title: High viral load of human bocavirus correlates with duration of wheezing in children with severe lower respiratory tract infection.
abstract: BACKGROUND
  Human bocavirus (HBoV) is a newly discovered parvovirus and increasing evidences are available to support its role as an etiologic agent in lower respiratory tract infection (LRTI). The objective of this study is to assess the impact of HBoV viral load on clinical characteristics in children who were HBoV positive and suffered severe LRTI.
  
  
  METHODS
  Lower respiratory tract aspirates from 186 hospitalized children with severe LRTI were obtained by bronchoscopy. HBoVs were detected by real-time PCR and other 10 infectious agents were examined using PCR and/or direct fluorescent assay.
  
  
  RESULTS
  Thirty-one patients (24.6%) were tested positive for HBoV in the respiratory tract aspirates. Fifteen samples had a high viral load (>10(4) copies/mL) and the other sixteen samples had a low viral load (<10(4) copies/mL). The duration of presented wheezing and hospitalization was longer in children with high viral load of HBoV than that in children with low viral load. The days of wheezing showed a correlation with viral load of HBoV.
  
  
  CONCLUSIONS
  We confirmed that HBoV was frequently detected in patients with severe LRTI. Wheezing was one of the most common symptoms presented by patients with positive HBoV. A high HBoV viral load could be an etiologic agent for LRTI, which led to more severe lower respiratory tract symptom, longer duration of wheezing and hospitalization.
authors.affiliation: Department of Respiratory Medicine, Children's Hospital, Chongqing Medical University, Chongqing, People's Republic of China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Deng
authors.forename: Xiaoyang
authors.initials: X
authors.lastname: Gu
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Zhao
authors.forename: Jian
authors.initials: J
authors.lastname: Luo
authors.forename: Zhengxiu
authors.initials: Z
authors.lastname: Luo
authors.forename: Lijia
authors.initials: L
authors.lastname: Wang
authors.forename: Zhou
authors.initials: Z
authors.lastname: Fu
authors.forename: Xiqiang
authors.initials: X
authors.lastname: Yang
authors.forename: Enmei
authors.initials: E
authors.lastname: Liu
mesh_terms: D052660:Bocavirus / Q000302:isolation & purification* / Q000502:physiology; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D010322:Parvoviridae Infections / Q000175:diagnosis*; D012135:Respiratory Sounds / Q000503:physiopathology*; D012141:Respiratory Tract Infections / Q000503:physiopathology* / Q000821:virology*; D019562:Viral Load