Vector diversity and malaria prevalence: global trends and local determinants

Identifying determinants of global infectious disease burden is a central goal of disease ecology. While it is widely accepted that host diversity structures parasite diversity and disease prevalence, the influence of diversity in vectors-obligatory intermediate hosts for many parasites-has rarely been examined. Malaria, for instance, can be transmitted by over 70 mosquito species, but the impact of this diversity on malaria risk remains unclear. Further, environmental factors, like temperature, may modify this impact by influencing arthropod life history and behaviour. We studied the relationship between vector diversity, malaria prevalence and environmental attributes by curating and analysing data from open-access sources. Globally, the association between vector species richness and malaria prevalence differed by latitude, indicating strong dependence on environmental conditions. Processes by which the environment impacts vector community assemblage and function, and subsequently disease prevalence, varied across regions. In Africa, the environment exerted a top-down influence on disease by shaping vector communities, whereas in Southeast Asia, disease prevalence depended on more complex interactions between the physical and socioeconomic environment (rainfall and GDP) and vector diversity. This work highlights the role of vector diversity in structuring disease distribution and offers insights to disease macroecology theory.