Rising dengue risk with increasing El Niño-Southern Oscillation amplitude and teleconnections.

Global climate variability has been linked with some of the largest dengue outbreaks, including the record-breaking 2023-2024 epidemic, but the understanding of their mechanism and evidence for their association is lacking. By incorporating reported dengue cases and climate data from 57 countries across the Americas and Asia from 1980 to 2024, we unpacked the global climate teleconnection and quantifying its impact on dengue cases. We revealed that the heterogeneity in the association between global climate variability and dengue cases across regions is affected by the strength and types of global climate teleconnections with temperature and precipitation. By controlling for the heterogeneity, 63% of the variation in dengue cases can be attributed to El Niño-Southern Oscillation fluctuations, with higher values in endemic regions. The 1982-83, 1997-98, 2015-16, and 2023-24 El Niño events were estimated to have induced an additional 0.2, 1.4, 4.1, and 9.6 million dengue cases, respectively, over regular seasonal patterns. Due to human-induced warming, El Niño events and teleconnections may cause a 39.0-81.7% increase in cumulative cases in 2020-2099. Our findings quantify the association between global climate variability and dengue epidemics and caution about the potential future risk.