Division of Occupational Medicine, School of Public Health and Family Medicine, University of Cape Town, Cape Town, South Africa.
Department of Environmental and Occupational Studies, Faculty of Applied Sciences, Cape Peninsula University of Technology, Cape Town, South Africa.
BMC Infect Dis. 2019 Feb 8;19(1):131. doi: 10.1186/s12879-019-3745-5.
The tuberculin skin test (TST) and interferon-gamma-release-assays (IGRAs) are utilized in screening programmes for presumed latent tuberculosis infection (LTBI) in health care workers (HCWs). However, inter-test comparison yields high rates of discordance, which is poorly understood. The aim of the study was therefore to identify factors associated with discordance amongst HCWs in a TB and HIV endemic setting.
505 HCWs were screened for LTBI in South Africa using the TST and two IGRA assays (QuantiFERON-TB-Gold-In-Tube (QFT-GIT) and TSPOT.TB). Factors associated with discordance were analyzed using a multinomial logistic regression model.
TST-IGRA discordance was negatively associated with longer duration of employment for both TSPOT.TB (OR = 0.92; 95% confidence interval (CI) 0.85-0.99) and QFT-GIT (OR = 0.90; 95% CI 0.84-0.96). Marked test discordance occurred in HIV-infected individuals who were more likely to have TSPOT.TB + ve / TST-ve discordance (OR 4.44; 95% CI 1.14-17.27) or TSPOT.TB + ve / QFT-GIT-ve test discordance (OR 5.72; 95% CI 1.95-16.78). Those engaged in home care were less likely to have QFT-GIT + ve/TSPOT.TB -ve / discordance (OR 0.32; 95% CI 0.10-0.95).
The marked TST-IGRA and IGRA-IGRA discordance in HIV-infected individuals suggest greater sensitivity of TSPOT.TB in immunocompromised persons or potential greater reactivity of TSPOT.TB in this population.
结核菌素皮肤试验（TST）和干扰素-γ释放检测（IGRAs）用于筛查卫生保健工作者（HCWs）中疑似潜伏性结核感染（LTBI）的筛查方案。然而，测试间的比较结果显示出高度的不一致，这一点理解得很差。因此，本研究的目的是在结核病和艾滋病流行地区确定与 HCWs 之间不一致相关的因素。
在南非，使用 TST 和两种 IGRA 检测（QuantiFERON-TB-Gold-In-Tube（QFT-GIT）和 TSPOT.TB）对 505 名 HCWs 进行 LTBI 筛查。使用多项逻辑回归模型分析与不一致相关的因素。
TST-IGRA 不一致与 TSPOT.TB（OR=0.92；95%置信区间（CI）0.85-0.99）和 QFT-GIT（OR=0.90；95%CI 0.84-0.96）的就业时间更长呈负相关。在 HIV 感染者中，明显的测试不一致更可能发生 TSPOT.TB 阳性/TST 阴性（OR 4.44；95%CI 1.14-17.27）或 TSPOT.TB 阳性/QFT-GIT 阴性测试不一致（OR 5.72；95%CI 1.95-16.78）。从事家庭护理的人更不可能出现 QFT-GIT 阳性/TSPOT.TB 阴性/不一致（OR 0.32；95%CI 0.10-0.95）。
在 HIV 感染者中，TST-IGRA 和 IGRA-IGRA 之间的明显不一致表明 TSPOT.TB 在免疫功能低下者中的敏感性更高，或者在该人群中 TSPOT.TB 的反应性可能更高。
