Chakhaia Tsira, Magee Matthew J, Kempker Russell R, Gegia Medea, Goginashvili Leila, Nanava Ucha, Blumberg Henry M
University Research Co., LLC. Branch in Georgia, USAID Georgia TB Prevention Project, Tbilisi, Georgia.
Division of Epidemiology and Biostatistics, School of Public Health, Georgia State University, Atlanta, Georgia, United States of America; Departments of Epidemiology and Global Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, United States of America.
PLoS One. 2014 Nov 7;9(11):e111773. doi: 10.1371/journal.pone.0111773. eCollection 2014.
The study was conducted at the National Center for Tuberculosis and Lung Diseases (NCTBLD) in Tbilisi, Georgia.
To assess the utility of contact investigation for tuberculosis (TB) case detection. We also assessed the prevalence and risk factors for active TB disease and latent TB infection (LTBI) among contacts of active pulmonary TB cases.
A retrospective cohort study was conducted among the contacts of active pulmonary TB cases registered in 2010-2011 at the NCTBLD in Tbilisi, Georgia. Contacts of active TB patients were investigated according to an "invitation model": they were referred to the NCTBLD by the index case; were queried about clinical symptoms suggestive of active TB disease; tuberculin skin testing and chest radiographs were performed. Demographic, laboratory, and clinical data of TB patients and their contacts were abstracted from existing records up to February 2013.
869 contacts of 396 index cases were enrolled in the study; a median of 2 contacts were referred per index case. Among the 869 contacts, 47 (5.4%) were found to have or developed active TB disease: 30 (63.8%) were diagnosed with TB during the baseline period (co-prevalent cases) and 17 (36.2%) developed active TB disease during the follow-up period (mean follow up of 21 months) (incident TB cases). The incidence rate of active TB disease among contacts was 1126.0 per 100,000 person years (95% CI 655.7-1802.0 per 100,000 person-years). Among the 402 contacts who had a tuberculin skin test (TST) performed, 52.7% (95% CI 47.7-57.7%) had LTBI.
A high prevalence of LTBI and active TB disease was found among the contacts of TB cases in Tbilisi, Georgia. Our findings demonstrated that an "invitation" model of contact investigation was an effective method of case detection. Therefore, contact investigation should be scaled up in Georgia.
本研究在格鲁吉亚第比利斯的国家结核病和肺部疾病中心（NCTBLD）开展。
评估接触者调查在结核病（TB）病例发现中的作用。我们还评估了活动性肺结核病例接触者中活动性结核病和潜伏性结核感染（LTBI）的患病率及危险因素。
对2010年至2011年在格鲁吉亚第比利斯NCTBLD登记的活动性肺结核病例的接触者进行了一项回顾性队列研究。活动性肺结核患者的接触者按照“邀请模式”进行调查：他们由索引病例转诊至NCTBLD；询问是否有提示活动性结核病的临床症状；进行结核菌素皮肤试验和胸部X光检查。截至2013年2月，从现有记录中提取了结核病患者及其接触者的人口统计学、实验室和临床数据。
396例索引病例的869名接触者纳入研究；每个索引病例转诊的接触者中位数为2名。在869名接触者中，47名（5.4%）被发现患有或发生了活动性结核病：30名（63.8%）在基线期被诊断为结核病（共患病病例），17名（36.2%）在随访期（平均随访21个月）发生了活动性结核病（新发结核病病例）。接触者中活动性结核病的发病率为每10万人年1126.0例（95%可信区间为每10万人年655.7 - 1802.0例）。在402名进行了结核菌素皮肤试验（TST）的接触者中，52.7%（95%可信区间47.7 - 57.7%）患有LTBI。
在格鲁吉亚第比利斯，结核病病例的接触者中LTBI和活动性结核病的患病率较高。我们的研究结果表明，接触者调查的“邀请”模式是一种有效的病例发现方法。因此，格鲁吉亚应扩大接触者调查的规模。
