Objective: To analyze the epidemiological and molecular characteristics of human brucellosis in Qinghai province from 2005 to 2019 and provide basic data for brucellosis prevention and control. Method: The data about human brucellosis in Qinghai from 2005 to 2019 were collected from the information system of China CDC to describe the spatial, population and time distributions of human brucellosis cases in Qinghai. The isolated strains were identified and typed with traditional methods, BCSP31-PCR, AMOS-PCR and multi-locus variablenumber tandem repeat (MLVA-16). Results: A total of 577 human brucellosis cases were reported in Qinghai from 2005 to 2019, the average prevalence rate was 0.07 per 100 000 person, there were statistic differences among different years. The disease occurred all the year around, but mainly during March-October. The 577 cases were distributed in 31 counties (cities/districts) from 6 autonomous prefectures (cities). The prevalence rats of five counties were high, i.e. Menyuan Hui autonomous county (22.88%, 132/577), Tianjun county (10.57%, 61/577)、Xining city (10.57%, 61/577), Henan Mongol Autonomous County (10.51%, 58/577) and Haiyan county (9.53%, 55/577). Age of the cases ranged from 8 years to 82 years, and the male to female ratio of the cases was 1.8∶1 (374/203). The prevalence rate in herdsman (47.83%, 276/577) was highest among different occupational populations. Ten isolates were all Brucella melitensis strains, belonging to biovar 3, and clustering analysis indicated that the 10 strains had 5 genotypes, in which 2 were distinct, the remaining 3 were same. MLVA-16 analysis indicated that the 10 strains had close relationship with 26 B. melitensis strains isolated in Qinghai previously. Conclusions: The prevalence of brucellosis increased in Qinghai in recent years, we should strengthen the population based brucellosis surveillance and reporting. MLVA-16 indicated the gene diversity of the Brucella strains, suggesting that MLVA-16 can be used for genetic diversity analysis and molecular epidemiology survey to improve brucellosis surveillance.
目的： 分析青海省人间布鲁氏菌病（布病）流行规律与趋势，对2005-2019年布鲁氏菌分离株进行分子分型，为制定青海省布病预防控制策略提供依据。 方法： 收集中国疾病预防控制信息系统青海省2005-2019年布病报告数据，描述和分析其时间、地区和人群三间分布。采用BCSP31聚合酶链式反应（BCSP31-PCR）、AMOS聚合酶链式反应（AMOS-PCR）和多位点串联重复序列分析（MLVA-16）方法鉴定布鲁氏菌分离株，进行聚类分析。 结果： 2005-2019年青海省累计报告病例577例，平均发病率为0.07/10万，不同年份差异有统计学意义。一年四季均可发病，集中在每年的3-10月。577例病例分布在6个自治州（市）的31个县（市、区）中，病例数位居前5位的是门源回族自治县（22.88%，132/577）、天峻县（10.57%，61/577）、西宁市（10.57%，61/577）、河南蒙古族自治县（10.51%，58/577）和海晏县（9.53%，55/577）。年龄范围8~82岁，男女性别比为1.8∶1（374/203），职业分布以牧民为主（47.83%，276/577）。从人全血中分离的10株菌株均为羊种Ⅲ型布鲁氏菌，分为5种基因型（2种基因型为单基因型，3种基因型为相同基因型），MLVA-16分型和聚类分析结果显示，同青海省已发表文献的26株羊种Ⅲ型布鲁氏菌的遗传关系较近。 结论： 青海省布病疫情呈回升趋势，应加强人群监测和疫情通报，MLVA-16分型呈基因多态性，提示MLVA-16可用于遗传多样性分析和分子流行病学溯源调查，以提高布病监测能力。.
Keywords: Brucellosis; Epidemiological characteristics; Multi-locus variable number tandem repeat analysis.