Division of Tuberculosis Elimination, Centers for Disease Control and Prevention, Atlanta, Georgia.
Division of Tuberculosis Elimination, Centers for Disease Control and Prevention, Atlanta, Georgia.
Am J Prev Med. 2021 Aug;61(2):201-208. doi: 10.1016/j.amepre.2021.02.006. Epub 2021 May 13.
In the U.S., universal genotyping of culture-confirmed tuberculosis cases facilitates cluster detection. Early recognition of the small clusters more likely to become outbreaks can help prioritize public health resources for immediate interventions.
This study used national surveillance data reported during 2009-2018 to describe incident clusters (≥3 tuberculosis cases with matching genotypes not previously reported in the same county); data were analyzed during 2020. Cox proportional hazards regression models were used to examine the patient characteristics associated with clusters doubling in size to ≥6 cases.
During 2009-2018, a total of 1,516 incident clusters (comprising 6,577 cases) occurred in 47 U.S. states; 231 clusters had ≥6 cases. Clusters of ≥6 cases disproportionately included patients who used substances, who had recently experienced homelessness, who were incarcerated, who were U.S. born, or who self-identified as being of American Indian or Alaska Native race or of Black race. A median of 54 months elapsed between the first and the third cases in clusters that remained at 3-5 cases compared with a median of 9.5 months in clusters that grew to ≥6 cases. The longer time between the first and third cases and the presence of ≥1 patient aged ≥65 years among the first 3 cases predicted a lower hazard for accumulating ≥6 cases.
Clusters accumulating ≥3 cases within a year should be prioritized for intervention. Effective response strategies should include plans for targeted outreach to U.S.-born individuals, incarcerated people, those experiencing homelessness, people using substances, and individuals self-identifying as being of American Indian or Alaska Native race or of Black race.
在美国，对经培养确证的结核病病例进行普遍基因分型有助于发现聚集性病例。及早识别更有可能发展为暴发的小聚集性病例有助于为立即干预措施优先分配公共卫生资源。
本研究使用了 2009 年至 2018 年报告的国家监测数据，描述了新发病例聚集性（≥3 例结核病例，其基因型与同一县以前报告的病例不匹配）；数据于 2020 年进行分析。采用 Cox 比例风险回归模型来研究与聚集性病例数量增加到≥6 例相关的患者特征。
2009 年至 2018 年，美国 47 个州共发生了 1516 起新发病例聚集性事件（涉及 6577 例病例）；231 个聚集性事件有≥6 例病例。聚集性病例中，使用物质、近期无家可归、被监禁、美国出生或自我认定为美国印第安人或阿拉斯加原住民或非裔美国人的患者比例过高。聚集性病例仍为 3-5 例时，从首例病例到第 3 例病例的中位时间间隔为 54 个月，而增长到≥6 例病例的中位时间间隔为 9.5 个月。在聚集性病例中，从首例病例到第 3 例病例的时间间隔较长，以及前 3 例病例中≥1 例患者年龄≥65 岁，这两个因素均预示着积累≥6 例病例的风险较低。
一年内聚集性病例≥3 例的情况应优先考虑干预。有效的应对策略应包括针对美国出生者、被监禁者、无家可归者、使用物质者以及自我认定为美国印第安人或阿拉斯加原住民或非裔美国人的个体进行有针对性的外展计划。
