What is already known about this topic?:Human brucellosis poses a serious threat to the health of residents in Shaanxi Province, China. What is added by this report?:Between 2015 and 2024, the annual incidence rate of human brucellosis in Shaanxi, China, remained at historically high levels, exhibiting a high-to-low gradient from north to south, and its influencing factors demonstrated spatiotemporal heterogeneity. What are the implications for public health practice?:Targeted surveillance and control strategies for human brucellosis should be implemented according to local epidemiological characteristics. Surveillance and early warning capacity in the high-risk areas must be strengthened, and differentiated prevention and control measures should be developed accordingly.

IntroductionHuman brucellosis is a severe public concern in Shaanxi Province, China, and investigating the epidemiological relationship and transmission pattern of B. melitensis is necessary to devise control strategies.MethodsIn this study, a conventional bio-typing approach and whole genome sequencing of single-nucleotide polymorphisms (SNPs) were employed to identify 189 strains.ResultsBased on the conventional bio-typing, 189 Brucella strains were identified as B. melitensis, of which 14 were in bv. 1, 145 were in bv. 3, and 30 were variant, and the Brucella strains were distributed in all ten cities in Shaanxi Province. SNP analysis was used to identify genetic variation in 189 B. melitensis genomes, and maximum-likelihood was used to generate a phylogeny that identified two clades (A and B) and 19 sequence types (STs). The two clades were highly diverse and exclusively of Eastern Mediterranean origin. Clade B contained 18 STs (2-19), with most isolates originating from a broad swath, implying that multiple B. melitensis lineages circulated in Shaanxi. The 19 STs were composed of 3 to 46 strains isolated from different counties and years, suggesting that multiple cross-county brucellosis outbreak events are driven by multiple B. melitensis lineages. Global phylogenetic analysis revealed that clade A was close to GTIIb, and clade B was placed in the GTIIh lineage, expanding the known diversity of B. melitensis from China.ConclusionThe human brucellosis epidemic in Shaanxi is driven by multiple indigenous circulating B. melitensis lineages, the knowledge of which will contribute to devising a control strategy and providing the foundation for a comprehensive regional phylogeny of this important zoonotic pathogen.

With the booming of worldwide agriculture intensification, brucellosis, one of the most neglected zoonotic diseases, has become an increasing challenge for global public health. Although the transmission patterns of human brucellosis (HB) have been studied in many regions, the dynamic transfer processes of risk and its driving factors remain poorly understood, especially in the context of agricultural intensification. This study attempted to explore the risk transfer of HB between the exact epidemic areas and the neighboring or distant low-risk areas to explain the impact of livestock agriculture intensification and foodborne infections on the transmission of HB in Shaanxi Province as a case study. We adopted multiple approaches, including test-based methods, model-based methods, and a geographical detector to detect the spatial-temporal dynamic changes of high-risk epidemic areas of HB at the county scale. We also quantitatively estimated how the related factors drove the risk transfer of the disease. Results confirmed the risk transfer pattern of HB with an expansion from north to south in Shaanxi Province and identified two primary transfer routes. In particular, in the traditional epidemic areas of the Shaanbei plateau, the farm agglomeration effect can significantly increase the risk of HB. Meanwhile, retail outlets for milk and dairy products were partially responsible for the foodborne infections of HB in the emerging epidemic areas of Xi'an. This study not only contributed helpful insights to support HB control and prevention in the rapid transition of livestock agriculture but also provided possible directions for further research on foodborne HB infections in urbanized areas.

