Age redistribution and altered RSV seasonality in Taiwan: A multicenter analysis from 2015 to 2023
Journal
International Journal of Infectious Diseases
Journal Volume
162
Start Page
108181
ISSN
1201-9712
Date Issued
2026-01
Author(s)
Chang, Tu-Hsuan
Hu, Ya-Li
Chen, Wan-Chen
Ho, Shu-Yuan
Lee, Tai-Fen
Huang, Yu-Tsung
Tang, Hung-Jen
Chang, Luan-Yin
Abstract
Objectives: Respiratory syncytial virus (RSV) is a major cause of pediatric pneumonia. In this study, we assessed RSV epidemiology in Taiwan and explored potential changes in respiratory pathogen dynamics.
Methods: We analyzed respiratory pathogen data from medical centers in Taiwan between 2015 and 2023. We also examined Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis cases to assess potential shifts in respiratory bacterial trends and age distributions. Results: A total of 7,098 RSV cases were identified. Before 2020, RSV circulated year-round, peaking from July to September. After 2020, RSV activity shifted to a sharply increased epidemic from September to December and became more synchronized nationwide. The percentage of infants (<1 year old) diagnosed with RSV decreased significantly from 56.5% to 24.1% after the pandemic (P < 0.001), whereas the percentage of children aged >2 years diagnosed with RSV increased significantly (P < 0.001). Concomitant increases in bacterial detection were observed among older children, particularly for S. pneumoniae and H. influenzae, suggesting possible viral-bacterial interactions. Conclusion: The shift in age distribution and increased bacterial codetections highlight the need for ongoing RSV surveillance. Given the unpredictability of RSV seasonality, both maternal immunization and monoclonal antibody administration may offer reliable protection for infants.
Methods: We analyzed respiratory pathogen data from medical centers in Taiwan between 2015 and 2023. We also examined Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis cases to assess potential shifts in respiratory bacterial trends and age distributions. Results: A total of 7,098 RSV cases were identified. Before 2020, RSV circulated year-round, peaking from July to September. After 2020, RSV activity shifted to a sharply increased epidemic from September to December and became more synchronized nationwide. The percentage of infants (<1 year old) diagnosed with RSV decreased significantly from 56.5% to 24.1% after the pandemic (P < 0.001), whereas the percentage of children aged >2 years diagnosed with RSV increased significantly (P < 0.001). Concomitant increases in bacterial detection were observed among older children, particularly for S. pneumoniae and H. influenzae, suggesting possible viral-bacterial interactions. Conclusion: The shift in age distribution and increased bacterial codetections highlight the need for ongoing RSV surveillance. Given the unpredictability of RSV seasonality, both maternal immunization and monoclonal antibody administration may offer reliable protection for infants.
Subjects
Haemophilus influenzae
Moraxella catarrhalis
Respiratory syncytial virus
Seasonality
Streptococcus pneumoniae
Taiwan
Publisher
Elsevier BV
Type
journal article