A causal-based analysis on the role of seasonal climate patterns in dengue disease transmission

Vector-borne diseases transmitted by Aedes mosquitoes such as dengue, Zika, and chikungunya pose significant public health challenges worldwide in the wake of climate change. However, while their transmission is known to be susceptible to climate variables like temperature, rainfall or humidity, the overall role of large-scale climate patterns on the emergence of these diseases is not so well understood. Establishing the most important timeframes for Aedes-borne disease prediction and identifying climate patterns that drive its emergence can be key in the development of actionable, climate-based dengue prediction systems.

In this work, we explore and analyse the response of the climate-driven component of Aedes-borne disease transmission. A timescale decomposition methodology characterises the main timescales over which processes condition transmissibility, while subsequent correlation and causality analyses identify the most relevant predictors for Aedes-borne diseases in the form of climate variability patterns.

We find Aedes-borne disease transmission to be susceptible to multiple factors: Long-term climate trends have a significant impact on dengue suitability in the tropics, where El Niño Southern Oscillation and the Indian Ocean Basin amplify or dampen emergence based on the sign of their respective phases. Temperate regions are more susceptible to year-round climate variability, where multi-scale climate patterns, through teleconnections and compound interactions, can influence transmission dynamics. The results of this study highlight the multi-faceted role of climate patterns in disease emergence, as well as their potential applicability to better inform public health strategies to manage future outbreaks.