Clinical Study Of Acute Lower Respiratory Tract Infection Caused By Respiratory Syncytial Virus Of Different Genotypes In Children

1 Background Respiratory syncytial virus(RSV)is a common pathogen that causes acute lower respiratory tract infection(ALRTI)in children,worldwide,and is also the leading cause of hospitalization and mortality,placing a great economic burden on families and society’s health system.So far,the epidemiology of RSV in Shenzhen Guangdong province has not been clarified.And there is still great controversy at home and abroad about the clinical characteristics of ALRTI caused by different genotypes of RSV,so exploring whether there are differences in its epidemic characteristics and clinical manifestation of RSV of various genotypes would provide a certain theoretical basis for clinical practice and has important clinical significance.2 Objectives To explore the epidemiology of RSV in hospitalized children in the department of Pediatric Respiratory and Critical Care Unit of the Affiliated Shenzhen Maternity and Child Healthcare Hospital,Southern Medical University,Shenzhen,Guangdong,province,and whether there are differences between distinct molecular characteristics and clinical manifestations during the novel coronavirus epidemic,which provides a theoretical basis for the prevention and treatment of RSV-induced ALRTI in children.3 Methods Nasopharyngeal swab specimens of children with ALRTI by RSV infection from June 2021 to September 2021 in the Department of Pediatric Respiratory and Critical Care Unit of the Affiliated Shenzhen Maternity and Child Healthcare Hospital,Southern Medical University,Shenzhen,Guangdong,province were collected and sequenced to clarify the subtypes of RSV,and phylogenetic trees were constructed to further distinguish the genotypes,and the corresponding clinical data of children,including basic information,clinical symptoms,physical examination,laboratory and imaging results,treatments,outcomes were collected,and SPSS 26.0 was used for stratification analysis of clinical features of different genotypes.4 Results 380 children who met the inclusion and exclusion criteria were included in the study period,of whom 217(57.1%)were positive for RSV,with no statistical difference in the positive detection rate between males and females,while the highest rate of RSV detection was found in children 0-6 months of age,which was statistically different from the three groups of 3-6 years and 6-14 years(χ2=23.563,P<0.001;χ2=9.306,P=0.002).51 nasopharyngeal swab specimens successfully distinguished RSV-A and RSV-B subtypes,of which 27(52.9%)were RS V-A and 24(47.1%)were RSV-B.Clinical characteristics analysis of children infected by different subtypes and genotypes causing ALRTI showed statistically significant differences were found in the number of hospital days(P=0.048)and the proportion of PICU admission(P=0.008)between children infected with the RSV-A subtype ON1 genotype and those infected with the RSV-B subtype BA9 genotype.Children with A LRTI caused by RSV-A subtype ON1 genotype have longer hospital stays and a higher proportion of admission to PICU.while there was no significant correlation between RSV molecular and disease severity score(Spearman’s rho =-0.026,P=0.626).5 Conclusions From June 2021 to September 2021 in our department,there was no difference in the positive detection rate between male and female of RSV infection cases of inpatient children,while the inf ection rate was higher in children aged 0-6 months.Mainly RSV-A subtypes during the study period,RSV-B subtypes were cocirculating.RSV-A subtypes were all ON1 genotypes,RSV-B subtypes were BA9 genotypes,and children infected with RSV-A subtype and ON1 genotype may have longer hospital stays and higher proportion of PICU admission,but there was no clear association with disease severity scores.