title: [Analysis of pathogenic features and infection status of human parainfluenza virus type 3 among children in Hangzhou].
abstract: OBJECTIVE
  To determine the level of genetic variation of human parainfluenza virus type 3 (HPIV-3), and to describe infection and co-infection characteristics of HPIV-3 in children.
  
  
  METHODS
  Single respiratory samples from 856 pediatric patients with acute respiratory tract infection (ARI) in Hangzhou were collected from December 2009 to March 2013. All samples were screened for HPIV-3 by real-time RT-PCR and followed by HN sequencing and phylogenetic analysis. In all RSV positive specimens, we screened for the other pathogens, and co-infection characteristics were evaluated.
  
  
  RESULTS
  A total of 9.6% of 856 samples were positive for HPIV-3, the nucleotide among the strains ranged from 96.9% to 100%. All Hangzhou strains were placed in C3 subgroup based on HN gene analysis. 49% (n=41) of all HPIV-3-positive children with ARI were found to be co-infected with at least one of the other pathogen. The highest co-infection rate of HPIV-3 was with HRV (n=17). Children in the younger groups (≤12 months old) were significantly more prone to be co-infected with other pathogen (χ(2)=4.78, P=0.029). Pneumonia infection rate was significantly higher in the mono-infection group than the co-infection group (χ(2)=3.92, P=0.048).
  
  
  CONCLUSIONS
  HPIV-3 was an important pathogen in children with ARI in Hangzhou. HN gene variation rate was low, but showed a more local pattern. The co-infections with other respiratory viruses were popular. Except for pneumonia, no significant differences in other clinical presentation between the HPIV-3 mono-infection and co-infection groups were observed.
authors.affiliation: Microbiology Laboratory, Hangzhou Center for Disease Control and Prevention, Hangzhou 310021, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Qian
authors.forename: Xinfeng
authors.initials: X
authors.lastname: Yu
authors.forename: Min
authors.initials: M
authors.lastname: Zhao
authors.forename: Yu
authors.initials: Y
authors.lastname: Kou
authors.forename: Jun
authors.initials: J
authors.lastname: Li
authors.forename: Yinyan
authors.initials: Y
authors.lastname: Zhou
mesh_terms: D002648:Child; D002681:China / Q000453:epidemiology; D014644:Genetic Variation; D006801:Humans; D010224:Parainfluenza Virus 3, Human; D010802:Phylogeny; D060888:Real-Time Polymerase Chain Reaction; D012141:Respiratory Tract Infections / Q000453:epidemiology / Q000821:virology*; D010253:Respirovirus Infections / Q000453:epidemiology*