Corbett Caroline, Kulzhabaeva Aizat, Toichkina Tatjana, Kalmambetova Gulmira, Ahmedov Sevim, Antonenka Uladzimir, Iskakova Altyn, Kosimova Dilorom, Migunov Dasha, Myrzaliev Bakyt, Sahalchyk Evgeni, Umetalieva Nagira, Vogel Monica, Kadyrov Abdylat, Hoffmann Harald
Departments SYNLAB Gauting & IML red GmbH, WHO - Supranational Tuberculosis Reference Laboratory Munich-Gauting, Institute of Microbiology and Laboratory Medicine, Robert-Koch-Allee 2, D-82131, Gauting, Germany.
fhi360; Defeat-TB program, Bishkek, Kyrgyz Republic.
BMC Infect Dis. 2020 Oct 12;20(1):746. doi: 10.1186/s12879-020-05465-x.
Effective active case finding (ACF) activities are essential for early identification of new cases of active tuberculosis (TB) and latent TB infection (LTBI). Accurate diagnostics as well as the ability to identify contacts at high risk of infection are essential for ACF, and have not been systematically reported from Central Asia. The objective was to implement a pilot ACF program to determine the prevalence and risk factors for LTBI and active TB among contacts of individuals with TB in Kyrgyz Republic using Quantiferon-TB Gold plus (QuantiFERON).
An enhanced ACF project in the Kyrgyz Republic was implemented in which close and household (home) contacts of TB patients from the Issyk-Kul Oblast TB Center were visited at home. QuantiFERON and the tuberculin skin test (TST) alongside clinical and bacteriological examination were used to identify LTBI and active TB cases among contacts. The association for QuantiFERON positivity and risk factors were analysed and compared to TST results.
Implementation of ACF with QuantiFERON involved close collaboration with the national sanitary and epidemiological services (SES) and laboratories in the Kyrgyz Republic. From 67 index cases, 296 contacts were enrolled of whom 253 had QuantiFERON or TST results; of those 103 contacts had LTBI (positive TST or IGRA), and four (1.4%) active TB cases were detected. Index case smear microscopy (OR 1.76) and high household density (OR 1.97) were significant risk factors for QuantiFERON positivity for all contacts. When stratified by age, association with smear positivity disappeared for children below 15 years. TST was not associated with any risk factor.
This is the first time that ACF activities have been reported for Central Asia, and provide insight for implementation of effective ACF in the region. These ACF activities using QuantiFERON led to increase in the detection of LTBI and active cases, prior to patients seeking treatment. Household density should be taken into consideration as an important risk factor for the stratification of future ACF activities.
有效的主动病例发现（ACF）活动对于早期识别活动性肺结核（TB）新病例和潜伏性结核感染（LTBI）至关重要。准确的诊断以及识别高感染风险接触者的能力对于ACF至关重要，而中亚地区尚未有系统的报告。目的是在吉尔吉斯共和国实施一项试点ACF计划，使用结核感染T细胞检测金标法（QuantiFERON）来确定结核病患者接触者中LTBI和活动性结核病的患病率及危险因素。
在吉尔吉斯共和国实施了一个强化的ACF项目，对伊塞克湖州结核病中心结核病患者的密切接触者和家庭（居家）接触者进行家访。使用结核感染T细胞检测、结核菌素皮肤试验（TST）以及临床和细菌学检查来识别接触者中的LTBI和活动性结核病病例。分析结核感染T细胞检测阳性与危险因素之间的关联，并与TST结果进行比较。
使用结核感染T细胞检测实施ACF需要与吉尔吉斯共和国的国家卫生和流行病学服务机构（SES）及实验室密切合作。从67例索引病例中，纳入了296名接触者，其中253名接触者有结核感染T细胞检测或TST结果；在这些接触者中，103名有LTBI（TST或干扰素释放试验阳性），并检测到4例（1.4%）活动性结核病病例。索引病例涂片显微镜检查（比值比1.76）和高家庭密度（比值比1.97）是所有接触者结核感染T细胞检测阳性的重要危险因素。按年龄分层时，15岁以下儿童与涂片阳性的关联消失。TST与任何危险因素均无关联。
这是中亚地区首次报告ACF活动，并为该地区实施有效的ACF提供了见解。这些使用结核感染T细胞检测的ACF活动导致在患者寻求治疗之前，LTBI和活动性病例的检测有所增加。家庭密度应被视为未来ACF活动分层的一个重要危险因素。