Objective:To analyze the epidemiological characteristics and related indicators of plague in Yulin City, Shaanxi Province, and to evaluate the risk of plague epidemic in the future and formulate scientific and reasonable prevention and control measures.Methods:The plague surveillance data of national (Dingbian County) and provincial (Yuyang District, Jingbian County, Hengshan District, Shenmu City, Fugu County) plague monitoring sites in Yulin City from 2011 to 2021 were collected through the China Disease Prevention and Control Information System Pestis Prevention and Control Management Information System, and the plague epidemic situation among humans and animals, the main host animals and their flea infection were analyzed by descriptive epidemiological methods. The expert consultation method and plague risk assessment tool V1.0 were used to assess the epidemic risk of the plague in Yulin City.Results:There was no human and animal plague epidemic in Yulin City from 2011 to 2021. In national monitoring site, the density of main host animal was 5.79/hm 2, ranging from 3.02/hm 2 to 9.08/hm 2,the dominant species was Mongolian gerbil, accounting for 98.21% (3 402/3 464); the capture rate of wild nocturnal rodents was 1.27% (350/27 600), ranging from 0.21% to 3.83%, the dominant species was Cricetulus barabensis, accounting for 44.86% (157/350); the flea infection rate of the rodent body was 16.91% (768/4 541), with a flea index of 0.40, the dominant flea species was the Nosopsyllus laeviceps kuzenkov, accounting for 66.54% (1 203/1 808). In provincial monitoring site, the density of main host animals was 0.49/hm 2, ranging from 0.31/hm 2 to 0.67/hm 2, the dominant species was Alashan ground squirrel, accounting for 63.61% (194/305); the capture rate of nocturnal rodents in the wild was 1.76% (560/31 795), ranging from 0.89% to 3.93%, the dominant species was Roborovski dwarf hamster, accounting for 26.61% (149/560); the capture rate of domestic rats was 2.37% (397/16 750), ranging from 1.48% to 3.10%, the rodents included Rattus norvegicus (47.36%, 188/397) and house mouse (52.64%, 209/397); the flea infection rate of the rat body was 13.26% (182/1 373), with a flea index of 0.40; the dominant flea species was Ophthalmopsylla jettmari, accounting for 45.23% (251/555). The 5 281 pathogenic culture samples and 2 110 serological test samples were all negative. The Pearson correlation analysis results showed that there was no correlation between rodent density and flea infection rate or flea index at national and provincial monitoring sites ( r = - 0.26, - 0.48, 0.09, 0.12, P > 0.05), while flea infection rate and flea index were positively correlated ( r = 0.67, 0.81, P < 0.05). In 2022, Yulin City, Shaanxi Province was not ruled out the possibility of human plague epidemic, and the risk of plague epidemic among animals was high. Conclusions:From 2011 to 2021, the density of the main host animals at the national and provincial monitoring sites in Yulin City has remained at a low level, and the flea index has increased. There is a risk of plague epidemic in Yulin City, so the monitoring work should be further strengthened, and emergency supplies and capacity reserves should be well prepared.

Objective:To construct a follow-up evaluation index system for "Diagnosis of Brucellosis" (WS 269-2019), and provide a reference basis for the next revision and improvement of the standard.Methods:The evaluation index system for "Diagnosis of Brucellosis" (WS 269-2019) was preliminarily established by consulting relevant references and materials. The experts in the field of diagnosis, treatment, prevention and control of brucellosis were selected, and two rounds of expert consultation were carried out in the form of questionnaires using the Delphi method. The necessity and availability of evaluation indicators were scored, and suggestions for modifying and adding indicators were put forward. Based on this, a standard follow-up evaluation index system was established. At the same time, a judgment matrix was constructed combined with the Saaty scale, and the analytic hierarchy process was used to calculate the weight of each index in the system.Results:After 2 rounds of expert ( n = 10) consultation, a standard follow-up evaluation index system for "Diagnosis of Brucellosis" (WS 269-2019) was constructed with 3 first-level indexes, 8 second-level indexes and 21 third-level indexes. The positive coefficients of experts in 2 rounds of questionnaires were both 100%; the coefficient of authority of experts was 0.82; the Kendall's coefficients of concordance of first-level, second-level and third-level indexes were 0.722, 0.260, and 0.181, respectively, with P < 0.05. Among the first-level indexes, the weight of standard quality evaluation was the highest (0.364), and the weight of standard implementation status was the lowest (0.278); among the second-level indexes, the combined weight of social benefits was the highest (0.186), and the combined weight of advanced nature was the lowest (0.043); among the third-level indexes, the combined weight of timely diagnosis rate was the highest (0.096), and the combined weight of consistency with technical data was the lowest (0.009). Conclusions:The constructed follow-up evaluation index system for "Diagnosis of Brucellosis" (WS 269-2019) is scientific and reliable, which evaluated qualitatively and quantitatively, reduces the defects of a single evaluation, and provides a basis for subsequent revision and improvement of the standard.

