Abstract: Objective　To study the infection of influenza virus in children with acute respiratory tract infection（ARTI） hospitalized in Children’s Hospital of Soochow University. Methods　The infection data of influenza virus in 7322 children with acute respiratory tract infection（ARTI） hospitalized in Department of Respiratory in Children’s Hospital of Soochow University from January 2016 to December 2019 were analyzed. Influenza virus was detected by RT-PCR，and the subtypes of A/H1N1，A/H3N2，B/Victoria and B/Yamagata were identified. Results　（1）Among the 7322 cases of hospitalized children，742 cases were positive for influenza virus（10.1%）. In 2016，2017，2018 and 2019，the positive rate of influenza virus was 10.4%，8.6%，6.0% and 15.2% respectively. （2）The positive rate of influenza virus-A（6.7%） was higher than that of influenza virus-B（3.6%）. The most common was A/H1N1（45.0%），followed by B/Victoria（26.4%），A/H3N2（19.1%），B/Yamagata（7.5%） in turn. There were 4 cases of A/H1N1+B/Yamagata mixed infection and 10 cases of A/H3N2+B/Victoria mixed infection. （3）The positive rate of influenza virus in ＞3-5-years-old group was the highest（14.3%），and the second was ＞1-3-years-old group（12.0%）. The onset age of influenza virus B［38.0（13.0，56.0） months］ was older than that of influenza A virus［16.0（7.0，38.0） months］（Z =-6.456，P＜0.001）. （4）The positive rate of influenza in winter was the highest，accounting for 54.9% of the total detection rate of influenza，followed by spring（36.0%）. From December 2017 to January 2018，there was an epidemic peak. （5）Influenza virus was prone to mixed infection（64.4%）. Haemophilus influenzae（21.2%） was the most common mixed infectious pathogen，followed by Streptococcus pneumoniae（17.5%） and Mycoplasma pneumoniae（15.0%）. （6）About 95.8% of hospitalized children had influenza complicated with pneumonia. The main symptoms were fever（86.7%） and cough（98.1%），followed by digestive tract symptoms（51.5%）. Conclusion　Influenza virus is an important pathogen of respiratory tract infection in hospitalized children in Children’s Hospital of Soochow University，among which A/H1N1 subtypes are the most common. There are some differences in prevalent influenza virus subtypes in different years，seasons，months and ages. The group of three to five years old is the most common，and the incidence rate is the highest in winter. Pneumonia is the main disease manifestation，and the main clinical manifestations are fever and cough. Influenza virus is prone to mixed infection，most patients have a good prognosis，and no death occurs.

Key words: influenza virus, respiratory tract infection, child, prevalent

摘要： 目的　探讨苏州大学附属儿童医院呼吸道感染住院患儿流感监测情况。方法　分析2016年1月至2019年12月在苏州大学附属儿童医院呼吸科7322例因急性呼吸道感染（ARTI）住院患儿流感病毒感染资料。采用RT-PCR法进行流感病毒的检测，并进行A/H1N1及A/H3N2、B/Victoria及B/Yamagata的亚型鉴定。结果　（1）7322例住院患儿中，共检出流感病毒阳性742例（10.1％），2016—2019年各年分别为10.4%、8.6%、6.0%、15.2%。（2）流感病毒-A检出阳性率（6.7%）高于流感病毒-B（3.6%），以A/H1N1亚型最常见（45.0%），其他依次为B/Victoria（26.4%）、A/H3N2（19.1%）、B/Yamagata（7.5%），有4例A/H1N1+B/Yamagata混合感染、10例A/H3N2+ B/Victoria混合感染。（3） ＞3～5岁组流感病毒阳性率最高（14.3%），其次是＞1～3岁组（12.0%），流感病毒-B发病年龄［38.0（13.0，56.0）个月］大于流感病毒-A［16.0（7.0，38.0）个月］（Z＝-6.456，P＜0.001）。（4）以冬季阳性检出率最高，占流感总检出率的54.9%，其次是春季（36.0%），2017年12月至2018年2月有一流行高峰。（5）流感病毒易发生混合感染（64.4％），最常见的混合感染病原是流感嗜血杆菌（21.2%），其次是肺炎链球菌（17.5%）和肺炎支原体（15.0%）。（6）95.8%的住院患儿流感合并肺炎，最主要的症状是发热（86.7%）、咳嗽（98.1%），其次是消化道症状（51.5%）。结论　流感病毒是苏州大学附属儿童医院呼吸道感染住院患儿的重要病原，以A/H1N1亚型最常见，不同年份、季节、月份及年龄流行的流感病毒亚型存在一定差异。＞3～5岁年龄组最多，冬季发病率最高，以肺炎为主要疾病表现，主要临床表现是发热和咳嗽，流感病毒易发生混合感染，多数患者预后良好，均未发生死亡。

关键词: 流感病毒, 呼吸道感染, 儿童, 流行