Department of Respiratory Medicine, Institute for Lung Health, Glenfield Hospital, , Leicester, Leicestershire, UK.
Thorax. 2014 Apr;69(4):354-62. doi: 10.1136/thoraxjnl-2013-203805. Epub 2013 Nov 19.
Most UK tuberculosis (TB) cases occur in immigrants from high TB incidence areas, implicating reactivation of imported latent TB infection (LTBI). Strategies to identify and treat immigrant LTBI in primary care at the time of first registration (coded Flag-4) may be effective.
This was an 11-year retrospective cohort study to evaluate effectiveness of LTBI screening in recent immigrants to Leicestershire at their time of primary care registration. We examined the temporal relationship between dates of Flag-4 primary care registration (n=59 007) and foreign-born TB (FB-TB) cases (n=857), for immigrants arriving to the UK after 1999. TB diagnosed >6 months after registration was considered potentially preventable with screening. Primary outcomes were the potentially preventable proportion of FB-TB and the number needed to screen (NNS) of immigrants to identify one potentially preventable case, stratified by age and region of origin.
250 cases (29%) were potentially preventable in Flag-4-registered immigrants. Overall, 511 cases (60%) were potentially preventable among primary-care registered immigrants, implying a significant proportion without Flag-4 status. Prospective TB incidence (95% CI) after Flag-4 registration was 183 (163 to 205) cases/100 000 person-years, with a NNS (95% CI) of 145 (130 to 162). Targeted screening was most effective for 16-35 year olds from TB incidence regions 150-499/100 000 (NNS (95% CI)=65 (57 to 74), preventing 159 (18.7%) cases). Unpreventable TB risk increased with delayed primary care registration after UK entry (p<0.001) and was associated with HIV seropositivity (relative risk (95% CI)=1.89 (1.25 to 2.84), p=0.003).
LTBI screening at primary care registration offers an effective strategy for potentially identifying immigrants at high risk of developing TB.
大多数英国结核病（TB）病例发生在来自高结核病发病率地区的移民中，这表明潜伏性 TB 感染（LTBI）的再激活。在首次登记时（编码 Flag-4），在初级保健中识别和治疗移民 LTBI 的策略可能是有效的。
这是一项回顾性队列研究，对莱斯特郡的移民在首次登记时 LTBI 筛查的有效性进行了 11 年的评估。我们检查了 Flag-4 初级保健登记（n=59007）和外国出生结核病（FB-TB）病例（n=857）日期之间的时间关系，这些移民是在 1999 年后抵达英国的。登记后 6 个月以上诊断的 TB 被认为可以通过筛查预防。主要结局是潜在可预防的 FB-TB 比例和识别一个潜在可预防病例所需的筛查人数（NNS），按年龄和原籍地区分层。
在 Flag-4 登记的移民中，有 250 例（29%）病例是潜在可预防的。总体而言，在初级保健登记的移民中，有 511 例（60%）病例是潜在可预防的，这意味着有相当一部分人没有 Flag-4 状态。Flag-4 登记后前瞻性 TB 发病率（95%CI）为 183（163 至 205）例/100000 人年，NNS（95%CI）为 145（130 至 162）例。针对结核病发病率为 150-499/100000 的 16-35 岁年龄组的靶向筛查最为有效（NNS（95%CI）=65（57 至 74），可预防 159 例（18.7%）病例）。在英国入境后延迟初级保健登记（p<0.001）和 HIV 血清阳性（相对风险（95%CI）=1.89（1.25 至 2.84），p=0.003）与不可预防的 TB 风险增加相关。
在初级保健登记时进行 LTBI 筛查是一种有效的策略，可以有效地识别有患 TB 风险的移民。
