南京市鼻病毒感染暴发疫情流行病学及病原学特征

Epidemiological and etiological characteristics of human rhinovirus infection outbreak in Nanjing

目的分析南京市鼻病毒(human rhinoviruses,HRV)感染暴发疫情的流行病学及病原学特征。方法2020年5—6月,南京市江北新区、雨花台区发生HRV感染暴发疫情3起,采集有HRV感染症状人群的咽拭子样本,排除新型冠状病毒及流感病毒感染后,采用实时荧光定量PCR方法检测HRV核酸,用巢式PCR扩增HRV的VP4/2的靶基因,测序后鉴定阳性HRV样本血清型。从GenBank数据库下载HRV各血清型参考株的序列资料,使用MEGA6和BioEdit等软件将测序结果与参考株进行比较分析。结果累计收集咽拭子样本33份,核酸阳性率60.00%~87.50%,共鉴定出13种血清型,对HRV各组内的核苷酸同源性进行分析,HRV-A组内核苷酸的同源性为75.20%~100.00%,HRV-C组内核苷酸的同源性为72.70%~100.00%。HRV-A组是造成的疫情的主要致病原,HRV-A11和HRV-A29是造成的个体感染数最多的血清型,存在同一起疫情检测出多种血清型的现象。结论HRV疫情存在多种血清型共流行,A组为主要病原,A11和A29为主要流行的血清型。在不同血清型之间没有交叉免疫,要不断对HRV导致的呼吸道疫情进行深入研究,加强对HRV感染的监测,为HRV的诊断和疫情防控提供科学依据。

Objective To analyze the epidemiological and etiological characteristics of human rhinoviruses(HRV)infection outbreak in Nanjing,so as to provide evidence for the prevention and control of HRV in Nanjing.Methods For emergency response to three HRV infection clustering epidemics in two districts(Jiangbei New District and Yuhuatai District)in Nanjing in May to June,2020,oropharyngeal swab samples of the symptomatic people were collected and tested for HRV nucleic acid using real-time fluorescence quantitative polymerase chain reaction(PCR)after ruling out severe acute respiratory syndrome coronavirus 2 infection and influenza virus infection.Nested PCR was used to amplify the target gene of VP4/2 of HRV,and the serotypes of HRV-positive samples were identified by sequencing.Sequence data of reference HRV strains of various serotypes were downloaded from GenBank database,against which the sequencing results were compared with MEGA6 and BioEdit software.Results 33 oropharyngeal swab samples were collected.The positive rate of nucleic acid testing the 3 outbreaks was 60.00%-87.50%.A total of 13 serotypes were identified.Nucleotide homology analysis showed that HRV-A group shared 75.20%-100.00%homology,and HRV-C group shared 72.70%-100.00%homology.HRV-A group was the main pathogens of the epidemics,in which HRV-A11 and HRV-A29 were the serotypes causing the largest number of individual infections.There were multiple serotypes detected in a single outbreak.Conclusions Multiple serotypes co-circulate in outbreaks of HRV infection,in which group A may be the main pathogen,and A11 and A29 the dominant serotypes.However,due to the absence of cross-immunity among different serotypes,it is necessary to continuously conduct in-depth research on respiratory tract infection epidemics caused by HRV,strengthen the monitoring of HRV infection,so as to provide scientific evidence for the diagnosis of HRV and epidemic prevention and control.