Objective  To investigate the incidence human bocavirus (HBoV)

human metapneumovirus (hMPV) and other 9 respiratory viruses in bronchiolitis of children in Chongqing area and their clinical characteristics of such childhood bronchiolitis.    Methods  Human syncytial virus (RSV)

adenovirus (ADV)

influenza virus (Flu) A and B

parainfluenza virus (Para) 1

2

3

associated with respiratory disorders from nasopharyngeal secretion in 112 infants with bronchiolitis admitted in our hospital from November 2006 to March 2007 and from November 2007 to March 2008 were assayed with rapid immunofluorescence method. At the same time

NP-1 and NS1 gene of HBoV

F gene of hMPV and other genes of the left 8 viruses were also detected with PCR or RT-PCR．    Results  Clinical characteristics were significantly different between the bronchiolitic patients in the 2 years

such as their age

and clinical symptoms including fever

vomit and tachypnea. There were a dozen of respiratory viruses found in the nasopharyngeal secretion from 112 infants with bronchiolitis. The positive rate of the virus infection identified in the infants was 75%

45 of them (40.18%) were infected by single virus

and 39 cases (34.82%) were by mixed virus detection. Significant difference was found between the positive rate of the 2 years. Among these infants

RSV was most common followed by parainfluenza virus (PIV3) and rhinovirus (RV). There were 10 cases positive to HBoV and all were detected with other respiratory viruses.    Conclusion  These data suggest that there are more bronchiolitis infant positive to respiratory viruses in Chongqing region

characterized with complicated virus types and more concurrent infection. And the epidemic characteristic patterns are different even in 2 continuous years. RSV and hMPV are more common than HBoV as a primary pathogen in childhood bronchiolitis

and the later is always co-infected with other viruses.