Dengue incidence and its relationship with El Niño oceanic index, as a sensitive variable to anticipate outbreaks in the Colombian Caribbean region

Introduction: The Lancet Countdown 2023 report for Latin America indicates that rising temperatures influence the transmission of the dengue virus. In Colombia’s Caribbean region, a significant association has been identified between dengue incidence and climatic variables, such as temperature, humidity, and precipitation. Objective: To analyze the relationship between the incidence of dengue and the oceanic Niño index in the departments of the Colombian Caribbean region from 2021 to 2023. Materials and methods: An ecological time series study was conducted using distributed lag non-linear models and autoregressive integrated moving average models in the seven departments of the Caribbean region. Descriptive and autoregressive analyses were performed using JASP and RStudio. Non-linear and lagged analyses were run with the dlnmpackage in RStudio. Results: A positive and significant relationship between the oceanic Niño index and dengue incidence was found for 2023 data, the year when the El Niño - ENSO (El Niño-Southern Oscillation) warm phase occurred. Bolívar, Cesar, Córdoba, and Magdalena departments showed positive correlations. A non-linear relationship between El Niño/La Niña and dengue incidence was also observed, with a higher increase in dengue cases during El Niño events. Conclusions: The oceanic Niño index appears to be a useful climatic indicator for monitoring increases in the monthly dengue incidence rate in the analyzed departments of Colombia’s Caribbean región.