下呼吸道不同基因型呼吸道合胞病毒感染患儿病情及与哮喘的关系

Severity of illness in children with lower respiratory tract infections caused by respiratory syncytial virus with different genotypes and its relationship with asthma

目的探讨下呼吸道不同基因型呼吸道合胞病毒(RSV)感染患儿病情严重程度及与哮喘的关系。方法选取2018年1月-2020年6月因急性下呼吸道感染(ALRTI)就诊且RSV阳性的14岁以下儿童86例,扩增G基因并测序,统计不同基因型RSV感染患儿病情严重程度,并按是否发生哮喘分为哮喘组与非哮喘组,比较两组RSV基因型,总结下呼吸道感染RSV流行及遗传变异特征。结果86份RSV阳性标本共检出A亚型40株,B亚型46株,2018年1月-2020年6月RSV流行亚型转换模式为B亚型、A亚型、B亚型,2018年、2020年以RSV B亚型为优势亚群,2019年A亚型为优势亚型;A亚型以NA1型基因型(75.00%)为主,其次为ON1型(20.00%);B亚型以BA9基因型为主(76.09%),其次为BA8基因型(10.87%),且不同年度RSV感染均以冬春季节为主;感染RSV A亚型NA1基因型患儿年龄低于B亚型BA9基因型患儿(P<0.05),住院时间较B亚型BA9基因型患儿长,哮喘严重程度评分高于B亚型BA9基因型患儿(P<0.05),吸氧比例、发生哮喘比例高于B亚型BA9基因型患儿(P<0.05);A亚型NA1基因型感染患儿病情严重程度分级高于B亚型BA9基因型感染患儿(P<0.05);86例患儿共发生哮喘27例,哮喘发作率为31.40%,哮喘组RSV A亚型NA1基因型比例(55.56%)高于非哮喘组(25.42%)(P<0.05)。结论ALRTI患儿RSV感染A亚型以NA1基因型为主,B亚型以BA9基因型为主,冬春季节多发,RSV A亚型、B亚型呈交替流行;NA1基因型RSV感染患儿病情严重程度高,进展为哮喘风险更大,需引起临床重视。

OBJECTIVE To investigate the relationship between the severity of illness and asthma in children with lower respiratory tract infections caused by respiratory syncytial virus(RSV)with different genotypes.METHODS 86 RSV positive children under 14 years old who were treated for acute lower respiratory tract infection(ALRTI)between Jan.2018 and Jun.2020 were selected.The G gene was amplified and sequenced,and severity of children with different genotypes of RSV infections was statistically analyzed.According to the presence or absence of asthma,the subjects were divided into asthma group and non-asthma group.The RSV genotypes between the two groups were compared,and the RSV prevalence and genetic variation characteristics of lower respiratory tract infections were summarized.RESULTS A total of 40 strains of subtype A and 46 strains of subtype B were detected in the 86 RSV-positive specimens.From Jan.2018 to Jun.2020,the RSV epidemic subtype conversion mode was subtype B,subtypes A and subtype B.In 2018 and 2020,RSV subtype B was the dominant subtype,and subtype A was the dominant subtype in 2019.Genotype NA1(75.00%)was the most common in subtype A,followed by ON1(20.00%).However,subtype B was dominated by genotype BA9(76.09%),followed by genotype BA8(10.87%),and RSV infections in different years mainly occurred in winter and spring.Children infected with RSV subtype A genotype NA1 were significantly younger than those with subtype B genotype BA9 of infection(P<0.05),and their hospital stay was significantly longer than children with subtype B genotype BA9,and their asthma severity scores were significantly higher than children with subtype B genotype BA9(P<0.05).Besides,the proportion of oxygen inhalation and the incidence of asthma were significantly higher than those of children with subtype B genotype BA9(P<0.05).The grade of infection severity of children infected with subtype A genotype NA1 was significantly higher than those of children infected with subtype B genotype BA9(P<0.05).A total of 27 cases of asthma occurred in 86 children,with the asthma attack rate of 31.40%.The proportion of RSV subtype A genotype NA1 in the asthma group(55.56%)was significantly higher than that in the non-asthma group(25.42%)(P<0.05).CONCLUSION In children with ALRTI,the subtype A of RSV infection was dominated by genotype NA1,and the subtype B was dominated by the genotype BA9,which was more frequent in winter and spring.RSV subtype A and subtype B were alternately prevalent.Children with genotype NA1 of RSV infection had a high degree of severity and a greater risk of developing asthma,which requires clinical attention.