Identifying sources and sinks of vector-borne zoonoses across gradients of anthropogenic disturbance: Implications for disease prevention and control
Many vector-borne zoonotic pathogens have transmission systems that can be characterized in a metapopulation framework, because vectors often comprise spatially discrete populations of the same species that are linked by dispersal. Related to these vector metapopulations are complex networks of host-parasite-vector interactions. Understanding the scale at which parasite transmission and vector metapopulations are maintained across a landscape is important for the identification of and targeted control of transmission ‘hotspots’. In this study, we apply a hierarchical source-sink network modeling framework to the Attalea butyracea palm-Rhodnius pallescens vector-Trypanosoma cruzi system that predominates in rural Panama. T. cruzi is the cause of Chagas disease in humans, which is a major cause of human morbidity, mortality, and DALYs (disability adjusted life years) in Latin America. We parameterize this model using data from field studies of vector population structure, trypanosome infection, host blood meal analysis, and experimental studies of vector dispersal ability.
We identify pathogen and vector ‘source’ populations at the individual palm level that are major contributors to vector abundance and infection at the habitat and landscape scale. Principal hotspots, or sources for vector abundance and pathogen transmission appear to be in peridomestic palms and palms in riparian forest remnants. Ultimately, our goal is to use this modeling framework to pinpoint sources of infection across a landscape and to test potential environmental control strategies for preventing human transmission.