目的 了解《布鲁氏菌病诊断》(WS 269-2019)(简称标准)的宣贯、实施和使用情况以及使用过程中存在的问题,为标准的修订和完善提供参考.方法 采用分层抽样调查和国家布病监测防控工作系统公开广泛调查相结合的方法,对全国布病一、二、三类部分流行地区的各级疾病预防控制中心(简称疾控机构)和临床医疗机构中从事布病流行病学调查、实验室检验和临床诊治的卫生专业人员开展问卷调查和访谈.结果 参与问卷调查的省份(直辖市)有16个,共调查疾控机构和临床医疗机构763家,收回问卷1 479份,问卷有效率为100.00％,其中调查疾控机构261家,完成问卷调查530份;调查临床医疗机构502家,完成问卷调查949份.调查对象平均年龄为(40.29±9.62)岁,学历中本科及以上占56.19％,职称以中初级职称占比最高(占34.75％),专业以临床诊断治疗为主(占48.88％),专业年限以5年以下为主(占54.02％).1 479名调查对象中,标准知晓率为88.30％(1 306/1 479),其中疾控机构知晓率为92.83％(492/530),临床医疗机构知晓率为85.77％(814/949),两者差异具有统计学意义(x2=16.391,P＜0.001);布病相关实验室检验项目开展率为79.86％(1 043/1 306),且调查对象所在的省市级医疗机构布病相关实验室检验项目开展率最高,为88.79％(285/321),其次为县区级(87.79％,460/524)和乡镇级(64.64％,298/461)医疗机构,差异有统计学意义(X2=102.752,P＜0.001).1.35％(20/1 479)认为该标准与国家法律法规及其他相关标准、现行教材矛盾.通过问卷调查和电话回访共收集到关于布病检验、病例诊断和宣贯培训3个方面的意见和建议.结论 该标准是现阶段开展布病诊断工作的唯一指导性文件,建议进一步完善和修订该标准,加强该标准的宣贯和培训,提高临床医疗机构对该标准的使用和掌握,提升布病检测水平和特异性,从而有效推进布病防治工作的开展.

Human brucellosis (HB) is a seasonal and climate-affected infectious disease that is posing an increasing threat to public health and economy. However, most of the research on the seasonal relationships and impact of climatic factors on HB did not consider the secular trend and spatiotemporal effect related to the disease. We herein utilized long-term surveillance data on HB from 2008 to 2020 using sinusoidal models to explore detrended relationships between climatic factors and HB. In addition, we assessed the impact of such climatic factors on HB using a spatial panel data model combined with the spatiotemporal effect. HB peaked around mid-May. HB was significantly correlated with climatic factors with 1–5-month lag when the respective correlations reached the maximum across the different lag periods. Each 0.1 °C increase in temperature led to 0.5

