-
Spatiotemporal trends in severe complicated influenza among the local population in Taiwan region, 2003-2023
-
Kangjun Wu, Yujian Lu
-
Epidemiol Health. 2025;47:e2025016. Published online April 2, 2025
-
DOI: https://doi.org/10.4178/epih.e2025016
-
-
 Abstract
Summary
 PDF Supplementary Material
-
Abstract
OBJECTIVES
Severe influenza has raised considerable concern worldwide, and its incidence appears to have shifted in the context of globalization. This study aimed to examine the temporal, spatial, and demographic distributions of local severe influenza cases in Taiwan region from January 2003 to June 2023.
METHODS We aggregated severe complicated influenza cases by month, area (city/county), age, and sex. The age-standardized incidence rate (ASIR) was calculated to compare differences across regions and populations. Yearly incidence rate ratios comparing males to females were also computed to assess sex differences.
RESULTS A total of 16,459 cases were included from 2003 to 2023. Crude incidence rates per 100,000 population were 0.07-0.14 for 2003-2008, 3.64-9.81 for 2009-2019, and 0.00-1.87 for 2020-2023. Higher incidence rates were observed in Hualien and Taitung Counties, with average ASIRs exceeding 10.00 per 100,000 population, compared to other cities. Except for 2005 and 2007, the incidence among males exceeded that among females, with ASIR ratios ranging from 1.10 to 2.20. The highest incidence was observed among populations aged 0-4 and those aged ≥55.
CONCLUSIONS The incidence of severe complicated influenza exhibited clear regional and demographic variations in Taiwan region. The observed rebound in incidence calls for increased vigilance to protect vulnerable populations from severe illness.
-
Summary
Key Message
In Taiwan Region, the incidence rate of severe complicated influenza was significantly higher between 2009 and 2019 compared to the periods both preceding and following this decade, with a notable resurgence trend emerging in 2023. Severe complicated influenza cases exhibited distinct spatial clustering patterns, particularly concentrated in Taichung and Hualien. Males faced elevated morbidity risks, while both young children and the elderly showed heightened vulnerability—though the elderly population drove the majority of cases.
|
KSE
