Severe dengue–related deaths in the elderly population soared in Southern Brazil in 2024

Introduction: Dengue fever is expanding worldwide on the track of climate change. In 2024, more than 14 million cases were reported. Around 6.5 million of those were reported in Brazil alone, reaching a staggering number of around 6000 deaths. Dengue lethality in severe cases were particularly high in Rio Grande do Sul, a historically less affected state which has witnessed an increased incidence and outbreaks in the last 4 years. Design: In this report, we raised some hypotheses to explain the high lethality. Results: Rio Grande do Sul has the highest proportion of elderly individuals among all states in Brazil. This factor, associated with the immunologically naive population, low levels of awareness to detect and treat severe dengue, and the difficulties in managing elderly patients, may have contributed to this higher lethality in severe dengue. Conclusions: The expected increasing dengue incidence in the region in the subsequent years highlights the urgent need of an integrated approach to raise awareness, reduce mosquito populations, and reduce dengue burden in the region, particularly, in the most vulnerable elderly population.