Research Highlights

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  • Clinical medicine

Published online: 23 December 2009 | doi:10.1038/nchina.2009.242

Public health: When swine flu first hit China

Felix Cheung

Introduction

© (2009) istockphoto.com/Pablo A. Puente

On 10 May 2009, China reported its first case of swine-origin influenza A (H1N1) virus infection — which at the time had already hit Mexico, the United States and some other parts of the world. During the following two months, the country identified more cases in 20 provinces. Xingwang Li and Chen Wang at Capital Medical University in Beijing and co-workers¹ have followed 426 confirmed cases in 61 hospitals and learnt important clinical features of the 'swine flu' virus infection.

The researchers used a highly sensitive diagnostic tool, known as reverse transcriptase polymerase chain reaction (RT-PCR) analysis, to confirm swine flu cases. They closely monitored all cases during diagnosis, documenting the nature and symptoms of the infection.

The researchers found that the average incubation period of swine flu virus infection is two days; the two most common symptoms are fever and cough; the incidence of diarrhoea is 2.8%; and the incidence of nausea and vomiting is 1.9%. In other words, people who have swine flu virus infection usually suffer mild illness.

The researchers also found that it typically took six days to confirm cases of infection by RT-PCR diagnosis, and that patients who receive the antiviral drug oseltamivir (or Tamiflu^®) take less time to recover than those who have no treatment.

The authors of this work are from:
Beijing Chaoyang Hospital, Beijing Institute of Respiratory Medicine, Capital Medical University, Beijing, China; Beijing Ditan Hospital, Institute of Infectious Diseases, Capital Medical University, Beijing, China; Eighth People's Hospital, Guangzhou, China; Shanghai Public Health Clinical Center, Shanghai, China; Fujian Provincial People's Hospital, Fuzhou, China; West China Medical School, West China Hospital, Sichuan University, Chengdu, China; Chinese National Influenza Center, Chinese Center for Disease Control and Prevention, Beijing, China.

Reference

1. Cao, B. et al. Clinical features of the initial cases of 2009 pandemic influenza A (H1N1) virus infection in China. N. Engl. J. Med. doi:10.1056/NEJMoa0906612 (2009). | Article | OpenURL