Spatiotemporal patterns and clinical characteristics of leptospirosis hospitalizations in Ecuador: a nationwide study (2018-2023).

Leptospirosis is a neglected zoonotic disease highly sensitive to hydro-meteorological changes, posing significant challenges for health systems in endemic regions like Ecuador. The objective of this study was to analyze the spatiotemporal patterns and clinical characteristics of leptospirosis hospitalizations in Ecuador from 2018 to 2023, identifying vulnerability factors for in-hospital mortality and geographical distribution. A retrospective nationwide study was conducted using hospital discharge records (ICD-10: A270, A278, A279), calculating age-adjusted hospitalization and mortality rates per 100,000 inhabitants. Associations between sociodemographic variables, clinical forms, and vital status were assessed using Fisher's exact test and Pearson's Chi-square test. A total of 573 hospitalized cases and 11 deaths were analyzed. The results indicated that the icterohemorrhagic form (A270) was the primary determinant of mortality (p = 0.001); while it accounted for only 4.8% of survivors, it represented 45.5% of all fatal cases. Conversely, unspecified leptospirosis (A279) comprised 91.6 % of cases but showed lower lethality, and neither age nor sex were statistically significant predictors of death (p > 0.05). Temporally, hospitalization rates remained stable from 2018 to 2022, reaching a nadir of 0.0249 per 100,000 in 2021, but surged four-fold in 2023 to 0.1351 per 100,000. This outbreak was geographically concentrated in the Coastal provinces, particularly Guayas and Manabí, coinciding with reports of extreme rainfall. In conclusion, mortality in hospitalized patients is driven mainly by the clinical phenotype (A270) rather than demographic factors. The dramatic surge in 2023 highlights the region's vulnerability to environmental changes, suggesting that public health strategies must prioritize early diagnosis to differentiate severe forms and strengthen "One Health" surveillance in high-risk coastal areas to mitigate future climate-associated outbreaks.