The interplay between temperature, Trypanosoma cruzi parasite load, and nutrition: Their effects on the development and life-cycle of the Chagas disease vector Rhodnius prolixus.

Chagas disease, caused by the protozoan parasite Trypanosoma cruzi transmitted by blood-sucking insects of the subfamily Triatominae, is a major neglected tropical disease affecting 6 to 7 million of people worldwide. Rhodnius prolixus, one of the most important vectors of Chagas disease in Latin America, is known to be highly sensitive to environmental factors, including temperature. This study aimed to investigate the effects of different temperatures on R. prolixus development and life-cycle, its relationship with T. cruzi, and to gather information about the nutritional habits and energy consumption of R. prolixus. We exposed uninfected and infected R. prolixus to four different temperatures ranging from 24°C to 30°C, and monitored their survival, developmental rate, body and blood meal masses, urine production, and the temporal dynamics of parasite concentration in the excreted urine of the triatomines over the course of their development. Our results demonstrate that temperature significantly impacts R. prolixus development, life-cycle and their relationship with T. cruzi, as R. prolixus exposed to higher temperatures had a shorter developmental time and a higher mortality rate compared to those exposed to lower temperatures, as well as a lower ability to retain weight between blood meals. Infection also decreased the capacity of the triatomines to retain weight gained by blood-feeding to the next developmental stage, and this effect was proportional to parasite concentration in excreted urine. We also showed that T. cruzi multiplication varied depending on temperature, with the lowest temperature having the lowest parasite load. Our findings provide important insights into the potential impact of climate change on the epidemiology of Chagas disease, and can contribute to efforts to model the future distribution of this disease. Our study also raises new questions, highlighting the need for further research in order to understand the complex interactions between temperature, vector biology, and parasite transmission. Author summary: Chagas disease, caused by the parasite Trypanosoma cruzi and transmitted by blood-sucking kissing bugs, is a major neglected tropical disease affecting millions of people worldwide. The insect vector Rhodnius prolixus is highly sensitive to environmental factors, including temperature. In this study, we investigated the effects of different temperatures on R. prolixus and its interaction with T. cruzi, as well as the nutritional habits and energy consumption of the vector. We exposed uninfected and infected insects to various temperatures, and monitored their survival, development, body and blood meal weights, urine production, and T. cruzi infection over their lifespan. Our results revealed that temperature significantly influenced R. prolixus development, life-cycle, and its interaction with T. cruzi. Insects exposed to higher temperatures had shorter development time, increased mortality, and reduced ability to maintain weight. Infection further compromised the ability of the triatomines to retain weight gained by blood-feeding, and this effect correlated with parasite load. Additionally, T. cruzi multiplication varied with temperature, with lower temperatures associated with lower parasite concentration. Our findings have important implications for understanding the impact of climate change on Chagas disease epidemiology and contribute to modeling its future spread. [ABSTRACT FROM AUTHOR]