title: [Risk factors for acute respiratory syncytial virus infection of lower respiratory tract in hospitalized infants].
abstract: OBJECTIVE
  To investigate the clinical epidemiologic characteristics and analyze risk factors for acute respiratory syncytial virus (RSV) infection in hospitalized infants with acute lower respiratory tract infection (ALRI).
  
  
  METHODS
  ALRI infants admitted to Children's Hospital of Fudan University from March 1st, 2011 to February 29th, 2012, were enrolled in this study. Patient information included demographic characteristics, feeding history, family status, clinical presentation, accessory examination, treatment and prognosis. According to the etiology of ALRI infants, we compared the seasonal distribution, demographic characteristics, household characteristics and underlying diseases between RSV-positive patients and RSV-negative patients. Univariate and multiple Logistic regression analyses were used to determine factors that were associated with risk of RSV infection.
  
  
  RESULTS
  Among 1 726 ALRI infants, there were 913 RSV-positive infants (52.9%). The occurrence of RSV infection had a seasonal variation, with a peak in winter (59.1%). The median (P25, P75) age of RSV infants was 64 (21-155) days. The gestational age (GA) and body weight (BW) was (37.5 ± 2.4) weeks and (3.07 ± 0.66) kg, respectively. The male/female ratio among these was 1.9: 1. RSV infection was more popular among infants in the families with smoking members, crowded living conditions, history of atopic mother. Differences of the proportion of patients with underlying disease between RSV-positive and negative groups were statistically significant (59.4% vs. 54.2%, P < 0.05). Univariate logistic regression demonstrated that factors increasing the risk of RSV infection were: GA<37 weeks (OR = 1.346, 95%CI: 1.037-1.748), birth weight <2 500 g (OR = 1.447, 95%CI: 1.103-1.898), underlying diseases (OR = 1.232, 95%CI: 1.018-1.492), underlying CHD (OR = 1.391, 95%CI: 1.120-1.728), environmental tobacco smoke exposure (OR = 1.254, 95%CI: 1.035-1.519), mother with atopic diseases (OR = 1.827, 95%CI: 1.296-2.573), crowded house with four or more than four family members (OR = 1.232, 95%CI: 1.013-1.498), autumn or winter infection (OR = 1.351, 95%CI: 1.024-1.783; OR = 1.713, 95%CI: 1.332-2.204). Multivariate logistic regression determined the factors increasing the risk of RSV infection were: underlying CHD (OR = 1.298, 95%CI: 1.002-1.681), mother with atopic diseases (OR = 1.766, 95%CI: 1.237-2.520), autumn or winter infection (OR = 1.481, 95%CI: 1.105-1.985; OR = 1.766, 95%CI: 1.358-2.296).
  
  
  CONCLUSIONS
  The prevalence of RSV infection was the highest in winter, while preterm and low birth weight infants were more susceptible. Underlying diseases were found in 59.4% cases, CHD was the most common one. The factors increasing the risk of RSV infection were: CHD, mother with atopic diseases, autumn or winter infections.
authors: Department of Pneumology, Children's Hospital of Fudan University, Shanghai 201102, China.
authors: Xiaobo
authors: X
authors: Zhang
authors: Department of Pneumology, Children's Hospital of Fudan University, Shanghai 201102, China.
authors: Lijuan
authors: L
authors: Liu
authors: Department of Pneumology, Children's Hospital of Fudan University, Shanghai 201102, China.
authors: Peng
authors: P
authors: Shi
authors: Department of Pneumology, Children's Hospital of Fudan University, Shanghai 201102, China.
authors: Gaoli
authors: G
authors: Jiang
authors: Department of Pneumology, Children's Hospital of Fudan University, Shanghai 201102, China.
authors: Pin
authors: P
authors: Jia
authors: Department of Pneumology, Children's Hospital of Fudan University, Shanghai 201102, China.
authors: Chuankai
authors: C
authors: Wang
authors: Department of Pneumology, Children's Hospital of Fudan University, Shanghai 201102, China.
authors: Libo
authors: L
authors: Wang
authors: Department of Pneumology, Children's Hospital of Fudan University, Shanghai 201102, China. Email: llqian@126.com.
authors: Liling
authors: L
authors: Qian
mesh_terms: D000208:Acute Disease; D002681:China / Q000453:epidemiology; D004781:Environmental Exposure / Q000009:adverse effects*; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D016015:Logistic Models; D008297:Male; D015995:Prevalence; D018357:Respiratory Syncytial Virus Infections / Q000453:epidemiology* / Q000517:prevention & control; D018113:Respiratory Syncytial Virus, Human / Q000302:isolation & purification*; D012141:Respiratory Tract Infections / Q000453:epidemiology* / Q000517:prevention & control / Q000821:virology; D012189:Retrospective Studies; D012307:Risk Factors; D012621:Seasons; D012959:Socioeconomic Factors; D014028:Tobacco Smoke Pollution
chemical_list: D014028:Tobacco Smoke Pollution