Article in Japanese

Clinical characteristics of 105 patients with pandemic 2009 influenza A (H1N1) virus associated with pneumonia: a comparison between severe and non-severe cases

Shiho NISHIMURA, Yasuyuki OKADA, Yusuke IMANAKA

We investigated 105 patients with pneumonia caused by pandemic 2009 influenza A (H1N1) virus from September through December 2009. The age of the patients ranged from eight months to 12 years, and the average age was 6.2 years. Patients were divided into two groups; severe (n=78) versus non-severe cases (n=27) according to the Guideline for the Management of Respiratory Infectious Diseases in Children in Japan, 2007. The statistical analyses between two groups suggest that patients in the severe group showed the following characteristics: older age (more than 6 years of age), a history of asthma attack, atopic disposition (asthma, allergic rhinitis, food hypersensitivity, atopic dermatitis, and allergic conjunctivitis), elevated white blood cell counts (more than 12,000/μl), and progressive dyspnea with hypoxia within 24 hours after the initial attack of fever. These clinical characteristics are considered as the risk factors for the progression of respiratory distress in 2009 H1N1 patients with pneumonia. An early diagnosis considering the risk factors described above may be useful for the treatment of patients with 2009 H1N1 virus infection.

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Department of Pediatrics, Hiroshima City Funairi Hospital

Key words
Received	February 22, 2011
Accepted	July 25, 2011

23 (4)：401─406,2012