Objective:To analyze the incidence of brucellosis and the genotypes of Brucella isolates or nucleic acids in Shaanxi Province, to get the epidemiological and molecular genetic characteristics, and to provide scientific basis for precise prevention and control of human brucellosis. Methods:Log into the Chinese Disease Control and Prevention Information System, collect the incidence data of human brucellosis of Shaanxi Province in 2020, and analyze the epidemiological characteristics. Bacteriology and PCR methods were used to identify the isolates or nucleic acids, and multiple locus variable-number tandem repeat analysis (MLVA) was used for molecular typing. BioNumerics (Version 7.6) software was used to analyze the results of MLVA.Results:In 2020, 1 086 cases of human brucellosis were reported in Shaanxi Province, the incidence rate was 2.80/100 000, involving 86 counties (districts), the epidemic peak was from March to September (865 cases), male-to-female ratio was 2.68 ∶ 1.00 (791 ∶ 295), 79.74% (866 cases) in the age group of 30 to 69 years old, and 83.43% (906 cases) of the cases were farmers. Biotype identification of 36 isolates showed that 4 isolates were mutant Brucella melitensis, 3 isolates were Brucella melitensis 1 and 29 isolates were Brucella melitensis 3. The 36 isolates and 7 nucleic acids were identified as Brucella by BCSP31-PCR and Brucella melitensis by AMOS-PCR. MLVA-16 genotyping, panel1 showed two genotypes: type 42 (1-5-3-13-2-2-3-2) and type 63 (1-5-3-13-2-3-3-2), panel2A showed 4-41-8 and panel2B showed high variability. Thirty-six isolates and 7 nucleic acids were divided into 33 genotypes, of which 27 genotypes were single isolates and 6 genotypes were shared. Conclusions:The situation of human brucellosis prevention and control in Shaanxi Province is grim. MLVA-16 is a mature genotyping method, which determines the existence of multiple genotypes of Brucella isolates or nucleic acids in Shaanxi Province, which can provide scientific information for precise prevention and control of human brucellosis, outbreak analysis and epidemiological traceability.

Objective:To understand the changes of brucellosis prevention and control knowledge awareness among breeders in Chunhua County, Xianyang City, Shaanxi Province before and after the publicity intervention.Methods:A multi-stage cluster sampling method was adopted to select 10 townships with more reported cases of human brucellosis in Chunhua County from January 2019 to June 2020, and each township was given priority to select the administrative village with the largest number of reported cases for investigation. At least 20 breeders aged 20 years old and over in each administrative village were selected, and if the number was insufficient, supplementary surveys would be conducted in other administrative villages with the larger number of breeders in the township. Questionnaire survey was conducted on all subjects, including general demographic characteristics, brucellosis prevention and control knowledge and related protective behaviors. After the baseline investigation, 6 months of brucellosis prevention and control knowledge publicity was carried out in the administrative villages included in the investigation, and the awareness rate of brucellosis prevention and control knowledge before and after the publicity intervention was compared to evaluate the effect of publicity intervention.Results:After the publicity intervention, a total of 240 breeders were investigated, and 176 people were aware of brucellosis prevention and control knowledge, with an overall awareness rate of 73.33% (176/240), which was significantly higher than that before the publicity intervention (57.50%, 115/200), and the difference was statistically significant (χ 2 = 12.21, P = 0.005). After the publicity intervention, the awareness rates of breeders on "can cattle and sheep transmit diseases to humans" and "do you know that cattle and sheep can only be purchased after passing the quarantine inspection" were relatively high, they were 95.83% (230/240) and 95.00% (228/240), respectively, and the differences were statistically significant (χ 2 = 50.04, 112.64, P < 0.001) compared with that before the publicity intervention [71.50% (143/200) and 51.00% (102/200)]. The awareness rate of breeders on "how brucellosis is transmitted from livestock to humans" was the lowest, it was 53.33% (128/240), which was not significantly different (χ 2 = 0.82, P = 0.370) from that before the publicity intervention (49.00%, 98/200). Conclusions:After the publicity intervention, the overall awareness rate of brucellosis prevention and control knowledge of breeders in Chunhua County has improved, but the awareness rate of some individual issues is still low. It is suggested to strengthen the pertinence of publicity and education.

DEAR EDITOR,Mongolian gerbils（Meriones unguiculatus） are small rodents belonging to the family Muridae and widely inhabit typical steppes and desert grasslands across northern China. Yet,few viruses in wild M. unguiculatus have been reported. Using meta-transcriptomic sequencing we identified two novel RNA viruses: an astrovirus, denoted Gerbil astrovirus（GeAstV）,

目的 通过CRISPR(间区规律短回文重复序列)对陕西省鼠疫菌进行基因分型,分析流行病学特征,为陕西省鼠疫防治工作提供科学依据.方法 提取分离自陕西省鼠疫疫源地的66株鼠疫菌核酸,利用针对鼠疫菌的3对CRISPR引物进行PCR扩增,对扩增产物进行测序及分析,确定CRISPR基因分型.结果 66株鼠疫菌在3个位点上共有12种spacer,其中 YPa3种、YPb5种、YPc4种,具体为 a1′、a2′、a3′、b1′、b2′、b29′、b1″、b2″、c1、c2、c3、c3′,基因簇为 Cb2′,基因型分为 1′和4′两种.结论 疫情发生年份不同,鼠疫菌CRISPR基因型不同,鼠疫疫情处置进行溯源应将生态分型与基因分型结合.

