摘要
目的调查了解2016-2018年陕西省炭疽流行情况、病原学特征及分子流行病学特征。方法对2016-2018年报告炭疽病例开展个案调查,进行流行病学三间分布分析;采集病例生物样本及环境样本,进行炭疽杆菌分离培养、炭疽ELISA抗体检测及荧光定量PCR检测,对分离到的阳性标本以canSNP及MLVA15的方法进行分子分型,与陕西省历史菌株及国内部分省份菌株基因型进行聚类分析。结果 2016-2018年陕西省共炭疽病例14例,发病到诊断平均9天,地理分布以关中及陕北地区为主,8月份发病较多,人群分布性别比为6∶1(12/2),26~59岁占85.7%(12/14),农民占71.4%(10/14)。人体标本病原培养17份,分离到炭疽杆菌1株,阳性5.9%,环境标本培养77份均为阴性,ELISA检测阳性率83.3%(10/12),荧光定量PCR阳性率21.4%(3/14);陕西省炭疽菌株canSNP基因型为A.Br.001/002型,2015年、2018年及1953年菌株MLVA分型分别为MLVA15-38、31、CHN17基因型。结论 2016-2018年陕西省炭疽疫情属较低散发水平,主要分布在关中及陕北地区,8月为发病高峰,人群以青壮年男性农民为主。炭疽杆菌canSNP基因型为A.Br.001/002,与国内主要流行株相同。存在3种不同的MLVA15基因型。陕北地区MLVA15-38型,与北部内蒙古相近;关中地区MLVA15-31型,与甘肃省及新疆类似;历史上还曾有MLVA15-CHN17型。
Objective To investigate the epidemic situation,etiological characteristics and molecular epidemiological characteristics of anthrax in Shaanxi Province from 2016 to 2018.Methods We used case investigation of anthrax cases reported in 2016-2018 and epidemiological analysis of spatial,temporal and population distribution.Biological samples and environmental samples were collected for B.anthracis isolation culture,anthrax ELISA antibody detection and real-time PCR detection.The positive samples were molecularly typed by canSNP and MLVA15,and clustered with the historical strains of Shaanxi Province and the genotypes of some domestic provinces.Results A total of 14 cases were reported from 2016 to 2018 in Shaanxi Province.The average time from onset to diagnosis was 9 days.The geographical distribution was mainly in Guanzhong and Northern Shaanxi.There were more cases in August.The sex ratio of population distribution was 6:1(12/2).85.7%(12/14)were 26-59 years old,and 71.4%(10/14)were peasants.One strain of Bacillus anthracis was isolated from 17 human specimens,and the positive rate was 5.9%.77 environmental specimens were negative.The positive rate of ELISA was 83.3%(10/12).The positive rate of fluorescence quantitative PCR was 21.4%(3/14).CanSNP genotype of anthrax strain in Shaanxi Province was A.Br.001/002.MLVA genotypes of strains isolated in Shaanxi Province in 2015,2018 and 1953 were MLVA15-38,31 and CHN17 genotypes,respectively.Conclusion The anthrax epidemic in Shaanxi Province in 2016-2018 is at a low emission level.The cases are mainly distributed in Guanzhong and Northern Shaanxi.August is the peak incidence.The distribution of the population is dominated by young male farmers.The canSNP genotype A.Br.001/002 of Bacillus anthracis in Shaanxi Province is the same as that of the main domestic strains,and there are three different MLVA15 genotypes.MLVA15-38 in Northern Shaanxi is similar to Inner Mongolia.MLVA15-31 in Guanzhong is similar to Gansu Province and Xinjiang Province.There have also been MLVA15-CHN17 models in history.
引文
[1] Chen WJ,Lai SJ,Yang Y,et al.Mapping the distribution of anthrax in mainland China,2005-2013[J].PLOS Neglected Tropical Diseases,2016,10(4):e0004637.
[2] Keim P,Price LB,Klevytska AM,et al.Multiple-locus variable-number tandem repeat analysis reveals genetic relationships within Bacillus anthracis[J].Journal of Bacteriology,2000,182(10):2928-2936.
[3] Ert MN,Easterday WR,Huynh LY,et al.Global genetic population structure of Bacillus anthracis[J].PLOS One,2007,2(5):e461.
[4] 王秉翔,SmithKL,Keys,等.中国的炭疽杆菌DNA分型及其地理分布[J].微生物学免疫学进展,2002,30(1):14-17.
[5] 魏建春,张恩民,张慧娟,等.中国炭疽芽胞杆菌中11个串联重复序列位点的特征和分布[J].中国人兽共患病学报,2012,28(8):765-768.
[6] 毛玲玲,田疆,雷露,等.辽宁省炭疽芽胞杆菌MLVA分型研究[J].中国人兽共患病学报,2015,31(3):232-234.
[7] 谈忠鸣,张忠献,董晨,等.一起皮肤炭疽疫情中炭疽杆菌分子特征分析[J].南京医科大学学报:自然科学版,2015,35(3):436-438.
[8] 刘东立,朱妮,马国柱,等.陕西省炭疽流行病学回顾性分析及防治对策探讨[J].中华疾病控制杂志,2017,21(1):52-55.
[9] Liu DL,Wei JC,Chen QL,et al.Genetic source tracking of an anthrax outbreak in Shaanxi province,China[J].Infectious Diseases of Poverty,2017,6:14.
[10] 中华人民共和国卫生部.WS 283-2008 炭疽诊断标准[S].北京:人民卫生出版社,2008.
[11] World Health Organization.Anthrax in humans and animals[M].Geneva:World Health Organization,2008.
[12] 刘东立,李文涓,石一,等.TaqMan-LNA探针多重实时荧光定量PCR检测炭疽芽胞杆菌的研究[J].中国病原生物学杂志,2018,13(3):244-248,258.
[13] Zhang HJ,Zhang EM,He JR,et al.Genetic characteristics of Bacillus anthracis isolated from northwestern China from 1990 to 2016[J].PLOS Neglected Tropical Diseases,2018,12(11):0006908.
[14] 章文婧,李青华,王勇,等.2007~2011年中国皮肤炭疽流行病学分析[J].军事医学,2013,37(12):892-894.
[15] 周宇,张熙,李香,等.2006-2015年全国动物炭疽流行分析及防控[J].中国兽医学报,2018,38(2):336-340.
[16] 梁旭东,于德山,吕卫民,等.炭疽防控存在的问题及对策建议[J].疾病监测,2017,32(4):278-281.
[17] 吕卫民,于德山,周卫忠,等.2005-2016年甘肃省炭疽流行病学特征分析[J].疾病监测,2017,32(5):402-404.
[18] 马青,李世军,刘英,等.贵州省2006-2011年炭疽芽胞杆菌检出情况与致病性研究[J].中国人兽共患病学报,2014,30(6):632-635.
[19] Simonson TS,Okinaka RT,Wang B,et al.Bacillus anthracis in China and its relationship to worldwide lineages[J].BMC Microbiology,2009,9:71.