The unapparent effect of climate forcing on urban amoebiasis in Mexico City

Abstract

AbstractDespite advances in the provision of sanitation infrastructure in cities, diarrheal-related illnesses continue to be a global burden. In cities of the developing world, explanations for the persistence of diarrheal-related diseases revolve around the role of sanitation, poverty, and individual behavior. Less is known about the role of climate in forcing the inter-annual variability of transmission. We quantified the contribution of rainfall to the transmission of a diarrhoeal disease caused by the protozoan Entamoeba histolytica. We formulated a process-based model of the population dynamics of Entamoeba histolytica in 6 municipalities of Mexico City, and we reconstructed the interannual variability of the observed cases of amebiasis between 2005 and 2012. Using inference methods for non-linear systems, we estimated that 10% of the susceptible individuals were infected in early 2005 and 90% of those infections were causally related to the exposure to the environmental stage of the pathogen after rainfall events. The magnitude of these results underscores the importance of considering the interaction between climate forcing and water management as ecological determinants of health in megacities.