Laboratory-based trends in dengue and other arboviruses in the Caribbean: Analysis of surveillance data, 2018-2024

ABSTRACT Objective: To describe laboratory-based patterns of arboviral circulation, including serotype distribution and temporal trends, and their contribution to regional situational awareness in the Caribbean. Methods: This was a retrospective analysis using clinical samples submitted to the Caribbean Public Health Agency Medical Microbiology Laboratory for suspected arboviral infection. Samples were tested using Trioplex real-time reverse transcription polymerase chain reaction and immunoglobulin M and G enzyme-linked immunosorbent assays. Data were analyzed by virus type, serotype, age group, sex, and seasonality. Statistical associations were assessed using Pearson’s chi-square tests. Because the dataset is based on submitted samples, findings are presented as proportions among tested samples rather than population-level estimates. Results: Dengue virus (DENV) accounted for the largest proportion of confirmed arboviral infections (34.7%) among tested samples, with DENV-3 as the most frequently detected serotype (65.5%), followed by DENV-2 (26.8%), DENV-1 (4.3%), and DENV-4 (0.17%). Significant associations were observed between serotype and age group (χ² = 201.88; P < 0.001) and sex (χ² = 22.15; P = 0.036). Seasonal peaks were observed primarily between August and November, although an atypical increase in early 2024 was noted. Chikungunya (0.2%) and Zika (0.1%) viruses were infrequently detected. Conclusions: In this retrospective analysis, DENV was the most frequently detected arbovirus among tested samples in the Caribbean, with dynamic serotype distribution and marked seasonal variability. These findings highlight the value of laboratory-based surveillance in strengthening regional situational awareness and informing public health responses, while recognizing limitations related to representativeness and the absence of population denominators.