2016-2017年宁夏急性胃肠炎患者中诺如病毒感染状况及重组类型分析

Analysis of infection status and recombination types of norovirus in patients with acute gastroenteritis in the Ningxia Hui Autonomous Region from 2016 to 2017

目的了解宁夏急性胃肠炎患者中诺如病毒的感染状况及其重组现象。方法研究对象为2016年1月至2017年12月在宁夏5个市10家监测点医疗机构门急诊就诊的急性胃肠炎病例,共2 334例。收集病例临床资料和患者个人信息,采集粪便标本后统一送往宁夏疾病预防控制中心,采用实时荧光定量PCR方法进行核酸检测,采用逆转录PCR对诺如病毒GⅡ型阳性标本的聚合酶区和衣壳蛋白区进行扩增、测序及基因分型,用MEGA-X软件进行进化分析,并用Simplot 3.5.1和RDP4软件进行重组分析。结果2 334例病例的年龄M(P25,P75)为1.42(0.68,7.69)岁;2016和2017年分别为1 133和1 201例;男女分别为1 343和991例;诺如病毒GⅠ型阳性率为0.86%(20例),GⅡ型为14.82%(346例)。346株GⅡ型毒株中有78株重组毒株完成测序,共发现12种重组类型,其中GⅡ.Pe/GⅡ.4Sydney_2012和GⅡ.P12/GⅡ.3为主要流行株,分别占35.90%(28株)和32.05%(25株),其次为GⅡ.P16/GⅡ.2,占12.82%(10株);首次在宁夏检出GⅡ.P7/GⅡ.6(2株)、GⅡ.P12/GⅡ.3(6株)、GⅡ.P16/GⅡ.1(2株)、GⅡ.P16/GⅡ.2(5株)、GⅡ.Pe/GⅡ.4(7株)型重组株,均为型间重组,重组位点多位于ORF1区。结论2016-2017年宁夏诺如病毒感染以GⅡ组为主,且均为重组株,GⅡ.Pe/GⅡ.4Sydney_2012和GⅡ.P12/GⅡ.3为主要流行株,其次为GⅡ.P16/GⅡ.2。

Objective To analyze the infection status and recombination of Norovirus in patients with acute gastroenteritis in Ningxia. Methods The specimens of 10 sentinel hospitals in Ningxia were collected from 2016 to 2017. Real-time quantitative PCR was used for nucleic acid detection. GⅡ-positive samples were amplified by RT-PCR for the RdRp and Capsid regions, then sequenced and genotyped. Evolution analysis was performed using software such as MEGA-X, and recombination analysis was performed using Simplot 3.5.1 and RDP4. Results The age of the 2 334 cases was 1.42 (0.68, 7.69) years old, 1 133 cases in 2016 and 1 201 cases in 2017, 1 343 and 991 cases for males and females respectively. The positive rate of Norovirus GⅠ genogroup was 0.86%(20/2 334), and GⅡ genogroup was 14.82%(346/2 334). A total of 78 recombinant strains were sequenced and 12 recombinant types were found. GⅡ.Pe/GⅡ.4Sydney_2012 and GⅡ.P12/GⅡ.3 were the main epidemic strains, accounting for 35.90%(28 strains) and 32.05%(25 strain) respectively, followed by GⅡ.P16/GⅡ.2 accounting for 12.82%(10 strains). Among them,GⅡ.P7/GⅡ.6 (2 strains), GⅡ.P12/GⅡ.3 (6 strains), GⅡ.P16/GⅡ.1 (2 strains), GⅡ.P16/GⅡ.2 (5 strains), GⅡ.Pe/GⅡ.4 (7 strains) were detected for the first time in Ningxia. Recombinant strains were all intergenotype recombination, and the recombination breakpionts were all located within ORF1. Conclusion Norovirus infection in Ningxia area was mainly in GⅡ genogroup from 2016 to 2017, and most of them were recombinant strains. GⅡ.Pe/GⅡ.4Sydney_2012 and GⅡ.P12/GⅡ.3 were the main epidemic strains, followed by GⅡ.P16/GⅡ. 2.