Modeling the Impacts of Predation and Biodiversity Loss on the Transmission of Malaria in Madagascar

Abstract

As a major cause of morbidity and mortality, malaria has a significant burden on human global health, especially in developing countries. In recent decades, human-derived changes to the environment have adversely affected biodiversity and its ecosystem services to human populations, including the potential reduction of disease transmission. For vector-borne diseases such as malaria, biodiversity loss may increase disease transmission if it reduces predation on vectors, thereby increasing their density. However, few studies have examined the interactions of biodiversity, predation, and disease transmission in a specific disease system, and the dynamics of vector-borne diseases are challenging to study through field work. Therefore, the purpose of this research is to model the impacts of predation and biodiversity loss on the transmission of malaria in Madagascar, specifically focusing on mosquito predation by insectivorous bats in Ranomafana National Park. As an extension of the Ross-Macdonald malaria model and Moore predation model, the mathematical model created for this study examines the effects of a vector’s predator on malaria transmission in hosts by incorporating both vector and predator dynamics. The results of this model demonstrate that predation by insectivorous bats can naturally control the vector population, reducing the prevalence of malaria in hosts and vectors. Further, predation also favors clinical immunity in the host population, supporting an endemic disease state. On the other hand, a natural system with fewer insectivorous bats has an increased prevalence of malaria infection in the host and vector populations. Therefore, maintaining the biodiversity of insectivorous bats is beneficial for human health. Ultimately, the potential benefit of biodiversity on human health can not only unite public health and conservation, but also incentivize methods for disease control and the protection of biodiversity.