Land-use planning for health: Tradeoffs and nonlinearities govern how land-use change impacts vector-borne disease risk

Abstract

Patterns of land-use can affect the transmission of many infectious diseases with human health implications; yet, applied ecosystem service models have rarely accounted for disease transmission risk. A mechanistic understanding of how land-use changes alter infectious disease transmission would help to target public health interventions and to minimize human risk of disease with either ecosystem degradation or restoration. Here, we present a spatially explicit model of disease transmission on heterogeneous landscapes that is designed to serve as a road map for modeling the multifaceted impacts of land-use on disease transmission. We model the transmission of three vector-borne diseases with distinct transmission dynamics (parameterized using published literature to represent dengue, yellow fever, and malaria) on simulated landscapes of varying spatial heterogeneity in tree cover and urban area. Overall, we find that these three diseases depend on the biophysical landscape in different nonlinear ways, leading to tradeoffs in disease risk across the landscape; rarely do we predict disease risk to be high for all three diseases in a local setting. We predict that dengue risk peaks in areas of high urban intensity and human population density, yellow fever risk peaks in areas with low to moderate human population density and high tree cover, and malaria risk peaks where patchy tree cover abuts urban area. To examine how this approach can inform land use planning, we applied the model to a small landscape to the northwest of Bogota, Colombia under multiple restoration scenarios. We predict that in an area inhabited by both Aedes aegypti and Ae. albopictus, any increase in overall tree cover would increase dengue and yellow fever risk, but that risk can be minimized by pursuing a large contiguous reforestation project as opposed to many small, patchy projects. A large contiguous reforestation project is also able to both reduce overall malaria risk and the number of malaria hotspots. As sustainable development goals make ecosystem restoration and biodiversity conservation top priorities, it is imperative that land use planning account for potential impacts on both disease transmission and other ecosystem services. Open Research statementAll data and code used in this study are available in the online supplemental material. Code and data are also hosted at: https://github.com/morgankain/Land-Use_Disease_Model.