Climate extremes, average conditions and temperature variability as drivers of dengue epidemics in a temperate city of Argentina

Abstract

Introduction. Climate change represents one of the greatest health threats of our time, which include the expansion of mosquito-borne viruses globally. Argentina has experienced long-term changes in precipitation and temperature, enhancing the climatic suitability for dengue transmission. This study assesses climate extremes, average climate conditions, and temperature variability concerning the epidemics in a city with temperate climate in central Argentina. Methods. A set of descriptive indices for temperature and precipitation extremes was analyzed to detect long-term changes and variability in climate extremes from 1940 to 2022, as well as temperature variability during the major epidemics of 2020 and 2023. To evaluate the influence of the climate on epidemics, time series of cases and climatic variables were analyzed, generalized linear models were applied, and a mathematical model was used to estimate the number of days required for the transmission of the dengue virus.Results. All analyzed components of the climate have influenced the evolution of dengue in the studied city. Climate extremes may have increased the frequency and magnitude of epidemics. Average temperature and precipitation have shape the seasonality and temporality (onset, development, and end) of epidemics. Temperature variability has impacted the extrinsic incubation period, thereby defining the magnitude and duration of epidemics. Conclusion. The trend towards warmer conditions and increased intense precipitation events may drive more frequent and higher-incidence epidemics, given the specific average climate and climate variability of the studied city. We emphasize the necessity for enhancing monitoring systems, encompassing epidemiological, climatic, and vector variables, to mitigate the impacts of future epidemics.