title: [Clinical characteristics of hospitalized cases of severe acute respiratory infection with laboratory-confirmed influenza and the risk factors analysis of influenza infection for children under 15 years old in ten provinces in China during 2009-2014].
abstract: OBJECTIVE
  To identify clinical characteristics of hospitalized laboratory-confirmed influenza cases of children under 15 years old, and their risk factors of influenza infection.
  
  
  METHODS
  Analyzing the reports of hospitalized laboratory-confirmed influenza cases of children under 15 years old who were detected by the sentinel surveillance systems in 10 provinces from December 2009 to June 2014. Such data as their demographic, medical history, clinical symptoms and signs, treatment and outcome were collected using questionnaires, with their clinical characteristics and their risk factors of influenza infection described.
  
  
  RESULTS
  Of the 2 937 severe acute respiratory infection inpatients, 190 (6.5%) were laboratory-confirmed influenza cases. 123 (64.7%) of such confirmed cases were male, and 139 (73.2%) were children under 5 years old, with age median of 3.0 years (IQR: 1.0-5.0 years). 20 (10.5%) of them had at least one chronic medical condition, mostly chronic cardiovascular disease (3.2%), immunosuppressive disease (3.2%), and cancer/tumor (2.6%). Most common clinical symptoms of the cases were fever (92.6%) and cough (88.8%), of which abnormal pulmonary auscultation (51.1%) and abnormal chest X-ray performance (36.1%) were the most common clinical signs. 29 cases (15.8%) had complications, of which pneumonia (15.3%) was most common. 16 cases (8.6%) used antiviral drugs, and 4 cases (2.2%) were admitted into ICU. Risk factor analysis suggested that age < 6 months (OR = 0.406, 95% CI: 0.203-0.815) was a protective factor against influenza infection; and age 5-9 years old (OR = 2.535, 95% CI: 1.059-6.066) was a risk factor for influenza infection.
  
  
  CONCLUSIONS
  Hospitalized laboratory-confirmed influenza cases were found mostly in children under 5 years old. Risk exposure for influenza infection varied among age groups.
authors.affiliation: Division of Infectious Disease, Chinese Center for Disease Control and Prevention (CDC), Beijing 102206, China.
authors.forename: Zhibin
authors.initials: Z
authors.lastname: Peng
authors.affiliation: Heilongjiang Provincial CDC.
authors.forename: Jun
authors.initials: J
authors.lastname: Xu
authors.affiliation: Zhejiang Provincial CDC.
authors.forename: Zhao
authors.initials: Z
authors.lastname: Yu
authors.affiliation: Hunan Provincial CDC.
authors.forename: Qianlai
authors.initials: Q
authors.lastname: Sun
authors.affiliation: Jinan Center Hospital.
authors.forename: Lusheng
authors.initials: L
authors.lastname: Li
authors.affiliation: Beijing CDC.
authors.forename: Peng
authors.initials: P
authors.lastname: Yang
authors.affiliation: Gansu Provincial CDC.
authors.forename: Zhongyi
authors.initials: Z
authors.lastname: Jiang
authors.affiliation: Guangdong Provincial CDC.
authors.forename: Min
authors.initials: M
authors.lastname: Kang
authors.affiliation: The First Affiliated Hospital of Kunming Medical University.
authors.forename: Xin
authors.initials: X
authors.lastname: Xiong
authors.affiliation: Sichuan Provincial CDC.
authors.forename: Lei
authors.initials: L
authors.lastname: Liu
authors.affiliation: Fujian Provincial CDC.
authors.forename: Yuwei
authors.initials: Y
authors.lastname: Weng
authors.affiliation: Heilongjiang Provincial People's Hospital.
authors.forename: Guozhong
authors.initials: G
authors.lastname: Zhu
authors.affiliation: The First Affiliated Hospital of Lanzhou University.
authors.forename: Linglin
authors.initials: L
authors.lastname: Liu
authors.affiliation: Huzhou First People's Hospital.
authors.forename: Xu
authors.initials: X
authors.lastname: Dong
authors.affiliation: The First Hospital of Changsha.
authors.forename: Huiqiong
authors.initials: H
authors.lastname: Pan
authors.affiliation: Peking University People's Hospital.
authors.forename: Zhaolong
authors.initials: Z
authors.lastname: Cao
authors.affiliation: Zhuhai People's Hospital.
authors.forename: Haisen
authors.initials: H
authors.lastname: Lin
authors.affiliation: The Third People's Hospital of Chengdu.
authors.forename: Hua
authors.initials: H
authors.lastname: Guo
authors.affiliation: Fujian Medical University Union Hospital.
authors.forename: Ling
authors.initials: L
authors.lastname: Li
authors.affiliation: Division of Infectious Disease, Chinese Center for Disease Control and Prevention (CDC), Beijing 102206, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Jiang
authors.affiliation: Division of Infectious Disease, Chinese Center for Disease Control and Prevention (CDC), Beijing 102206, China.
authors.forename: Jiandong
authors.initials: J
authors.lastname: Zheng
authors.affiliation: Division of Infectious Disease, Chinese Center for Disease Control and Prevention (CDC), Beijing 102206, China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Xu
authors.affiliation: Division of Infectious Disease, Chinese Center for Disease Control and Prevention (CDC), Beijing 102206, China.
authors.forename: Luzhao
authors.initials: L
authors.lastname: Feng
authors.affiliation: Division of Infectious Disease, Chinese Center for Disease Control and Prevention (CDC), Beijing 102206, China; Email: yuhj@chinacdc.cn.
authors.forename: Hongjie
authors.initials: H
authors.lastname: Yu
mesh_terms: D000208:Acute Disease; D000293:Adolescent; D000998:Antiviral Agents; D002648:Child; D002675:Child, Preschool; D002681:China / Q000453:epidemiology; D003371:Cough; D005260:Female; D005334:Fever; D006760:Hospitalization; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype; D007251:Influenza, Human / Q000453:epidemiology* / Q000473:pathology; D007297:Inpatients; D007753:Laboratories; D008297:Male; D065840:Protective Factors; D018570:Risk Assessment; D012307:Risk Factors; D018571:Sentinel Surveillance; D011795:Surveys and Questionnaires
chemical_list: D000998:Antiviral Agents