Muliyil J, Nelson K E, Diamond E L
Community Health Department, Christian Medical College, Vellore, South India.
Int J Lepr Other Mycobact Dis. 1991 Jun;59(2):229-36.
The effect of BCG on the risk of leprosy was measured using a case-control design in an area endemic for the disease. In this study, 397 newly diagnosed cases and 669 controls matched for age, sex and locality were selected from a defined population. Information on exposure to BCG, contact with another case of leprosy, and relevant socioeconomic variables were obtained from the subjects. Having infectious (multibacillary) and noninfectious (paucibacillary) contacts in the household increased the risk of disease 11.7 times (p less than 0.001) and 2.7 times (p less than 0.001), respectively. Overall, the protection offered by BCG was not significant (odds ratio = 0.8; p = 0.17). However, BCG appeared to increase the risk for indeterminate leprosy (adjusted odds ratio = 2.7; p = 0.09) while protecting against borderline disease (adjusted odds ratio = 0.39; p = 0.03). It is possible that BCG causes a shift in the overall cell-mediated immune response, thus increasing the risk for milder and transient forms of leprosy while protecting against more serious forms. These findings may have important implications for the design and interpretation of vaccine trials. Namely, trials should be designed to measure the protective efficacy of vaccines against the more serious forms of leprosy, which have the greatest public health significance.
在麻风病流行地区，采用病例对照设计来衡量卡介苗对麻风病发病风险的影响。在本研究中，从特定人群中选取了397例新诊断病例和669例年龄、性别及居住地相匹配的对照。从研究对象处获取了关于卡介苗接种情况、与其他麻风病病例接触情况以及相关社会经济变量的信息。家中有传染性（多菌型）和非传染性（少菌型）接触者分别使发病风险增加了11.7倍（p<0.001）和2.7倍（p<0.001）。总体而言，卡介苗提供的保护作用不显著（优势比=0.8；p=0.17）。然而，卡介苗似乎增加了未定类麻风的发病风险（调整后优势比=2.7；p=0.09），同时对界线类疾病有预防作用（调整后优势比=0.39；p=0.03）。卡介苗可能会导致整体细胞介导免疫反应发生转变，从而增加轻度和短暂性麻风病的发病风险，同时预防更严重的麻风病形式。这些发现可能对疫苗试验的设计和解读具有重要意义。也就是说，试验应设计用于衡量疫苗对具有最大公共卫生意义的更严重麻风病形式的保护效力。
