Dengue serotype dynamics in northeastern Peru: A study from the Amazonas region, 2021–2025

A significantly heterogeneous distribution of DENV serotypes was observed across provinces (p < 0.001). DENV-2 was the most prevalent serotype and was predominantly associated with large-scale outbreaks. DENV-1 and DENV-3 circulated less frequently. No significant association was found between serotype and clinical classification or overall incidence. However, prior dengue infection (based on clinical-epidemiological records that included self-report) was significantly associated with a reduced likelihood of developing warning signs (p = 0.032) CONCLUSIONS: Between 2021 and 2025, the Amazonas region exhibited a spatiotemporally varied pattern of DENV serotype circulation, with DENV-2 as the dominant serotype linked to major outbreaks. While serotypes were not directly associated with clinical severity, previous infection (based on clinical-epidemiological records that included self-report) conferred partial protection against severe manifestations. These findings underscore the importance of continuous serotype surveillance to inform public health interventions.