Jpn. J. Infect. Dis., 65 (3), 208-214, 2012

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Zi-feng Yang^1,3, Yang-qing Zhan², Rong-chang Chen²*, Rong Zhou³, Yu-tao Wang³, Yi Luo⁴, Mei Jiang², Ji-qiang Li⁴, Sheng Qin³, Wen-da Guan³, Ke-fang Lai², Huan-lian Wen⁵, Zeng-wei Liang⁵, Li Li², and Nan-shan Zhong²

¹Macau University of Science and Technology, Faculty of Chinese Medicine, Macau SAR; ²Department of Respiratory Medicine of The First Affiliated Hospital of Guangzhou Medical College, State Key Laboratory of Respiratory Disease (Guangzhou Medical University), Guangzhou City; ³The First Affiliated Hospital of Guangzhou Medical College, Division of Clinical Virology of State Key Laboratory of Respiratory Disease (Guangzhou Medical University), Guangzhou City; ⁴Guangdong Provincial Hospital of Traditional Chinese Medicine, Emergency Department, Guangzhou City; and ⁵Department of Infectious Disease of The First Affiliated Hospital of Guangzhou Medical College, Guangzhou City, P.R. China

(Received October 24, 2011. Accepted March 7, 2012)

*Corresponding author: Mailing address: Department of Respiratory Medicine of The First Affiliated Hospital of Guangzhou Medical College, State Key Laboratory of Respiratory Disease (Guangzhou Medical University, China), No. 151 Yanjiang Road, Guangzhou City, P.R. China 510120. Tel: +86-20-83062870, Fax: +86-20-83062729, E-mail: このメールアドレスはスパムボットから保護されています。閲覧するにはJavaScriptを有効にする必要があります。

SUMMARY: Comparisons of the clinical characteristics of contemporaneous pandemic (H1N1) 2009 influenza A virus (A(H1N1)pdm09)- and seasonal influenza viruses-infected patients are important for both clinical management and epidemiological studies. A prospective multicenter observational study was conducted using a preestablished sentinel surveillance system in Guangzhou, China during 2009. In this study, the clinical presentations of patients with either acute respiratory infection or community-acquired pneumonia were recorded, and nasopharyngeal swab samples were collected for detection of respiratory virus strains using cell cultures or real-time reverse transcription/real-time polymerase chain reaction. Comparisons of the clinical features between A(H1N1)pdm09- and seasonal influenza viruses-infected patients were conducted accordingly. Of the 1,498 patients examined, 265 tested positive for A(H1N1)pdm09, 286 were positive for seasonal influenza A viruses, and 137 for influenza B viruses. The predominant virus was influenza B before the emergence of A(H1N1)pdm09 (epidemiological week [EW] 1–EW 21); then, predominantly non-A(H1N1)pdm09 influenza A and, later, A(H1N1)pdm09, which peaked in EW 46. Compared with the common seasonal influenza-infected patients, A(H1N1)pdm09-infected patients were younger, and had a higher proportion of these patients reported prior contact with infected individuals (P < 0.001, by χ² test). However, few significant differences were observed in clinical symptoms and severity among any of the infections caused by the different influenza A strains. Our hospital-based network served as a useful source of information during A(H1N1)pdm09 monitoring. Viral distribution in Guangzhou was characterized by a sharp rise in A(H1N1)pdm09-infected patients in September 2009. Similar to seasonal influenza A-infected cases, A(H1N1)pdm09 cases had a very small proportion of severe cases.