Economic impact of dengue in Singapore from 2010 to 2020 and the cost-effectiveness of Wolbachia interventions.

Stacy Soh,Annabel Seah,Kelvin Bryan Tan,Lee Ching Ng,Soon Hoe Ho,Jue Tao Lim,Shuzhen Sim,Alex R Cook,Janet Ong,Joel Ruihan Koo,Borame Sue Dickens,Ken Wei Tan,Yubraj Acharya

doi:10.1371/journal.pgph.0000024

Abstract

The release of Wolbachia-infected mosquitoes is a promising disease intervention strategy that aims to control dengue and other arboviral infections. While early field trials and modelling studies suggest promising epidemiological and entomological outcomes, the overall cost effectiveness of the technology is not well studied in a resource rich setting nor under the suppression approach that aims to suppress the wild-type mosquito population through the release of Wolbachia-infected males. We used economical and epidemiological data from 2010 to 2020 to first ascertain the economic and health costs of dengue in Singapore, a high income nation where dengue is hyper-endemic. The hypothetical cost effectiveness of a national Wolbachia suppression program was then evaluated historically from 2010 to 2020. We estimated that the average economic impact of dengue in Singapore from 2010 to 2020 in constant 2010US$ ranged from $1.014 to $2.265 Billion. Using empirically derived disability weights, we estimated a disease burden of 7,645-21,262 DALYs from 2010-2020. Under an assumed steady-state running cost of a national Wolbachia suppression program in Singapore, we conservatively estimate that Wolbachia would cost an estimated $50,453-$100,907 per DALYs averted and would lead to an estimated $329.40 Million saved in economic costs over 2010 to 2020 under 40% intervention efficacy. Wolbachia releases in Singapore are expected to be highly cost-effective and its rollout must be prioritised to reduce the onward spread of dengue.

Highlights

Increasing urbanization, human population density and climate change has led to an expanded geographical coverage of the primary vector of dengue, Ae. aegypti, and has resulted in an estimated annual 105 million dengue infections globally [1]
Using the more conservative friction cost method with constant symptomatic rates, we estimated that the total economic cost of dengue across 2010 to 2020 was 2010US$1.014 Billion (Bn) (Fig 2, 95% uncertainty interval (UI): $0.796 –$ 1.276)
The human capital method resulted in significantly higher costs, with the total economic cost estimated to be at 2010US$1.401 Billion (Bn) (Fig 2, 95% UI: $1.182 –$1.628) and 2010US$3.003 Billion under the constant and age-dependent symptomatic rates respectively, driven primarily by the increased costs of deaths under this method

Summary

Introduction

Increasing urbanization, human population density and climate change has led to an expanded geographical coverage of the primary vector of dengue, Ae. aegypti, and has resulted in an estimated annual 105 million dengue infections globally [1]. The burden of dengue is high, in the tropics and subtropics where vector breeding conditions are favourable and transmission persists year-round [2,3,4,5]. Economic impact of dengue and the cost-effectiveness of Wolbachia interventions

Methods

Results

Discussion

Conclusion