Department of Respiratory Medicine, Institute for Lung Health, Glenfield Hospital, Leicester, UK.
Thorax. 2013 Mar;68(3):240-6. doi: 10.1136/thoraxjnl-2011-200956. Epub 2012 Sep 6.
The efffectiveness of tuberculosis (TB) contact screening programmes using interferon γ release assays remains uncertain as prospective contact TB risk is not well characterised.
To quantify 2-year TB risk and evaluate screening performance with single-step QuantiFERON TB Gold-In Tube (QFT) in adult contacts. To compare TB risk between QFT tested subgroups stratified by exposure type (smear positive pulmonary (SP) versus non-smear positive (NSP) TB) and age (younger (16-35 years) versus older (≥36 years)).
Screening involved QFT testing in older contacts of SP and all younger contacts, 8-12 weeks after index notification. Chemoprevention (3RH) was offered to QFT positive (+) younger adults. TB risk was determined in a prospective cohort study.
43 TB events occurred in 1769 adult contacts observed for median 717 days (2-year rate (95% CI)=2·5% (1.7 to 3.2)). Index-contact strain matching was demonstrable for 18 of 22 (82%) paired samples. No contacts (0/98) receiving 3RH developed TB. 215 of 817 appropriately tested adults (26.3%) were QFT+. 14 of 112 untreated QFT+ adults developed TB (2-year rate (95% CI)=13·4% (7.7 to 21.1)). The model required 35 contacts screened with QFT to identify one contact developing TB at 2 years. TB rates were comparable in QFT+ contacts of SP and NSP (rate ratio (RR)=0.98, p=0·962). For QFT+ older contacts, the disease rate was lower (8.9% (3.3 to 19.1)) and similar to the overall group rate (RR=1.4, p=0.503).
QFT based single-step contact screening is effective in young adults.
使用干扰素γ释放试验的结核病（TB）接触筛查计划的有效性尚不确定，因为前瞻性接触 TB 风险未得到很好的描述。
量化 2 年 TB 风险，并评估成人接触者中一步法 QuantiFERON TB Gold-In Tube（QFT）的筛查性能。比较 QFT 测试亚组之间的 TB 风险，这些亚组按暴露类型（涂片阳性肺（SP）与非涂片阳性（NSP）TB）和年龄（年轻（16-35 岁）与年长（≥36 岁））分层。
筛查包括对 SP 索引通知后 8-12 周时的年长接触者和所有年轻接触者进行 QFT 检测。QFT 阳性（+）年轻成年人接受 3RH 化学预防。TB 风险在前瞻性队列研究中确定。
在 1769 名成年接触者中观察到中位 717 天（2 年发生率（95%CI）=2.5%（1.7 至 3.2））发生了 43 例 TB 事件。18 对 22 对配对样本中可证明索引接触株匹配。未接受 3RH 的 98 名接触者中无 1 人发生 TB。在 817 名接受适当测试的成年人中，215 人（26.3%）为 QFT+。14 名未经治疗的 QFT+成年人发生了 TB（2 年发生率（95%CI）=13.4%（7.7 至 21.1））。该模型需要筛查 35 名 QFT 接触者，才能在 2 年内发现 1 名接触者发生 TB。QFT+SP 和 NSP 接触者的 TB 发生率相当（发病率比（RR）=0.98，p=0.962）。对于 QFT+年长接触者，疾病发生率较低（8.9%（3.3 至 19.1）），与总体组率相似（RR=1.4，p=0.503）。
基于 QFT 的一步法接触筛查在年轻成年人中有效。
