Etiology of acute viral respiratory infections in children

Objective To investigate the status of viral pathogens of acute respiratory infections in the children treated in Zhongshan BoAi Hospital.Methods A total of 9 459 nasopharyngeal secretion samples were collected from December 2011 to November 2012 in Zhongshan Boai Hospital.Direct immunefluorescence technique was used to detect seven common respiratory viruses,including respiratory syncytial virus(RSV),adenovirus(ADV),influenza virus A and B,parainfluenza virusⅠ,Ⅱ,Ⅲ.The prevalence of various viral infections were analyzed in terms of season,age,sex and geographical region.Results In9 459 cases of acute respiratory infections in children,viral pathogen was positive in 2 429(25.7%)cases,including RSV1 104(45.5%),influenza virus A411(16.9%),parainfluenza virusⅢ 316(13.0%),influenza virus B290(11.9%),ADV275(11.3%),parainfluenza virusⅠ29(1.2%),parainfluenza virusⅡ4(0.2%).RSV infections occurred mainly in winter and spring.The prevalence of RSV infection varied significantly with age groups.The prevalence of RSV infections in children above 6 years of age was significantly lower than that in the children younger than6 years of age.Mixed infection with2 or more viruses was identified in 57 cases(2.3%),of which 49(84.2%)infected with 2 viruses,9(15.8%)infected with 3 viruses.RSV was the most frequently isolated virus in the mixed viral infections.The most common pattern of mixed infection was RSV plus parainfluenza virusⅢ(16 cases,28.1%).Conclusions RSV is the most important viral pathogen of acute respiratory infections in the children treated in Zhongshan Boai Hospital.RSV infection usually develops in winter and spring,especially in infants under one year of age.The prevalence of RSV reduces gradually with age.The prevalence of ADV is 11.3%,higher than previously reported data at home and abroad.This may suggest the increasing prevalence of ADV in the children with acute respiratory infections in recent years.