A Large Dengue Outbreak in Taiwan, 2023: Driven by Imported Cases, Serotype Cocirculation, and Climate Variability
Issued Date
2026-03-01
Resource Type
eISSN
23288957
Scopus ID
2-s2.0-105032564555
Journal Title
Open Forum Infectious Diseases
Volume
13
Issue
3
Rights Holder(s)
SCOPUS
Bibliographic Citation
Open Forum Infectious Diseases Vol.13 No.3 (2026)
Suggested Citation
Huang J.Y., Weng S.F., Yang Z.S., Tung Y.W., Wang W.H., Assavalapsakul W., Thitithanyanont A., Chao D.Y., Lin C.Y., Chen Y.H., Wang S.F. A Large Dengue Outbreak in Taiwan, 2023: Driven by Imported Cases, Serotype Cocirculation, and Climate Variability. Open Forum Infectious Diseases Vol.13 No.3 (2026). doi:10.1093/ofid/ofag070 Retrieved from: https://repository.li.mahidol.ac.th/handle/123456789/115760
Title
A Large Dengue Outbreak in Taiwan, 2023: Driven by Imported Cases, Serotype Cocirculation, and Climate Variability
Corresponding Author(s)
Other Contributor(s)
Abstract
Background Taiwan, a region traditionally considered non-endemic for dengue, experienced an unexpected and large-scale outbreak in 2023. We investigated the multifactorial drivers of this outbreak, including cross-border viral importation, serotype cocirculation, vector ecology, and climate variability. Methods We analyzed national dengue surveillance data (2013-2023), meteorological records, and Breteau Index (BI) values, alongside molecular serotyping and whole-genome sequencing of clinical isolates. Time-lagged Poisson regression was used to identify predictors of indigenous dengue transmission in Kaohsiung and Tainan. Full-genome comparisons were conducted between 2023 strains and historical epidemic isolates. Results A total of 26 706 laboratory-confirmed cases were reported, primarily in Tainan (80.7%) and Kaohsiung (11.9%). Real-time RT-PCR identified cocirculating DENV-1 and DENV-2 strains. Phylogenetic analysis confirmed the 2023 DENV-1 and DENV-2 strains were genetically linked to contemporary strains from Southeast Asian countries. Whole-genome sequencing identified several nonsynonymous mutations in the NS2A, NS3, and NS5 regions when compared with historical outbreak isolates. Time-lagged regression showed that imported cases, precipitation, and the BI were associated with incidence in univariate models. In Kaohsiung, the best-fitting multivariable model included the BI, but temperature and precipitation were the independent predictors. In Tainan, precipitation and, at longer lags, imported cases were more influential, while the BI lost significance after adjustment. Conclusions The 2023 dengue outbreak in Taiwan was driven by a complex interplay between viral introductions, climatic conditions, and vector dynamics. The differing transmission drivers observed between cities highlight the need for region-specific vector surveillance, climate-informed early warning systems, and sustained genomic monitoring to prevent future re-emergence of dengue in this non-endemic setting.