2020年陕西省一起布鲁氏菌病暴发疫情的调查分析

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:17.15~1 159.28);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。

Epidemiological investigation of a brucellosis outbreak in Shaanxi Province in 2020

The study examined the case of a familial brucellosis outbreak in Shaanxi Province in 2020. After investigation, a total of seven cases and six cases of latent infection were found, which had a relationship between seven cases and two latent infection cases. The blood antibody titer of Brucella, determined through SAT tests, ranged from 1∶100 (++) to 1∶800 (++++) or more. A total of seven cases were found from March 18th to May 7th in 2020, and the main clinical symptom was fever. According to our analysis, beef consumption was not the reason for brucellosis (OR=0.48), and the brucellosis infection correlated with visiting the home of the first case (OR=141.00). Five Brucella strains were isolated from the blood of two cases, two sheep and one male dog, and all strains were B. melitensis type 3. The five Brucella strain gene types were exactly the same as those determined through multiple locus variable-number tandem-repeat analysis: 1-5-3-13-2-2-3-2-4-41-8-6-4-3-4-5. On the basis of our epidemiological investigation and laboratory results, we believe that the family brucellosis outbreak occurred because the male dog was infected with brucellosis through eating the blood products of brucellosis-positive sheep; subsequently, nine families became infected through direct contact with the sick dog, respiratory tract, water polluted by sick dogs and other living environment goods.