Flight performance of trypanosome-infected Rhodnius pallescens: Implications for the spatio-temporal spread of Chagas disease in rural landscapes

Abstract

Trypanosoma cruzi is the causative agent of vector-borne Chagas disease, and is circulated within the various ecosystems of Panama through wildlife, domestic animals, and human hosts. Migration of Rhodnius pallescens, the main triatomine vector in Panama, is thought to be the primary method of spread and invasion of T. cruzi from sylvatic to domestic ecotopes. This study evaluated through two perspectives how Rhodnius pallescens’ flight performance influences the spatio-temporal spread of T. cruzi over varying environmental landscapes. First, R. pallescens flight performance was tested on a flight mill to determine if infection with T. cruzi or a closely related protozoan, T. rangeli, influenced R. pallescens’ ability to fly long-distances. Insects from all treatments flew from 0.5-5 kilometers regardless of infection status, however, insects infected with T. rangeli tended to fly longer. Second, an agent-based model of Chagas disease was used to analyze how the ecological characteristics of the landscape influence the spread of T. cruzi. My results suggests that the different vector flight ranges within 0-200 meters do not have a significant effect on the infection prevalence of the ecosystem within a single landscape type, while landscapes free of dead-end hosts and recently deforested landscapes lead to higher risks of human infection with T. cruzi. These novel findings allow for a better understanding of R. pallescens dispersal ability and peridomestic management strategies for the prevention of Chagas disease in Panama.