Analysis of Influenza Epidemic in Taiwan during 2015/16 Influenza Season

DOI: 10.6525/TEB.20170919.33(18).001

Ya-Tzu Chang, Yu-Ju Lin, Yi-Chien Chih, Shu-Mei Chou, Chang-Hsun Chen

2017 Vol.33 NO.18

Correspondence Author: Ya-Tzu Chang

  • Division of Preparedness and Emerging Infectious Disease, Centers for Disease Control, Ministry of Health and Welfare, Taiwan


Taiwan experienced a more severe and prolonged influenza epidemic in 2015–2016. In this study we used the nationwide surveillance data of Taiwan Centers for Disease Control to analyze the whole picture of the 2015/16 influence epidemic. The proportion of emergency department visits for influenza-like illness increased from Week 3 in 2016, peaked at Week 6, and the level exceeded the epidemic threshold for 12 consecutive weeks. As the epidemic duration prolonged, the number of cases increased dramatically. As of June 30, 2016, a total of 2,018 confirmed severe complicated influenza cases, including 425 deaths, were recorded. Nighty-five percent of them did not receive the 2015–16 influenza vaccines, 70.5% with chronic diseases, and the majority of them were infected with the influenza A(H1N1)pdm09 virus. As a result, the incidences for all age groups were the highest among the last three seasons, especially a dramatic rise among those who aged 50–64 years. To decrease the susceptible population, we purchased double amount of influenza vaccines to expand the target groups for vaccination in 2016–2017, in order to increase the coverage rates to 25% of whole populations.

Keywords:Influenza, Influenza vaccine, The proportion of emergency room visits for influenza-like illness