Noertjojo K, Tam C M, Chan S L, Tan J, Chan-Yeung M
Department of Medicine, The University of Hong Kong.
Int J Tuberc Lung Dis. 2002 Jan;6(1):19-24.
The tuberculosis programme of the Hong Kong Government Tuberculosis and Chest Service.
To determine the outcome of examination of household contacts in Hong Kong.
A retrospective cohort study of all household contacts of 970 randomly selected index cases from a total of 5757 registered for treatment with the Chest Service.
Of 2678 household contacts (three/index case) identified, 90% were examined; 41 active cases were found, at a rate of 1720/100000 (95%CI 1238-2329). The rate was highest among two extremes of age, 3604/100000 (95%CI 990-3615) in children < or = 5 years and 3347/100000 (95%CI 1456-6489) in those >60 years of age. Contacts of index cases whose sputum smear and culture were positive had the highest rate of disease, 2904/100000 (95%CI 1669-4673); but contacts with negative bacteriology also had a high rate of 1478/100000 (95%CI 678-2789). Active cases identified through contact tracing could be source cases rather than secondary cases. Eight per cent of children aged < or = 5 years had positive tuberculin reactions; as BCG vaccination is given to all newborns, with 99% coverage in Hong Kong in the past 30 years, it was difficult to estimate the rate of infection in these children.
In Hong Kong, an area with an intermediate burden of tuberculosis, contact investigation is a very useful procedure for active case finding.
香港政府胸肺科的结核病防治计划。
确定香港家庭接触者的检查结果。
对胸肺科登记治疗的5757例患者中随机抽取的970例索引病例的所有家庭接触者进行回顾性队列研究。
在确定的2678名家庭接触者（平均每户3人）中，90%接受了检查；发现41例活动性病例，发病率为1720/10万（95%可信区间1238 - 2329）。发病率在两个年龄极端人群中最高，5岁及以下儿童为3604/10万（95%可信区间990 - 3615），60岁以上人群为3347/10万（95%可信区间1456 - 6489）。痰涂片和培养阳性的索引病例的接触者疾病发病率最高，为2904/10万（95%可信区间1669 - 4673）；但细菌学检查阴性的接触者发病率也较高，为1478/10万（95%可信区间678 - 2789）。通过接触者追踪发现的活动性病例可能是传染源而非继发病例。5岁及以下儿童中有8%结核菌素反应呈阳性；由于香港所有新生儿均接种卡介苗，过去30年接种覆盖率达99%，因此难以估计这些儿童的感染率。
在结核病负担中等的香港地区，接触者调查是主动发现病例的非常有用的方法。
