Analysis of pdm-H1N1 Severe Complicated Influenza Cases in Eastern Region of Taiwan, 2008-2011

Ming-Ching Liu1, Jiunn-Shyan Julian Wu1, Ching-Fen Ko1,Hsiang-Ming Hsu2, Jhao-Long Chen3, Yeong-Sheng Lee4

2012 Vol.28 NO.4

Correspondence Author： Ming-Ching Liu

Abstract：

To understand the evolving features of the pandemic H1N1 (pdm-H1N1) severe complicated influenza cases (SCICs) in Eastern Region of Taiwan, we retrospectively reviewed those confirmed cases between April 2008 and March 2011, and categorized their date of onset into three periods, which were pre-, during, and post- pdm-H1N1 Influenza epidemic period (IEP) for April 2008 through March 2009, April 2009 through March 2010, and April 2010 through March 2011, correspondingly. In the pre-pdm-H1N1 IEP, there was only one SCIC. After the global outbreak of pdm-H1N1 influenza, the number of SCIC increased sharply to 104 and 195, and among them, 99 (95.2%) and 89 (45.6%) were seropositive for pdm-H1N1 influenza during and post pdm-H1N1 IEP, respectively. During both periods, there were six fatal SCICs (i.e. a mortality rate of 10.5/106), which were 4.8 and 1.9 times, respectively, of the national rate in Taiwan. Among the 188 pdm-H1N1 SCICs confirmed during and post pdm-H1N1 IEP, all of them were hospitalized and 43 (22.9%) had underlying diseases. Among them, 27 were cared in intensive care units (ICUs) and the rest 161 cases admitted into general wards. These two hospitalized groups showed differential symptoms - 24 (88.9%), 21 (77.7%) and 18 (66.7%) cases hospitalized in ICUs showed pneumonia in X-ray, fever and difficulty breathing; and 147 (91.3%), 132 (82.0%), and 123 (76.4%) cases hospitalized in general wards showed fever, pneumonia in X-ray, and coughing, respectively. Death occurred in 11 pdm-H1N1 SCICs, of which eight were Hualien residents and three were Taitung residents, with a mean age of 54.7 (37 to 72) and 25.3 (22 to 30), respectively. Risk factors for SCIC mortality were underlying diseases in both counties. In addition to underlying diseases, SCIC deaths in Taitung County had additional risk factors of obesity and pregnancy, with body mass index between 34.7 and 50.7.