Factors associated with death in severe dengue: a retrospective cohort study in Espírito Santo, Brazil, 2020-2024Factors associated with death in severe dengue: a case-control study in Espírito Santo, Brazil, 2020-2024.

OBJECTIVE: To identify factors associated with death among patients with severe dengue. METHODS: We conducted a population-based retrospective cohort study including all laboratory-confirmed severe dengue cases reported in Espírito Santo, Brazil, between 2020 and 2024. Participants were classified according to the recorded outcome as fatal or non-fatal severe dengue cases. RESULTS: Among 251 laboratory-confirmed severe dengue cases, 117 (46.6%) resulted in death. Fatal cases were significantly older than survivors. In the overall multivariable model, weak or undetectable pulse (RR 1.74; 95% CI 1.34-2.26), late-stage arterial hypotension (RR 1.80; 95% CI 1.34-2.42), progressive increase in hematocrit (RR 1.43; 95% CI 1.10-1.85), and altered level of consciousness (RR 1.31; 95% CI 1.02-1.67) were associated with a higher risk of death. Conversely, fever (RR 0.72; 95% CI 0.56-0.92) and a sudden drop in platelet count (RR 0.76; 95% CI 0.59-0.91) were associated with a lower risk of death. In the exploratory age-stratified analyses, weak or undetectable pulse and late-stage arterial hypotension remained associated with a higher risk of death in both age groups, while progressive increase in hematocrit and sudden platelet drop were associated with death only among individuals aged <60 years, and fever was associated with a lower risk of death only among those aged ≥60 years. CONCLUSION: Mortality in severe dengue is predominantly associated with markers of advanced hemodynamic instability rather than early warning signs, particularly among older adults.