Viral Etiologies And Epidemiology Of Acute Respiratory Infection In Hospitalized Children In Some Regions Of China

Objective:To understand viral etiologies and epidemiology of acute respiratory infection(ARI)hospitalized children in some regions of China,therefore providing evidences for the specific treatment and vaccination,prevention and control of viral acute respiratory infections for children in different areas.Method:This study prospectively enrolled 8209 cases of hospitalized children aged<14 years with ARI from 2012 to 2015 in three sentinel hospitals in Beijing,Chongqing and Guangzhou located in different regions of China.The demographic and clinical data were collated,and respiratory samples were collected to detect eight major respiratory viruses,including influenza virus,respiratory syncytial virus(RSV),rhino virus(RoV),parainfluenza virus(PIV),adenovirus(ADV),metapneumovirus(MPV),coronavirus(hCoV)and bocavirus(hBoV),and the detection method is PCR methods.The positive proportions of viral pathogens and epidemiological characteristics of cases with ARI were also analyzed.Result:1.In this study,a total of 4745 cases were positive for at least one of eight respiratory viruses.The overall positive proportion was 51.5%,with the highest in Chongqing(75.5%),Beijing and Guangdong were 52.2%and 42.6%respectively.2.RSV was the most prevalent virus(22.5%),followed by RoV(15.0%),PIV(13.3%),influenza virus(9.4%),hBoV(6.0%),ADV(5.8%),hCoV(3.0%)and MPV(2.5%).RSV,RoV and PIV ranked the top three viral pathogens of ARI in Beijing and Chongqing,whilst RSV,IFV and ADV were the top three in Guangzhou.3.The positive proportions of respiratory viruses were different by age groups of the patients.RSV,RoV and PIV were highest in children aged<2 years,respectively 30.5%,18.3%and 17.4%;Influenza virus and ADV were higher among 1 to 5-year old cases than that of other age group;The positive proportion of MPV significantly decreased in children aged>4 years.HBoV in 6 to 23-month children was significantly higher than that in other age groups,but there was no significant difference in hCoV by age groups.4.There are co-infections among respiratory pathogens.We found 1326 cases with co-infections,among them cases with two viruses is most common(n=1076,81.1%).RSV,RoV,and PIV were the most common among the patients with co-infections,and hBoV co-infected with other pathogens accounted for 65.9%of all bocavirus positive cases,which was the highest among all kinds of pathogens.5.Compared with negative cases,positive patients were more prone to pneumonia(P<0.001),and co-infections would increase the proportion of patients with pneumonia(P<0.001).Pneumonia symptoms in hBoV positive patients was highest,up to 81.4%.6.We found that most pathogens had seasonal peaks.Among them,RSV had obvious seasonal characteristics in three areas,and the incidence proportion was high in winter and spring.In addition,there was a significant seasonal variation of PIV in Chongqing,with a high incidence in spring and summer.Conclusion:Eight respiratory viruses were found positively in children with ARI,with respiratory syncytial virus had the highest positive proportion.Pathogenic spectrum has some differences in three provinces with different seasonal peak of pathogens in different regions.The cases with positive viral detection had a higher risk of pneumonia than that of negative cases.