Identified And Pathogenic Study On Human Bocavirus In Children With Wheezing In East Guangdong

Objective:To investigate the possible existence of human Bocavirus in Guangdong province children with acute wheezing,explore its clinical features and virology features,provide theoretical basis for clinical.Materials and methodsFrom April 2007 to October 2007, 246 nasopharyngeal aspirate (NPA) or nasal swab samples from pediatric patients with acute wheezing, and 83 nasal swab samples from healthy children at routine physical examination were selected to test for Human Bocavirus(HboV) and other respiratory track viruses using the multiplex polymerase chain reaction (MPCR).The HboV positive PCR products with the correct expected molecular mass were randomly selected for sequencing, and sequences from these PCR products were compared to the sequences provided in GenBank.Results163 samples showed positive for at lest one virus of the 246 sampes(62.6%).Thirteen samples from 246 patients (5.3%) showed the expected PCR products, suggesting they were positive for HBoV. Age distribution of the children positive for HBoV mainly within 1 years (72.9%, 10/13), especially those younger than 5 months of age (53.8%, 7/13). Seven PCR amplicons were randomly selected for sequence analysis. They shared high nucleotide sequence homologies with HBoV reference strains Stockholm 1 (ST1),97.6 % to 98.5 %; ST2, 98.1% to 99.8%; WLL-1, 98.1% to 100%;, and among themselves, 97.3 % to 100% . The patient was diagnosed as asthma attack(1), pneumonia with acute wheezing(5) and bronchiolitis (7) accompanying with coughing,dyspnea and wheezing symptoms. Eight samples from the thirteen HBoV positive patients(61.5%) showed co-infection with orther viruses.No samples from the 83 healthy children were positive for HboV. Conclusion1.About 5.3% of children with acute wheezing in the east of Guangdong province was found HboV positive. Infants and young children, especially those younger than 1 year, are more likely to be infected by HBoV. The clinical features were related to pneumonia with acute wheezing and bronchiolitis.HBoV of different genotypes may co-circulate in children in east Guangdong. 2.The rate of co-infection is very high in the HBoV infection children. 3.We have not found HBoV infection in healthy children,HboV may not the natural virus in children.