Severe Dengue and Dengue-Malaria Coinfection: A Case Series from a Referral Hospital in Montería, Colombia.

Background/Objectives: Severe dengue and dengue-malaria coinfection represent major diagnostic and therapeutic challenges in tropical endemic settings, where overlapping clinical manifestations may delay recognition of deterioration. This study aimed to describe the clinical and epidemiological characteristics of patients with severe dengue, dengue with warning signs, and dengue-malaria coinfection treated at a referral hospital in Montería, Córdoba, Colombia. Methods: A retrospective case series was conducted by reviewing medical records of patients diagnosed with dengue between 2018 and 2023. Cases classified as dengue without warning signs were excluded. The final analysis included patients with dengue-warning signs, severe dengue, and dengue-malaria coinfection. Dengue classification followed the 2009 World Health Organization criteria, and malaria was confirmed by thick blood smear. Sociodemographic, clinical, laboratory, geographic, and outcome-related variables were collected. Descriptive analyses were performed, and selected categorical variables were compared using Fisher's exact test. Results: Fifty-three patients were included: 25 (47.17%) with severe dengue, 14 (26.42%) with dengue with warning signs, and 14 (26.42%) with dengue-malaria coinfection. Severe dengue was more frequent among females, whereas dengue with warning signs and coinfection predominated in males. Children accounted for the highest proportion of severe dengue cases, while coinfected cases were mainly distributed between childhood and adolescence. Fever was documented in all patients. Edema, elevated hematocrit, severe plasma leakage, and hemodynamic compromise were more frequent among severe dengue cases, whereas myalgia differed significantly across clinical groups. Ten deaths were recorded, six occurring in coinfected patients. Conclusions: Severe dengue and dengue-malaria coinfection are clinically complex conditions with overlapping manifestations and potentially fatal outcomes, highlighting the need for early recognition, differential diagnosis, and close monitoring.