Early warning of serotype replacement, spatial risk redistribution, and shifting clinical phenotypes: Insights from...

Dengue remains a major public health challenge in hyperendemic regions, where shifts in serotype circulation, spatial transmission patterns, and clinical presentation can significantly influence outbreak dynamics. Colombia has experienced intense dengue activity in recent years; however, integrated analyses combining virological, spatial, and clinical data remain limited.

A retrospective longitudinal observational study was conducted using routinely collected dengue surveillance data from the Department of Meta, Colombia, covering the period from January 2023 to September 2025. Confirmed dengue cases with viral isolation and serotype identification were included. Temporal trends, serotype replacement dynamics, municipal-level spatial redistribution patterns, and clinical characteristics were analyzed using laboratory-confirmed dengue cases. Multivariable logistic regression models were used to identify factors associated with dengue positivity overall and by serotype, while interannual variation was assessed to evaluate changes in transmission intensity and the spatial redistribution of dengue transmission risk.

Marked serotype replacement was observed during the study period. DENV-2 predominated during the 2023 peak, followed by a decline and a sustained increase in DENV-3 and DENV-4 by 2025, while DENV-1 disappeared from recent records. Spatial analysis showed declining diagnostic positivity in historically hyperendemic municipalities and significant interannual increases in intermediate municipalities, indicating an epidemiological rebound outside major urban centers. Classical dengue symptoms, including headache, myalgia, and rash, were inversely associated with virological confirmation, whereas nonspecific neurological manifestations, such as somnolence and irritability, emerged as independent predictors. Severe thrombocytopenia remained strongly associated with infection, particularly in DENV-2 cases.

The dengue outbreak in Meta (2023-2025) was characterized by dynamic serotype replacement, spatial redistribution of transmission risk, and changing clinical presentations. The rapid emergence of DENV-4 in 2025 serves as an early warning of serotype replacement and underscores the need to update clinical screening protocols to include nonspecific neurological manifestations. Strengthening decentralized laboratory networks and closing surveillance gaps in low-endemicity areas are strategic priorities to improve early detection and outbreak control in hyperendemic regions.