Dengue's Clinical Course in One of Colombia's Most Endemic Areas: Impact of Endemic and Epidemic Periods.

Dengue is a viral disease with a broad spectrum of clinical manifestations. Its severity is associated with risk factors such as periods of endemicity, although the extent of this contribution is unclear. In the present study, the characteristics of the clinical course and differences in the occurrence of severe and lethal outcomes were assessed by the degree of endemicity in patients with dengue treated in health institutions in Cali, Colombia, between 2019 and 2022. A longitudinal, observational-historical, single-cohort study was conducted. Analysis involved evaluating clinical complications during epidemic and endemic periods. Mortality, cumulative incidence of hospital or intensive care unit (ICU) admission, and survival time were estimated using the competing risks method. A total of 1,038 dengue cases were included. Patients with severe dengue and those with warning signs (WS) were consulted up to 6 or 5 days after symptom onset, respectively. A hospital stay of 2.0 days (Quartile [Q]1-Q3: 2-4 days) and an ICU stay of 4.5 days (SD ± 3.9 days) were estimated. A mortality rate of 5.5% was obtained for severe dengue, and a mortality rate of 0.4% was identified for patients with WS. In 2020 and 2021, the probability of hospitalization was 20% from initial contact. The likelihood of dying within 10 days after initial contact was 0% in 2019 and 11.2% (95% CI: 4.0-22.5%) in 2020. The incidence of hospitalization, number of hospital days, and ICU stays due to dengue varied by epidemiological year in a high-endemicity area. The probability of severe and lethal clinical outcomes was higher during 2020 and 2021.