Modeling the impact of non-human host predation on the transmission of Chagas disease

In addition to the traditional transmission route via the biting-and-defecating process, non-human host predation of triatomines is recognized as another significant avenue for Chagas disease transmission. In this paper, we develop an eco-epidemiological model to investigate the impact of predation on the disease's spread. Two critical thresholds, R_v^p (the basic reproduction number of triatomines) and R₀^p (the basic reproduction number of the Chagas parasite), are derived to delineate the model's dynamics. Through the construction of appropriate Lyapunov functions and the application of the Bendixson-Dulac theorem, the global asymptotic stabilities of the equilibria are fully established. The vector-free equilibrium E₀ is globally stable when R_v^p<1. E₁, the disease-free equilibrium, is globally stable when R_v^p>1 and R₀^p<1, while the endemic equilibrium E^∗ is globally stable when both R_v^p>1 and R₀^p>1. Numerical simulations highlight that the degree of host predation on triatomines, influenced by non-human hosts activities, can variably increase or decrease the Chagas disease transmission risk. Specifically, low or high levels of host predation can reduce R₀^p to below unity, while intermediate levels may increase the infected host populations, albeit with a reduction in R₀^p. These findings highlight the role played by non-human hosts and offer crucial insights for the prevention and control of Chagas disease.