Detection and analysis of human bocavirus in children with acute respiratory infection in Nanjing / 中华检验医学杂志

ABSTRACT

Objective To investigate the possible existence of HBoV in children with acute respiratory infections in Nanjing area and explore its relationship with clinical characteristics.Methods A total of 397 nasopharyngeal secretion samples were collected from children with acute respiratory infection,admitted from July 2009 to June 2010 in Nanjing Children'S Hospital affiliated to Nanjing Medical University,and 50 cases of children without symptoms of respiratory infection were recruited as control group,whose nasopharyngeal secretion samples were also collected.HBoV was determined by real-time fluorescence quantitative PCR.MP and CT were detected by real-time fluorescence quantitative PCR in those HBoV-positive samples.RSV,ADV,IVA,IVB,PIV-1,PIV-2,PIV-3 and hMPV were detected by direct antigen-specific immunofluorescence assays.HBoV NP-1 fragments were amplified and sequenced in 5 HBoV positive samples randomly selected.The results were compared with the known GenBank sequence,and thereby the phylogenetic tree was established.The epidemiological characteristics,clinical presentation and the final clinical diagnosis of HBoV were analyzed according to the clinical data of the HBoV-positive patients.Results Thirty-three HBoV-positive cases were detected by real-time fluorescence quantitative PCR method with a positivity rate of 8. 3% ( 33/397 ). Among the 33 HBoV-positive cases, 19 cases (57.6%) were multiple infections with HBoV and other pathogens, the top three of which were MP (27.3% ,9/33 ),RSV (24.2% , 8/33 ) and PIV-3 ( 12. 1% ,4/33 ). Affected children aged from 7 to 36 months old accounted for 75.8% of the total ( 25/33 ). The measured HBoV NP-1 gene sequences of 5 specimens were consistent,indicating a high homology (99% to 100% ) with the stl, st2 and WHL-1. Conclusions HBoV is one of the pathogens of children's acute respiratory infections in Nanjing. HBoV NP-1 gene is highly conserved,with little variation in different seasons and in different regions and therefore can be used as a marker for real-time fluorescence quantitative PCR and other methods.