Department of Pediatrics, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Japan.
Pediatr Allergy Immunol. 2011 Feb;22(1 Pt 2):e119-23. doi: 10.1111/j.1399-3038.2010.01090.x.
The number of human cases of pandemic H1N1 influenza viral infection has increased in Japan since April 2009, as it has worldwide. This virus is widespread in the Yamaguchi prefecture in western Japan, where most infected children exhibited respiratory symptoms. Bronchial asthma is thought to be one of the risk factors that exacerbate respiratory symptoms of pandemic H1N1-infected patients, but the pathogenesis remains unclear. We retrospectively investigated the records of 33 children with pandemic H1N1 influenza viral infection who were admitted to our hospital between October and December 2009 and analyzed their clinical features. The percentage of children with asthma attack, with or without abnormal findings on chest radiographs (pneumonia, atelectasis, etc.), caused by pandemic H1N1 influenza infection was significantly higher than that of children with asthma attack and 2008-2009 seasonal influenza infection. Of the 33 children in our study, 22 (66.7%) experienced an asthma attack. Among these children, 20 (90.9%) did not receive long-term management for bronchial asthma, whereas 7 (31.8%) were not diagnosed with bronchial asthma and had experienced their first asthma attack. However, the severity of the attack did not correlate with the severity of the pulmonary complications of pandemic H1N1 influenza viral infection. The pandemic H1N1 influenza virus greatly increases the risk of lower respiratory tract complications such as asthma attack, pneumonia, and atelectasis, when compared to the seasonal influenza virus. Furthermore, our results suggest that pandemic H1N1 influenza viral infection can easily induce a severe asthma attack, pneumonia, and atelectasis in atopic children without any history of either an asthma attack or asthma treatment.
自 2009 年 4 月以来，日本的甲型 H1N1 流感病毒感染人数不断增加，全球范围内亦是如此。这种病毒在日本西部的山口县广泛传播，大多数受感染的儿童表现出呼吸道症状。支气管哮喘被认为是使甲型 H1N1 感染患者呼吸道症状恶化的危险因素之一，但发病机制尚不清楚。我们回顾性调查了 2009 年 10 月至 12 月期间我院收治的 33 例甲型 H1N1 流感病毒感染患儿的记录，并分析了他们的临床特征。甲型 H1N1 流感感染引起的哮喘发作患儿的比例（伴或不伴有胸部 X 线异常，如肺炎、肺不张等），明显高于哮喘发作患儿和 2008-2009 年季节性流感感染患儿。在我们的研究中，33 例患儿中有 22 例（66.7%）发生了哮喘发作。在这些患儿中，20 例（90.9%）未接受支气管哮喘的长期管理，而 7 例（31.8%）未被诊断为支气管哮喘，且首次发作哮喘。然而，哮喘发作的严重程度与甲型 H1N1 流感病毒感染的肺部并发症的严重程度无关。与季节性流感病毒相比，甲型 H1N1 流感病毒大大增加了哮喘发作、肺炎和肺不张等下呼吸道并发症的风险。此外，我们的结果表明，甲型 H1N1 流感病毒感染可使无哮喘发作或哮喘治疗史的特应性儿童易发生严重哮喘发作、肺炎和肺不张。