Objective:To analyze the epidemic characteristics of human brucellosis in Xianyang City, Shaanxi Province, to grasp the epidemic trend and provide scientific basis for further prevention and control of human brucellosis.Methods:Descriptive epidemiological methods were used to statistically analyze the incidence data and epidemic data of human brucellosis in Xianyang City, Shaanxi Province from 2011 to 2020 in the "Infectious Disease Surveillance System of China Disease Control and Prevention Information System".Results:A total of 864 human brucellosis cases had been reported in Xianyang City from 2011 to 2020, and there was no dead case. The annual incidence began to increase rapidly from 2014, the highest annual incidence in 2019 was 5.79/10 5. There were statistical differences between the incidence of different years (χ 2 = 900.40, P < 0.001). Human brucellosis cases in Xianyang City were mainly concentrated in dairy goat breeding counties, with a total of 571 cases reported, accounting for 66.09%. Cases were reported in all months of the year, and the peak incidence of human brucellosis was from April to August, accounting for 64.35% (556/864). The age of cases was mainly concentrated in the 40 - 69 years old group, accounting for 68.29% (590/864); the ratio of male to female was 2.40 ∶ 1.00 (610 ∶ 254). The occupation was mainly farmers, accounting for 83.45% (721/864). There had been an increase in the proportion of scattered children, students and preschool children. The total serological positive rate was 3.14% (283/9 009) in Xianyang City, and pathogenic culture showed variant strains. The median of interval between onset time and diagnosis time was 8 days. Conclusion:The prevalence of human brucellosis in Xianyang City, Shaanxi Province shows an overall upward trend, which needs to be paid more attention to and control efforts should be strengthened.

目的 分析2016-2020年陕西省榆林市布鲁氏菌病(简称布病)发病的流行特征和时空聚集性,为制订布病防控策略提供依据.方法 通过中国疾病预防控制信息系统收集2016-2020年陕西省榆林市布病发病数据,进行描述性流行病学分析,同时利用ArcGIS 10.8、GeoDa 1.6、SaTScan 9.4.1软件分别进行三维分析、空间 自相关分析和时空扫描分析.结果 2016-2020年陕西省榆林市共报告布病病例1 773例,年均发病率为10.40/10万.病例报告以5-8月为主,病例性别比为3.53 ∶ 1(1 382/391),年龄以45～64岁人群为主(占60.46％),职业以农民为主(占89.57％).三维趋势分析显示榆林市布病发病率呈现由北向南、由西向东逐渐升高.空间 自相关分析显示,2016-2020年榆林市布病发病率Moran's I值分别为0.478 0、0.444 0,0.289 0、0.322 0、0.260 3,局部Moran's I系数检验发现榆林市布病发病有2个"高-高"聚集县区和3个"低-低"聚集县区.时空扫描分析显示,2016-2020年榆林市布病发病扫描到1个一类时空聚集区和1个二类时空聚集区,聚集时间为2019年.其中一类聚集区(LRR=57.97,RR=2.49,P＜0.001)以米脂县为中心,半径为51.62 km,涉及5个县区.结论 2016-2020年榆林市布病呈现明显的时空聚集性,应结合布病发病流行高峰期、发病人群、时空聚集区、羊只存栏量等情况,采取分区域、有重点、人畜同步联防的布病防控策略.

