McElnay Caroline, Thornley Craig, Armstrong Rob
Hawke's Bay District Health Board, Public Health Unit, Napier, New Zealand.
N Z Med J. 2004 Aug 20;117(1200):U1019.
To describe a community and workplace outbreak of tuberculosis in Hawke's Bay in 2002.
Contact tracing and case definitions used in this study followed New Zealand guidelines for tuberculosis control. DNA fingerprinting of Mycobacterium tuberculosis isolates was performed by restriction fragment length polymorphism (RFLP).
19 new cases of active tuberculosis disease (TBD) and 42 cases of latent tuberculosis infection (LTBI) were diagnosed. 55 family and close associates of the index case were investigated, of whom 9 (16.4%) had TBD disease and 11 (20.0%) had LTBI. 139 co-workers on the same work shift were investigated of whom 8 (5.8%) had TBD and 27 (19.4%) had LTBI. DNA typing of Mycobacterium isolates (from 4 TBD cases) confirmed that this was an outbreak of 'Rangipo'-strain TB.
High infection rates were observed among family, close associates, and workplace contacts. Several factors may have contributed to this high infection rate--ie, delays in presentation and contact tracing, the use of positive pressure ventilation and re-circulated unfiltered air, and virulence of this strain of Mycobacterium tuberculosis. Inadequate adherence to TBD treatment precipitated this outbreak and reinforces the recommendation that TBD cases (in whom risk factors for non-adherence are present) should receive directly observed therapy (DOT) or at least by close supervision. Further research into strain characteristics is required in order to determine if the Rangipo-strain of TB is truly more virulent and if contact tracing or treatment regimes need to be modified accordingly.
描述2002年霍克湾地区社区和工作场所的结核病暴发情况。
本研究中采用的接触者追踪和病例定义遵循新西兰结核病控制指南。通过限制性片段长度多态性（RFLP）对结核分枝杆菌分离株进行DNA指纹分析。
确诊了19例活动性结核病（TBD）新病例和42例潜伏性结核感染（LTBI）病例。对首例病例的55名家庭成员和密切接触者进行了调查，其中9人（16.4%）患有TBD，11人（20.0%）患有LTBI。对同一工作班次的139名同事进行了调查，其中8人（5.8%）患有TBD，27人（19.4%）患有LTBI。对结核分枝杆菌分离株（来自4例TBD病例）的DNA分型证实这是一次“兰伊波”菌株结核病的暴发。
在家庭成员、密切接触者和工作场所接触者中观察到高感染率。有几个因素可能导致了这种高感染率，即就诊和接触者追踪的延迟、使用正压通风和未经过滤的再循环空气，以及这种结核分枝杆菌菌株的毒力。对TBD治疗的依从性不足引发了此次暴发，并强化了以下建议：对于存在不依从风险因素的TBD病例，应接受直接观察治疗（DOT）或至少接受密切监督。需要对菌株特征进行进一步研究，以确定“兰伊波”菌株结核病是否真的更具毒力，以及接触者追踪或治疗方案是否需要相应修改。
