An unexpected dengue outbreak in Taiwan, 2023: A retrospective analysis of potential risk factors
Issued Date
2025-11-01
Resource Type
ISSN
18760341
eISSN
1876035X
Scopus ID
2-s2.0-105014628619
Journal Title
Journal of Infection and Public Health
Volume
18
Issue
11
Rights Holder(s)
SCOPUS
Bibliographic Citation
Journal of Infection and Public Health Vol.18 No.11 (2025)
Suggested Citation
Tung Y.W., Yang Z.S., Wang W.H., Hsu Y.T., Tsui C.I., Assavalapsakul W., Thitithanyanont A., Lin C.Y., Chao D.Y., Chen Y.H., Wang S.F. An unexpected dengue outbreak in Taiwan, 2023: A retrospective analysis of potential risk factors. Journal of Infection and Public Health Vol.18 No.11 (2025). doi:10.1016/j.jiph.2025.102939 Retrieved from: https://repository.li.mahidol.ac.th/handle/123456789/111964
Title
An unexpected dengue outbreak in Taiwan, 2023: A retrospective analysis of potential risk factors
Corresponding Author(s)
Other Contributor(s)
Abstract
Background: Taiwan experienced a major dengue outbreak in 2023 following the relaxation of COVID-19 border controls. The contributing factors remained unclear. This study investigated potential virological, immunological, and clinical drivers. Methods: We retrospectively analyzed laboratory-confirmed dengue virus (DENV) infections at a tertiary care hospital in southern Taiwan. Serotypes were identified by qRT-PCR. Viral origins were assessed through phylogenetic and envelope (E) gene amino acid analyses. Clinical features of DENV-1 and DENV-2 cases were compared. Neutralization and antibody-dependent enhancement (ADE) were evaluated using PRNT and ADE assays. Results: DENV-1 and DENV-2 were identified as the predominant circulating serotypes. Clinical analysis revealed that DENV-2 infection was significantly associated with older age, diabetes mellitus, hypertension, and elevated hematocrit levels (p < 0.05), and these associations remained statistically significant in multivariate analysis. Phylogenetic analysis showed that DENV-1 isolates belonged to genotypes I and IV, while DENV-2 strains were of the cosmopolitan genotype. These viruses clustered closely with strains from Southeast Asia. Amino acid analysis indicated that DENV-1 strains exhibited 2–10 substitutions relative to 2014 isolates, while DENV-2 strains closely matched those from 2015. Sera from the 2014–2015 outbreaks demonstrated potent homotypic but limited heterotypic neutralization. ADE was observed in heterotypic infection contexts. Conclusions: The 2023 dengue outbreak in Taiwan was driven by co-circulation of DENV-1 and DENV-2, limited heterotypic immunity, and ADE. These findings highlight the importance of integrated virological surveillance, genotype monitoring, and immunological assessment to inform dengue control strategies in non-endemic regions experiencing imported viral threats.