目的 调查2021年陕西省陕南地区一起人间布鲁氏菌病(简称布病)暴发疫情的原因,为今后该地区布病疫情防控提供借鉴依据.方法 通过现场流行病学调查和实验室检测,对2021年7月份商洛市丹凤县龙驹寨鹿池社区一起布病暴发疫情进行传染源追踪调查和传染途径分析.结果 共发现5例确诊病例、6例隐性感染者和1例疑似病例,病例性别比为3 ∶1,发病到确诊时间间隔87～123 d,中位数为119 d,临床表现以发热为主;12例病例血清抗体滴度从1 ∶50(++)到1 ∶1 600(++)不等;病例感染途径与清理圈舍有关联(OR=6.4,95％CI:1.195～34.285);畜间检测结果显示53只羊和2只犬均为布病阳性.结论 该起布病暴发疫情的主要原因是未及时清理羊只粪便、未定期对圈舍和生活居住环境进行消毒,导致养殖户及其家人、雇工等相继感染布病,建议畜牧部门调整陕南地区人间布病重点地区的牲畜免疫政策,同时人畜间联合加强圈舍、生活居住等环境消毒及个人防护等养殖科学卫生知识的宣传教育.

目的 对陕西省1952-2019年以来保存的布鲁氏菌分离株进行MLVA分型研究,了解陕西省布鲁氏菌遗传变异情况,为制定预防控制策略提供依据.方法 基于MLVA技术对收集的121株布鲁氏菌分离株基因型进行研究,利用Bio Numerics 7.6软件进行聚类分析,计算辛普森指数.结果 基于MLVA-8分型,分为7种,即羊种菌5种(42、43、63、83及115型),猪种菌1种(6型)及牛种菌1种(38型),其中羊种42、43型占总数的91.74％;42型在全省10个市区均有分布;榆林、延安均有4种基因型,多样性较其他市区更丰富;基于MLVA-11,分为11种,基于MLVA-16对121株菌种进行聚类分析结果显示,所有菌株分为3个群,96个基因型,呈现基因型别的多样性,辛普森指数在0.000 ～0.800之间,Panel 1和Panel 2A多样性均明显低于Panel 2B.结论 MLVA技术可用于种属亲缘关系的确立、菌株遗传多样性分析以及分子流行病学溯源调查,陕西省布鲁氏菌MLVA分型显示高度基因多态性,提示陕西省布病流行呈零星和散发特征,因此,降低传染源在区域之间的频繁流动,是控制布病疫情发生的有效手段.

Dear Editor,Hepaciviruses, members of the family Flaviviridae, are enveloped viruses containing a single-stranded positive-sense RNA genome of approximately 8.9–10.5 kb in size（Simmonds et al., 2017）. To date, 15species（Hepacivirus A–N, and P） have been documented within the Hepacivirus genus that show distinct host ranges, including primates,bats, horses, donkeys, cows, and various rodents（Hartlage et al., 2016）.

Objective To understand the epidemiological characteristics and incidence trend of brucellosis in Shaanxi province from 2019 to 2020 and provide evidence for the targeted brucellosis prevention and control. Methods The incidence data of brucellosis cases and outbreaks in Shaanxi from 2019 to 2020 were collected for a descriptive epidemiological analysis to understand the population, area and time distributions of brucellosis cases in Shaanxi by using software SPSS25.0 and Arc GIS10.8. At the same time, the characteristics of outbreaks and risk of different infection routes were also analyzed. Results A total of 2 254 brucellosis cases were reported in Shaanxi from 2019 to 2020, with an annual incidence rate of 2.93/10 0 000. The cases were mainly reported from April to September, which were mainly distributed in Guanzhong and northern Shaanxi, and there was statistically significant difference in the annual incidence rate among Guanzhong, northern Shaanxi and southern Shaanxi (χ2=1338.771, P Conclusion It is necessary to adhere and improve the joint prevention and control mechanism, strengthen the quarantine of sick animal and improve people’s knowledge, attitude and practice of brucellosis prevention and control to prevent and control brucellosis in Shaanxi.

