Optimal control for disease vector management in SIT models: an integrodifference equation approach

Klodeta Kura,Claire El Mouden,Michael B Bonsall,Doran Khamis

doi:10.1007/s00285-019-01327-6

Klodeta Kura, Claire El Mouden + Show 2 more

Open Access

https://doi.org/10.1007/s00285-019-01327-6

Copy DOI

Abstract

Vector-borne diseases are a major public health concern inflicting high levels of disease morbidity and mortality. Vector control is one of the principal methods available to manage infectious disease burden. One approach, releasing modified vectors (such as sterile or GM mosquitoes) Into the wild population has been suggested as an effective method of vector control. However, the effects of dispersal and the spatial distribution of disease vectors (such as mosquitoes) remain poorly studied. Here, we develop a novel mathematical framework using an integrodifference equation (discrete in time and continuous in space) approach to understand the impact of releasing sterile insects into the wild population in a spatially explicit environment. We prove that an optimal release strategy exists and show how it may be characterized by defining a sensitivity variable and an adjoint system. Using simulations, we show that the optimal strategy depends on the spatially varying carrying capacity of the environment.

Highlights

Vector borne diseases are a major public health concern, causing high levels of morbidity and leading to nearly one million deaths, annually (WHO 2016)
An early example is that developed by Manoranjan and van den Driessche (1986) who analysed the effect of non-uniform sterile insect releases in a heterogeneous environment
Spatial spread is a key element in mosquito reproduction and some studies argue that sterile insect technique (SIT) technique may not be very effective in controlling mosquito populations due to their dispersal and distribution (Ferreira et al 2008). To address this issue we present an alternative modelling framework that allows us to consider population dynamic outcomes associated with different dispersal behaviour

Summary

Introduction

Vector borne diseases are a major public health concern, causing high levels of morbidity and leading to nearly one million deaths, annually (WHO 2016). The sterile insect technique (SIT) is a well established empirical method for reducing population size This technique has been widely used to suppress or eradicate many insect pest species, through the release of modified insects (lab-sterilised, irradiated and/or novel genetic technologies) (Alphey et al 2010). An early example is that developed by Manoranjan and van den Driessche (1986) who analysed the effect of non-uniform sterile insect releases in a heterogeneous environment. Another modelling approach explored considered random releases across the environment and concluded that the effectiveness of SIT is highly influenced by spatial heterogeneity (Ferreira et al 2008). They concluded that uniform releases are more effective than releasing at specific locations

Objectives

Results

Conclusion