Clinical and Epidemiological Features of Hospitalized Dengue Cases During the 2025 Outbreak in Mymensingh, Bangladesh

Background: Dengue fever is a significant public health challenge both globally and in Bangladesh due to the increasing disease burden and expanding geographic distribution. This study aimed to explore the clinical spectrum, disease severity distribution, and in-hospital outcomes of hospitalized adult dengue patients in Mymensingh, Bangladesh, during the 2025 outbreak, within a regional context. Methods: This study was a hospital-based prospective observational study conducted at Mymensingh Medical College Hospital (MMCH), Mymensingh, Bangladesh, from July to October 2025. About 380 adult patients admitted with confirmed dengue infection were included. Acute dengue virus infection was confirmed using laboratory criteria, defined as a positive serological test for dengue nonstructural protein 1 (NS1) antigen or dengue-specific IgM/IgG antibodies via rapid immunochromatographic assay or enzyme-linked immunosorbent assay (ELISA). Demographic data were collected through face-to-face interviews. Clinical findings on the day of admission were collected through physical examination and laboratory investigations. In-hospital outcome was also recorded. Disease severity was assessed according to the revised WHO 2009 dengue case classification. Collected data was analyzed using IBM SPSS Statistics, version 23.0 (IBM Corp., Armonk, NY, USA). Results: The mean age of the study population was 31.3 ± 11.1 (SD) years, with male predominance (315 (82.9%)). The majority of patients resided in urban areas (310 (82.1%)), and 308 (81.1%) reported a recent history of travel. Common clinical manifestations included fever and arthralgia (380 (100%) each), headache (379 (99.7%)), myalgia (357 (93.9%)), cough (250 (65.8%)), and nausea (224 (58.9%)). Warning signs were observed in 235 (62.2%) cases, while severe dengue was reported in five (1.3%). Mortality was reported in two (0.5%) cases, and four cases were referred to a higher facility. Conclusion: Young adult males constituted the majority of hospitalized dengue patients in this regional outbreak. While a high proportion presented with warning signs, hospitalization and management resulted in a low rate of progression to severe dengue and minimal mortality. These findings point towards an expanding geographical footprint of dengue beyond classical metropolitan hotspots and emphasize the critical need for decentralized healthcare preparedness, regional vector control, and mobility-linked surveillance systems across Bangladesh.