title: [Viral etiology of pneumonia in children].
abstract: To evaluate the viral pathogen of pneumonia in children.
  
  
  
  A total of 13 642 cases of children pneumonia in 3 years were enrolled in this study. Antigens of viral pathogen in respiratory excretion, including respiratory syncytial virus (RSV), type 1, 2 and 3 parainfluenza virus, type A and B influenza virus, and adenovirus were detected by direct immunofluorescence method.
  
  
  
  Viral pneumonia accounted for 34.3% of all cases, including 25.8% cases of RSV, 4.7% of parainfluenza virus, 2.4% of type A influenza virus, 0.2% of type B influenza virus and 1.3% of adenovirus. Coinfection was found in 20 cases, in which 17 cases (85%) were infected with RSV and another virus. Positive rates of RSV in children < or = 1 year, 1 to 3 years, and >3 years were 33.1%, 19.7% and 5.1% with a significant difference (chi(2)(trend)=763.4, P < 0.001). The positive rate of adenovirus in children < or =1 year (0.7%) was significantly lower than that in children aged 1 to 3 years and in children >3 years (2.3% and 2.5%) (all P<0.01). The positive rate of type A influenza virus in children aged 1 to 3 years was higher than that in children < or =1 year (chi(2)=18.2, P<0.01). Type 1 parainfluenza virus was found in 1.2% children aged 1 to 3 years with most prevalence (P<0.05). Infection rates of type 3 parainfluenza in children < or =1 year, 1 to 3 years, and >3 years were 4.7%, 3.2% and 1.4% respectively with a significant difference (chi(2)(trend)=52.4, P<0.01). Although there were some differences of infection rate of RSV in different years, it tended to increase from November to next April with a highest rate of 62.8%. Type 3 parainfluenza virus and Type A influenza virus were almost sporadic while type A influenza virus was epidemic in August 2003 with an infection rate of 15.7%.
  
  
  
  The highest infection rate of viral pathogen of pneumonia in children is RSV and the follows are parainfluenza, influenza and adenovirus in turn.
authors.affiliation: The Affiliated Children's Hospital, College of Medicine, Zhejiang University, Hangzhou 310003, China. wtlchen@163.com
authors.forename: Tian-lin
authors.initials: TL
authors.lastname: Wang
authors.forename: Zhi-min
authors.initials: ZM
authors.lastname: Chen
authors.forename: Hong-feng
authors.initials: HF
authors.lastname: Tang
authors.forename: Lan-fang
authors.initials: LF
authors.lastname: Tang
authors.forename: Chao-chun
authors.initials: CC
authors.lastname: Zou
mesh_terms: D000256:Adenoviridae / Q000302:isolation & purification; D000258:Adenovirus Infections, Human / Q000821:virology; D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D009975:Orthomyxoviridae / Q000302:isolation & purification; D009976:Orthomyxoviridae Infections / Q000821:virology; D010252:Paramyxoviridae / Q000302:isolation & purification; D018184:Paramyxoviridae Infections / Q000821:virology*; D011024:Pneumonia, Viral / Q000821:virology*; D018357:Respiratory Syncytial Virus Infections / Q000821:virology*; D012136:Respiratory Syncytial Viruses / Q000302:isolation & purification