结核分枝杆菌感染检测两步法在学校结核病筛查中的应用价值

Application value of two-step detection of Mycobacterium tuberculosis infection screening in schools

目的:初步评估结核菌素皮肤试验(TST)联合γ-干扰素释放试验(IGRA)(简称“两步法”)检测在学生健康体检中筛查结核分枝杆菌(Mycobacterium tuberculosis,MTB)感染和活动性肺结核的应用价值。方法:采用横断面研究的方法,选取2017-2021年广东省74358名学生作为研究对象,其中50701(68.18%)名完成了胸部X线摄片(简称“胸片”)筛查,74148名(99.72%)完成了TST筛查;9702(13.08%)名TST检测阳性者进一步完成了IGRA检测。最后对胸片异常、TST和IGRA检测“双阳者”完善肺结核相关检查。结果:以IGRA检测结果为参照标准,分别以TST检测硬结平均直径为5、10和15 mm为阳性临界值,TST与IGRA检测MTB感染的一致率分别为15.97%(1549/9702)、26.63%(2584/9702)、81.11%(7869/9702),Kappa值分别为0.014、0.014和0.112。TST检测MTB感染率[11.67%(8652/74148)]明显高于两步法[1.02%(759/74148)],差异有统计学意义(χ^(2)=7068.423,P<0.001)。对TST中阳和强阳者完善结核病相关检查后的肺结核检出率[0.29%(15/5219)]明显低于对“双阳者”的检出率[1.84%(14/759)],差异有统计学意义(χ^(2)=30.133,P<0.001)。结论:TST和IGRA检测MTB感染的一致性较差,“两步法”可明显提高MTB感染的精准性和肺结核患者筛查效率。

Objective:To evaluate the application value of tuberculin skin test(TST)combined with interferon-gamma release assays(IGRA)(shorter form“two-step”)screening Mycobacterium tuberculosis(MTB)infection and active tuberculosis in students’physical examination.Methods:A cross-sectional study was conducted in 74358 students in Guangdong during 2017-2021,50701(68.18%)were treated with chest X-ray and 74148(99.72%)were tested with TST.And then,9702(13.08%)students positive in TST test received IGRA test(two-step approach).Finally,the students with abnormal chest X-ray and those who were positive in TST and IGRA tests(double positive)should be further examined to clarify the diagnosis of pulmonary tuberculosis.Results:Using the IGRA test results as the reference standard,taking the mean diameter of induration detected by TST of 5,10 and 15 mm as the positive threshold,the consistency rates of MTB infection detected by TST and IGRA were 15.97%(1549/9702),26.63%(2584/9702)and 81.11%(7869/9702),respectively,with the Kappa values of 0.014,0.014 and 0.112,respectively.The rate of MTB infection detected by TST was significantly higher than that of the two-step method(11.67%(8652/74148)vs.1.02%(759/74148),χ^(2)=7068.423,P<0.001).The detection rate of pulmonary tuberculosis among students with moderate and strongly positive TST was significantly lower than that among students with double positive(0.29%(15/5219)vs.1.84%(14/759),χ^(2)=30.133,P<0.001).Conclusion:The consistency of detecting MTB infection by TST and IGRA is poor.The“two-step method”can significantly improve the detection rate of MTB infection and the screening efficiency of pulmonary tuberculosis in schools.