Detection of Dengue Virus and Serological Evidence of Chikungunya and Zika Virus Exposure in Patients with Acute Febrile Syndrome in Córdoba, Colombia.

Background/Objectives: Arboviral diseases transmitted by Aedes mosquitoes, including Dengue (DENV), Zika (ZIKV), and Chikungunya (CHIKV), represent a major public health challenge in tropical regions. Their clinical similarity complicates differential diagnosis, particularly in settings of viral co-circulation, and may lead to underdiagnosis. The objective was to detect acute dengue infection and assess serological evidence of Chikungunya and Zika virus exposure among patients with acute febrile syndrome and clinical suspicion of dengue in the department of Córdoba, Colombia. Methods: A prospective descriptive study was conducted between 2023 and 2024 in healthcare institutions in Montería and Sahagún. Serum samples were analyzed by ELISA to detect DENV NS1 antigen, anti-CHIKV IgM, and anti-ZIKV IgG antibodies. Sociodemographic, clinical, and laboratory variables were described, and the association between prior ZIKV infection and dengue severity was assessed. Results: Ninety patients were included. Isolated laboratory marker detection was observed for DENV NS1 antigen in 36.7% (33/90), anti-ZIKV IgG in 30.0% (27/90), and anti-CHIKV IgM in 2.2% (2/90); combined arboviral markers were identified in 22.2% (20/90), and 8.9% (8/90) had no detectable markers. Among NS1-confirmed dengue cases (n = 47), 61.7% (29/47) were classified as dengue with warning signs. Anti-ZIKV IgG detection was not associated with dengue clinical classification (p = 0.989), although platelet counts were lower in IgG-positive cases (p = 0.037). Conclusions: The findings support laboratory-supported diagnosis and integrated acute febrile illness surveillance in Córdoba, including locally adapted vector control, in a setting of arbovirus co-circulation with overlapping laboratory markers.