The burden of El Niño–Southern Oscillation-related dengue attributable to anthropogenic climate change: a multicountry modelling study

Published April 2026

Background

Dengue is known to be associated with El Niño–Southern Oscillation (ENSO) but the size of the effect is unclear, as is the influence of anthropogenic climate change (ACC). We aimed to quantify the associations between ENSO and dengue risk in 21 countries, and to estimate the contribution of ACC to the ENSO-related dengue burden.

Methods

We collected monthly dengue cases and observed and simulated climate data from 21 countries including 1237 locations from 2000 to 2019. We characterised Eastern Pacific (EP) and Central Pacific (CP) ENSO exposures for each location based on the E and C indices and their respective teleconnections. Location-specific association between ENSO exposure and dengue cases was estimated using negative binomial generalised linear model combined with best linear unbiased predictions. We also estimated the ENSO-related dengue burden under scenarios with and without ACC.

Findings

For each standard deviation increase in EP-El Niño strength and CP-La Niña strength, the overall risk of dengue cases across locations changed by 23·70% (95% CI 21·50 to 25·94) and –9·07% (–9·91 to –8·21), respectively. During 2000 to 2019, 4·45% (95% empirical CI [eCI] 3·75 to 5·32) and –3·34% (–4·01 to –2·64) of dengue cases were attributable to EP-El Niño strength and CP-La Niña strength, respectively. ACC accounted for 48·64% (95% eCI 38·01 to 60·19) of the EP-El Niño-attributable dengue increment and 33·05% (28·66 to 38·25) of the CP-La Niña-attributable reduction. These estimates corresponded to 403 197 (95% eCI 315 109 to 498 940) and –205 641 (–238 030 to –178 329) dengue cases across 1237 locations, respectively. The associations with ENSO varied strongly across the 21 countries.

Interpretation

This study presents new model-based evidence of the strong associations between ENSO and dengue risk at a multicountry level, and suggests that the contribution of ACC to the effects of ENSO might differ geographically.