Day-to-Day Population Movement and the Management of Dengue Epidemics.

Jorge A Falcón-Lezama,Ben Adams,José Ramos-Castañeda,Ruth A Martínez-Vega,Pablo A Kuri-Morales

doi:10.1007/s11538-016-0209-6

Abstract

Dengue is a growing public health problem in tropical and subtropical cities. It is transmitted by mosquitoes, and the main strategy for epidemic prevention and control is insecticide fumigation. Effective management is, however, proving elusive. People’s day-to-day movement about the city is believed to be an important factor in the epidemiological dynamics. We use a simple model to examine the fundamental roles of broad demographic and spatial structures in epidemic initiation, growth and control. We show that the key factors are local dilution, characterised by the vector–host ratio, and spatial connectivity, characterised by the extent of habitually variable movement patterns. Epidemic risk in the population is driven by the demographic groups that frequent the areas with the highest vector–host ratio, even if they only spend some of their time there. Synchronisation of epidemic trajectories in different demographic groups is governed by the vector–host ratios to which they are exposed and the strength of connectivity. Strategies for epidemic prevention and management may be made more effective if they take into account the fluctuating landscape of transmission intensity associated with spatial heterogeneity in the vector–host ratio and people’s day-to-day movement patterns.Electronic supplementary materialThe online version of this article (doi:10.1007/s11538-016-0209-6) contains supplementary material, which is available to authorized users.

Highlights

Dengue fever is the most important mosquito-borne viral disease in the world
We develop a mathematical model to improve our understanding of how quotidian urban movement behaviour contributes to the risk of dengue epidemics, and the epidemic trajectories when they do occur, and consider transmission control strategies that account for these patterns
The model population is structured into two non-mixing ‘local’ subpopulations, each composed of non-mobile (N Mi ) residents in Hi and non-mixing commuters (N Ci ) moving between Hi and Si

Summary

Introduction

Dengue fever is the most important mosquito-borne viral disease in the world. It is caused by infection with any of the four serotypes of dengue virus. An infected vector transmits the virus to a susceptible host who, after an intrinsic incubation period, transmits the virus to another vector which, following an extrinsic incubation period, starts a new cycle. This process is, influenced by numerous factors including climate variation, human migration, immune cross-reaction, vertical transmission and widespread asymptomatic, but transmissible, infection (Adams et al 2006; Kyle and Harris 2008; Adams and Boots 2010; Descloux et al 2012; Yoon et al 2012; Rabaa et al 2013). We develop a mathematical model to improve our understanding of how quotidian urban movement behaviour contributes to the risk of dengue epidemics, and the epidemic trajectories when they do occur, and consider transmission control strategies that account for these patterns

Objectives

Results

Conclusion