2017-2019年我国炭疽流行特征及炭疽芽胞杆菌分子分型分析

Analysis of epidemic characteristics of anthrax in China from 2017 to 2019 and molecular typing of Bacillus anthracis

目的探讨2017—2019年我国炭疽流行特征及发病规律,对部分省份(自治区)的炭疽芽胞杆菌进行分子分型分析。方法收集中国疾病预防控制传染病监测信息系统和突发公共卫生事件报告管理信息系统中2017—2019年报告的炭疽发病资料,采用描述性流行病学方法分析流行特征和时间、地区及人群分布情况;以2017—2019年分离的47株炭疽芽胞杆菌作为研究对象,应用经典单核苷酸多态性分析(canSNP)和15个位点的可变数量串联重复序列分析(MLVA15)方法对炭疽芽胞杆菌进行分子分型分析。结果2017—2019年共报告的炭疽病例数为951例,其中938例是皮肤炭疽,达到总报告数的98.63%,分布地区主要在我国西部和东北地区,累计病例数前三位的省份是甘肃(215例)、四川(202例)和青海(191例);全年均有病例报告,夏秋季发病较多,8月份达到发病高峰,2017—2019年的6至10月份发病数分别占全年发病数的66.35%(211/318)、72.32%(243/336)和68.01%(202/297);年龄范围分布主要在20~59岁,约占总病例数的80%以上;男性病例明显多于女性,男女性别比约为3∶1。职业以牧民和农民为主,牧民病例占当年全部报告发病数的49.70%~58.18%,农民病例占当年全部报告发病数的31.45%~36.70%。每年均有突发公共卫生事件报告,2017—2019年共报告29起突发公共卫生事件。canSNP分析显示,47株菌中有37株属于A.Br.001/002亚群,10株属于A.Br.Ames亚群。MLVA15分析显示,测试菌株可以分成17个基因型,其中有10个基因型只包括1株菌。结论我国2017—2019年炭疽主要以皮肤炭疽为主,有明显地区性、季节性和人群分布特征;canSNP和MLVA15等分子分型方法可以在传染病溯源工作中发挥作用,为炭疽的预防控制提供技术支持。

Objective To analyze the epidemiological characteristics of anthrax in China from 2017 to 2019 and molecular typing of Bacillus anthracis isolated from some provinces(autonomous regions).Methods Surveillance data of anthrax cases reported from 2017 to 2019 in the Infectious Disease Surveillance information System of China Disease Prevention and Control and the Public Health Emergency Reporting and Management Information System were collected,and descriptive epidemiological methods were used to analyze the epidemic characteristics,including the temporal,geographic and demographic distribution of this disease.A total of 47 strains of Bacillus anthracis isolated from 2017 to 2019 were analyzed by canSNP and MLVA15.Results A total of 951 cases of anthrax were reported from 2017 to 2019,of which 938 were cutaneous anthrax,representing 98.63%of the total number reported.It was mainly distributed in the west and northeast of China,and the three provinces with the highest number of cases were Gansu(215),Sichuan(202)and Qinghai(191).Cases had been reported throughout the year,more cases occurred in the summer and autumn,and August was the month with the most cases,66.35%(211/318),72.32%(243/336)and 68.01%(202/297)of cases were reported during June to September.The age distribution was mainly between 20 and 59 years old,accounting for more than 80%of all cases.The number of male cases was significantly higher than that of female cases,the ratio of male to female was about 3∶1.The occupations were mainly herdsmen and farmers,accounting for 49.70%to 58.18%and 31.45%to 36.70%,respectively.Public health events occurred every year,and 29 events had been reported from 2017 to 2019.canSNP analysis showed that 37 of the 47 strains belonged to the A.Br.001/002 subgroup and 10 belonged to the A.Br.Ames subgroup.MLVA15 analysis showed that there were 17 genotypes,of which 10 genotypes contained only one strain.Conclusion Cutaneous anthrax was the predominant clinical type in China from 2017 to 2019.The seasonal,geographic and demographic distribution characteristics were evident.Molecular typing methods such as canSNP and MLVA15 can be used to trace the source of infectious diseases and provide technical support for anthrax prevention and control.