Department of Clinical Science, Faculty of Medicine, University of Bergen, Bergen, Norway.
Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark.
BMC Infect Dis. 2020 Jan 31;20(1):96. doi: 10.1186/s12879-020-4800-y.
The goal of tuberculosis elimination put forward in the End TB Strategy prioritizes diagnosis and treatment of incipient and subclinical TB, recently defined by key stakeholders as "asymptomatic, early pre-clinical disease during which pathology evolves". Regarded as indicative of a high risk of TB progression, considerable efforts have been made to identify these cases through exploration of biomarkers. The present study aimed to evaluate simple scoring systems for TB exposure as screening tools for subclinical TB, the only identifiable of the incipient and subclinical disease states, in a contact investigation (CI) setting of low HIV-prevalence.
Nested within a large prospective study in household contacts (HHCs) of smear positive pulmonary TB cases in South-India conducted 2010-2012, we assessed 1) the association between the Tuberculosis Contact Score (TCS) and the Infectivity Score, with established tools for Mycobacterium tuberculosis (Mtb) infection, corrected for established TB risk factors, and 2) the capability of the TB exposure scores to identify subclinical TB defined by Mtb-culture positivity in sputum or gastric aspirate (subjects < 5 years) specimen.
Of 525 HHCs, 29 were Mtb-culture positive and 96.6% of these asymptomatic. The TCS and the Infectivity Score associated with positive Tuberculin Skin Test and QuantiFeron TB-Gold In-tube assay (QFT) results in multivariate analyses (TCS: OR 1.16, 95% CI: 1.01, 1.33; OR 1.33 95% CI: 1.16, 1.51. Infectivity Score: OR 1.39, 95% CI: 1.10, 1.76; OR 1.41 95% CI: 1.16, 1.71). The Infectivity Score showed a moderate capability to identify subclinical TB (AUC of 0.61, 95% CI: 0.52, 0.70).
Although our results did not identify an easily applicable screening tool for subclinical TB, the present study indicates that focusing on TB-related symptoms in CI settings may be of limited value for early identification of HHCs with high risk for TB progression.
在终止结核病策略中提出的消除结核病目标优先考虑对初期和亚临床结核病的诊断和治疗，最近由主要利益攸关方定义为“无症状、临床前期疾病，在此期间病理学演变”。鉴于这是结核病进展的高风险的指标，已经做出了相当大的努力通过探索生物标志物来识别这些病例。本研究旨在评估用于结核暴露的简单评分系统作为筛查工具，用于在低 HIV 流行率的接触者调查（CI）环境中识别唯一可识别的初期和亚临床疾病状态的亚临床结核病。
在 2010-2012 年期间在印度南部进行的痰涂片阳性肺结核病例的家庭接触者（HHC）的大型前瞻性研究中进行嵌套研究，我们评估了 1）结核接触评分（TCS）与感染评分之间的关系，以及与已建立的结核分枝杆菌（Mtb）感染工具的关系，已建立的结核风险因素校正，以及 2）TB 暴露评分识别痰液或胃液抽吸物（<5 岁）标本中 Mtb 培养阳性定义的亚临床 TB 的能力。
在 525 名 HHC 中，有 29 名 Mtb 培养阳性，其中 96.6%为无症状。在多变量分析中，TCS 和感染评分与结核菌素皮肤试验和 QuantiFeron TB-Gold In-tube 检测（QFT）结果呈正相关（TCS：OR 1.16，95%CI：1.01，1.33；OR 1.33 95%CI：1.16，1.51.感染评分：OR 1.39，95%CI：1.10，1.76；OR 1.41 95%CI：1.16，1.71）。感染评分对识别亚临床 TB 具有中等能力（AUC 为 0.61，95%CI：0.52，0.70）。
尽管我们的结果没有确定用于亚临床结核病的易于应用的筛查工具，但本研究表明，在 CI 环境中关注与结核病相关的症状可能对早期识别具有较高结核病进展风险的 HHC 价值有限。
