ABSTRACT
Objective To investigate the viral prevalence of acute lower respiratory tract infection (ALRTI)in children. Methods Totally 1165 children with clinical diagnosis of ALRTI during the period from August 2007 to September 2008 were involved in our study. The nasopharyngeal aspirate specimen was collected from each patient. RT-PCRs were performed to detect common respiratory tract viruses including respiratory syncytial virus (RSV), rhinovirus (HRV), parainfluenza virus (PIV, type 1 -3 ), influzenza virus type A and B (IFA,IFB), and PCR was used to detect adenovirus (ADV). Results 783 patients were identified to have at least one kind of viral pathogens and the overall positive rate was 67.2%. The most common virus was RSV (27%), followed by HRV ( 17.4% ) and PIV3 ( 13. 9% ). The peak infection seasons were winter and autumn. The etiological spectrum of ALRTI varied in different age groups. Two or more viruses were identified in 284 out of 783 cases ( 36. 3% ). The mixed infection rate was high in infants under 1 year old (63.7%) while it decreased to 8. 5% in children older than 3 years of age. Conclusion RSV, HRV and PIV3 were the most predominant pathogens in children less than 1 year old. The peak infection seasons were winter and autumn. The infection rate and mixed infection rate in infants under 1 year old were highest. The most common style was RSV and HRV mixed infection.