Global transmission suitability maps for dengue virus transmitted by Aedes aegypti from 1981 to 2019

Abstract

Mosquito-borne viruses increasingly threaten human populations due to accelerating changes in climate, human and mosquito migration, and land use practices. Over the last three decades, the global distribution of dengue has rapidly expanded, causing detrimental health and economic problems in many areas of the world. To develop effective disease control measures and plan for future epidemics, there is an urgent need to map the current and future transmission potential of dengue across both endemic and emerging areas. Expanding and applying Index P, a previously developed mosquito-borne viral suitability measure, we map the global climate-driven transmission potential of dengue virus transmitted by Aedes aegypti mosquitoes from 1981 to 2019. This database of dengue transmission suitability maps and an R package for Index P estimations are offered to the public health community as resources towards the identification of past, current and future transmission hotspots. These resources and the studies they facilitate can contribute to the planning of disease control and prevention strategies, especially in areas where surveillance is unreliable or non-existent.

Genomic epidemiology unveils the dynamics and spatial corridor behind the Yellow Fever virus outbreak in Southern Brazil

“…When looking at the years 2017–2019 for which incidence presented a clearer seasonal signal, we found a positive correlation between cases and index P of 0.47 ( P value = 0.003). As shown in previous studies, index P often precedes incidence in time due to inherent natural lags between natural climate variation and its effects on transmission ( 22 ) or due to delays in reporting. Accordingly, we found that an optimal shift of index P by +1 month into the future maximized the correlation with incidence at 0.73 ( P value = 5.7 × 10 −07 ).…”

“…We estimated transmission potential of a specific virus by a specific mosquito species ( 21 , 22 ). Because of lack of data related to mosquito species that drive YFV transmission within the animal reservoir, we were restricted to calibrating the index specifically to Aedes aegypti and have thus interpreted the suitability measure as a proxy for spillover risk into human populations rather than a measure of transmission potential overall (see Materials and Methods and Supplementary Text for full details).…”

A retrospective analysis of climate-based dengue virus transmission suitability and demographic changes over the last four decades

“…One of the major challenges of using our results to inform dengue control efforts will be to understand how favorable climate-based transmission suitability may drive future dengue transmission in specific locations and contexts. While we have previously characterized the relationship between Index P and dengue incidence across a variety of environmental conditions (26), we encourage researchers to interpret our estimates for a region of interest within the context of local demographic, economic and ecological conditions. Furthermore, our estimates of transmission suitability reflect the past and should not be interpreted as predictions for what will happen decades into the future.…”

“…Uncertainty estimates including the 50% and 90% credible intervals for these values were calculated using summary statistics from 1000 simulations of the spatiotemporal maps of Index P provided with the dataset from Nakase et al (26).…”

“…In this study we quantify spatiotemporal trends in climate-based dengue transmission suitability at a high spatial resolution over the last four decades using a widely validated mechanistic DENV suitability measure for Ae. aegypti mosquitoes referred to as Index P (19,(24)(25)(26). Index P is a proxy for the transmission potential of a single adult female mosquito under conditions where susceptible hosts, the virus and its vectors are assumed to be present.…”