In this study, a total of 179,907 blood samples from populations with suspected Brucella spp. infections were collected between 2008 and 2020 and analyzed by the Rose Bengal plate test (RBPT) and serum agglutination test (SAT). Moreover, conventional biotyping, B. abortus-melitensis-ovis-suis polymerase chain reaction (AMOS-PCR), and multiple-locus variable-number tandem repeat analysis (MLVA) was applied to characterize the isolated strains. A total of 8103 (4.50%) samples were positive in RBPT, while 7705 (4.28%, 95% confidence interval (CI) 4.19-4.37) samples were positive in SAT. There was a significant difference in seroprevalence for human brucellosis over time, in different areas and different cities (districts) (χ2 = 2 = 32.23, 1984.14, and 3749.51, p < .05). The highest seropositivity (8.22% (4, 965/60393; 95% CI 8.00-8.44) was observed in Yulin City, which borders Inner Mongolia, Ningxia, and Gansu Province, China, regions that have a high incidence of human brucellosis. Moreover, 174 Brucella strains were obtained, including nine with B. melitensis bv. 1, 145 with B. melitensis bv. 3, and 20 with B. melitensis variants. After random selection, 132 B. melitensis were further genotyped using MLVA-16. The 132 strains were sorted into 100 MLVA-16 genotypes (GTs) (GT 1-100), 81 of which were single GTs represented by singular independent strains. The remaining 19 shared GTs involved 51 strains, and each GT included two to seven isolates from the Shaan northern and Guanzhong areas. These data indicated that although sporadic cases were a dominant epidemic characteristic of human brucellosis in this province, more than 38.6% (51/132) outbreaks were also found in the Shaan northern area and Guanzhong areas. The 47 shared MLVA-16 GTs were observed in strains (n = 71) from this study and strains (n = 337) from 19 other provinces of China. These data suggest that strains from the northern provinces are a potential source of human brucellosis cases in Shaanxi Province. It is urgent to strengthen the surveillance and control of the trade and transfer of infected sheep among regions.

目的 对陕西省分离的77株布鲁氏菌菌株进行遗传多态性分析,了解其遗传特征及进化关系.方法 应用多位点序列分型(Multiple locus sequence typing,MLST)技术,测定77株陕西省地区布鲁氏菌分离株的7个管家基因、1个外膜蛋白基因及1个基因间区的序列,确定各菌株序列型(STs),运用BioNumerics(Version 7.6)构建最小进化树,分析菌株间遗传进化关系.结果 74株分离株(47株羊种3型、10株羊种1型、7株羊种2型、10株羊种变异型)序列型为ST8型,2株分离株(牛种生物型)序列型为ST2,1株分离株(猪种1型)序列型为ST14型.结论 不同生物型布鲁氏菌的MLST分型结果稳定,羊种3型(ST8型)布鲁氏菌是陕西省主要流行菌株;MLST分型作为传统生物分型的技术补充,建立了陕西省布鲁氏菌基因分型数据库,对本省今后人间布病的防控具有科学指导意义.

目的 调查2020年陕西省泾阳县一起家庭布鲁氏菌病(布病)暴发疫情的原因,明确传染源和传播途径,为阻断疫情传播提供科学依据.方法 对报告病例开展布病流行病学调查,并对病例和牲畜进行布病检测和布鲁氏菌分离培养鉴定种型,对结果进行描述和分析.结果 共发现7例确诊病例和6例隐性感染者;确诊病例发病时间为3月18日至5月7日,临床表现以发热为主;经分析,病例发病与食用牛肉无关联(OR =0.48,95％ CI:0.08～2.85),与去过首发病例家有关(OR=141.00,95％CI:17.15～1159.28);13例病例、2只羊和2只公犬布鲁氏菌抗体检测阳性,血清抗体滴度从1∶100(++)到1∶800(++++)以上;从2例病例、2只羊和1只公犬血液中共分离到5株布鲁氏菌,均为羊种3型,MLVA-16基因型均为(1-5-3-13-2-2-3-2-4-41-8-6-4-3-4-5).结论 该起布病家庭暴发疫情的原因为公犬叼食了布病阳性羊只的流产物而感染布病,继而人通过与病犬直接接触以及接触被病犬污染的水等生活物质而发病.