Malaria hotspots explained from the perspective of ecological theory underlying insect foraging

Yared Debebe,Rickard Ignell,Sharon Rose Hill,Sisay Dugassa,Richard J Hopkins,Habte Tekie

doi:10.1038/s41598-020-78021-x

Abstract

Hotspots constitute the major reservoir for residual malaria transmission, with higher malaria incidence than neighbouring areas, and therefore, have the potential to form the cornerstone for successful intervention strategies. Detection of malaria hotspots is hampered by their heterogenous spatial distribution, and the laborious nature and low sensitivity of the current methods used to assess transmission intensity. We adopt ecological theory underlying foraging in herbivorous insects to vector mosquito host seeking and modelling of fine-scale landscape features at the village level. The overall effect of environmental variables on the density of indoor mosquitoes, sporozoite infected mosquitoes, and malaria incidence, was determined using generalized linear models. Spatial analyses were used to identify hotspots for malaria incidence, as well as malaria vector density and associated sporozoite prevalence. We identify household occupancy and location as the main predictors of vector density, entomological inoculation rate and malaria incidence. We propose that the use of conventional vector control and malaria interventions, integrated with their intensified application targeting predicted hotspots, can be used to reduce malaria incidence in endemic and residual malaria settings.

Highlights

Hotspots constitute the major reservoir for residual malaria transmission, with higher malaria incidence than neighbouring areas, and have the potential to form the cornerstone for successful intervention strategies
We propose that the use of conventional vector control and malaria interventions, integrated with their intensified application targeting predicted hotspots, can be used to reduce malaria incidence in endemic and residual malaria settings
Insect-plant interactions provide the theoretical framework by which vector density and malaria prevalence can be modelled in a heterogeneous local landscape

Summary

Introduction

Hotspots constitute the major reservoir for residual malaria transmission, with higher malaria incidence than neighbouring areas, and have the potential to form the cornerstone for successful intervention strategies. Hotspots constitute the major reservoir for persistent malaria transmission and are associated with higher vector density, sporozoite prevalence and malaria incidence than neighbouring areas[9,12]. Malaria transmission in these hotspots has been suggested to be primarily driven by local environmental conditions, e.g., proximity to vector breeding s ites[10,13,14], vegetation c over[15,16], housing structure and condition[17,18,19], bed net use[20,21], and household occupancy[22]. There is no consensus as to which factors underlie the formation of hotspots at the village level, and the identification of these is crucial to attain the Sustainable Development Goal of zero malaria incidence level in a given area[23,24]

Methods

Results

Conclusion