humans and foxes (Giraudoux et al. 2002; Giraudoux et al. 2006). Evidence has been provided that at the regional scale landscape can affect human disease distribution through interaction with small mammal communities and their population dynamics. Regional models have been proposed where satellite imagery was used to describe landscapes and evaluate transmission risk. Here we review those studies and discuss their results with perspectives for studies of pathogenic organism transmission grounded on systems approach and landscape ecology concepts.