Dengue risk assessment using multicriteria decision analysis: A case study of Bhutan.

Tsheten Tsheten,Archie C A Clements,Darren J Gray,Kinley Wangdi,Elvina Viennet

doi:10.1371/journal.pntd.0009021

Abstract

BackgroundDengue is the most rapidly spreading vector-borne disease globally, with a 30-fold increase in global incidence over the last 50 years. In Bhutan, dengue incidence has been on the rise since 2004, with numerous outbreaks reported across the country. The aim of this study was to identify and map areas that are vulnerable to dengue in Bhutan.Methodology/Principal findingsWe conducted a multicriteria decision analysis (MCDA) using a weighted linear combination (WLC) to obtain a vulnerability map of dengue. Risk factors (criteria) were identified and assigned with membership values for vulnerability according to the available literature. Sensitivity analysis and validation of the model was conducted to improve the robustness and predictive ability of the map. Our study revealed marked differences in geographical vulnerability to dengue by location and season. Low-lying areas and those located along the southern border were consistently found to be at higher risk of dengue. The vulnerability extended to higher elevation areas including some areas in the Capital city Thimphu during the summer season. The higher risk was mostly associated with relatively high population density, agricultural and built-up landscapes and relatively good road connectivity.ConclusionsUsing MCDA, our study identified vulnerable areas in Bhutan during specific seasons when and where the transmission of dengue is most likely to occur. This study provides evidence for the National Vector-borne Disease Control programme to optimize the use of limited public health resources for surveillance and vector control, to mitigate the public health threat of dengue.

Highlights

The global incidence of dengue has increased over the last few decades from over 8.3 million reported infections in 1990 [1] to approximately 80 million dengue cases in 2015 [2]
In Bhutan, dengue incidence has been on the rise since 2004, with numerous outbreaks reported across the country
Using multicriteria decision analysis (MCDA), our study identified vulnerable areas in Bhutan during specific seasons when and where the transmission of dengue is most likely to occur

Summary

Introduction

The global incidence of dengue has increased over the last few decades from over 8.3 million reported infections in 1990 [1] to approximately 80 million dengue cases in 2015 (representing a ten-fold increase) [2]. Before 1970, only nine countries experienced severe dengue epidemics. More than 120 countries have endemic dengue virus (DENV) transmission, with severe dengue resulting in 21,000 deaths annually [4]. There are estimated 390 million dengue infections worldwide every year (95% credible interval [CrI] 284–528 million), of which 96 million (95% CrI 67–136 million) manifest clinically with varying degree of severity [5]. Dengue is the most rapidly spreading vector-borne disease globally, with a 30-fold increase in global incidence over the last 50 years. In Bhutan, dengue incidence has been on the rise since 2004, with numerous outbreaks reported across the country.

Methods

Results

Conclusion