2016——2017年苏州市主城区一起人间布病暴发疫情流行病学调查

目的 了解2016——2017年苏州市主城区一起人间布病高度散发疫情可能的感染来源及危险因素,为制定防控策略提供依据。方法 按病例和对照1:4配比开展病例对照研究,入户开展流行病学调查,收集基本情况、临床表现、可疑暴露史,对确诊病例血培养物进行分离纯化,菌株进行多位点可变数目串联重复序列分析。结果 调查到的33例病例中,与羊肉相关的暴露比例最高为97%,暴露方式主要为使用和直接接触,暴露地点主要在葑门横街市场。食用羊肉、直接接触生羊肉、去过售卖羊肉的市场和去过葑门横街均是危险因素。经多位点串联重复序列分析,收集到的17株菌可分为5个基因型,但病原菌间亲缘关系较近。结论 苏州市主城区疫情源头可能为外地输入苏州的布鲁氏病羊于苏州城区宰杀或直接输入带菌羊肉,葑门横街市场售卖的羊肉是可能的传染源之一。在本次疫情中,非职业人群感染布鲁氏菌的主要途径是食用和直接接触带菌羊肉,近距离吸入带菌生羊肉产生的气溶胶可能也是该次疫情的感染途径。

Epidemiological investigation of a human brucellosis outbreak in main urban area of Suzhou City from 2016 to 2017

To investigate the possible infection sources and risk factors for a highly sporadic epidemic of brucellosis among humans in the main urban area of Suzhou from 2016 to 2017, and to provide a basis for prevention and control strategies, a case-control study was carried out according to a 1:4 ratio of cases to controls. A household epidemiological investigation was conducted, and basic information, clinical manifestations and suspected exposure history were collected, blood cultures of confirmed cases were isolated and purified, and strains were analyzed by multi-locus variable number tandem repeat sequence. Among the 33 cases investigated, the highest proportion of exposure, related to mutton, was 97%. The main methods of exposure were use and direct contact, and the main place of exposure was the Fengmen Market. Consumption of mutton, direct contact with raw mutton, and travel to mutton markets and Frengmen Street were risk factors. The 17 strains could be divided into five genotypes by multiple locus tandem repeat analysis, but their genetic relationships were close. The source of the epidemic in the main urban area of Suzhou may be brucellosis infected sheep imported from other places to Suzhou and slaughtered in the urban area of Suzhou or direct imports of infected mutton. Lamb sold in the Fengmen Market is one of the possible sources of infection. In this outbreak, the main route of Brucella infection among non-occupationally exposed people was eating and direct contact with infected mutton, inhaling aerosols from infected raw mutton may also be a route of infection.