结核病症状筛查在四川省布拖县HIV感染/AIDS患者中发现结核病患者的价值

目的 探讨结核病症状筛查在HIV感染/AIDS患者中诊断活动性结核病的作用,为基层医生在HIV感染/AIDS患者中诊断结核病提供参考。方法 选取四川省凉山彝族自治州布拖县“两乡一镇”现场,对688例HIV感染/AIDS患者采用多项筛查的方法进行结核病筛查,其中“结核病症状筛查”共计发出了688份结核病可疑症状筛查问卷,回收628份,有效问卷623份。问卷调查表的主要内容包括:(1)咳嗽、咳痰持续2周;(2)反复咳出带血的痰;(3)反复发热持续2周以上;(4)夜间经常出汗;(5)无法解释的体质量明显下降;(6)经常容易疲劳或呼吸短促;(7)淋巴结肿大。出现(1)~(7)中1个或多个症状为结核病症状筛查阳性。专家组根据623例受检者的可疑症状问卷筛查、痰涂片显微镜检查、胸部X线摄影、痰培养、结核菌素试验和结核感染T淋巴细胞斑点试验(T-SPOT.TB)等检查结果综合判断,以确诊其中的活动性结核病。并以专家组诊断结果作为参考标准,计算结核病症状筛查在诊断活动性结核病的敏感度、特异度、阳性预测值、阴性预测值、约登指数、Kappa值,评价结核病症状筛查在HIV感染/AIDS患者中筛查结核病的应用价值。结果 现场结核病症状筛查中,结核病症状阳性率为66.29%(413/623),专家组共计确诊113例活动性结核病患者,以此作为参考标准,计算结核病症状筛查活动性结核病的敏感度、特异度、阳性预测值、阴性预测值、约登指数和Kappa 值分别为69.03%(78/113)、34.31%(175/510)、18.89%(78/413)、83.33%(175/210)、0.03和-0.76。结论 结核病症状筛查在HIV感染/AIDS患者中确诊活动性结核病阳性结果与专家组确诊患者比较的约登指数、Kappa值均较低,但症状筛查投入低、操作简单且有效,特别是在医疗资源特别匮乏的边远地区及少数民族地区,可作为排查结核病的预警指标。

Value of tuberculin test in screening tuberculosis infection in HIV infected/AIDS patients in Butuo County,Sichuan Province

Objective To analyze the application value of tuberculin (PPD) test in screening tuberculosis infection in HIV infected/AIDS patients in Butuo, Liangshan Yi Autonomous Prefecture. Methods A total of 688 patients who were followed up and had taken immunosuppressant therapy >1 month were enrolled, among 2159 HIV/AIDS patients managed in the “Thirteenth Five-Year Plan” National Science and Technology Major Project in Jiudu, Mu’er and Te Muli Town in Butuo between December 2018 and August 2019. Questionnaire, PPD test, X-ray chest and CD4⁺ T lymphocyte count were conducted. MTB etiology test was performed on eligible subjects. Of the 688 cases, 175 were without verification of PPD test results, 40 were not examed by X-ray and had no etiology basis, 7 were infected by nontuberculous mycobacteria, and 466 cases were included finally. SPSS 21.0 software was used to analyze the PPD test results (the average diameter of skin scleroma ≥5 mm was positive) and the status of active pulmonary tuberculosis or latent tuberculosis infection (LTBI) judged by the expert group, to detect the efficiency of PPD test for active pulmonary tuberculosis (including sensitivity, specificity, positive predictive value, negative predictive value, agreement rate) based on diagnosed active pulmonary tuberculosis cases. The relationship between positive rate of PPD test and whether complicated with active pulmonary tuberculosis or not, as well as comparison of different CD4⁺ T lymphocyte counts and prevalence, were detected by χ² test. P<0.05 was statistically significant. Results Among the 466 patients, 377 (80.90%) were negative in PPD test, 14 (3.00%) were generally positive, 29 (6.23%) were moderately positive, 46 (9.87%) were strongly positive and the positive rate was 19.10% (89/466), all of them were consistent with tuberculosis infection. By tuberculosis screening and diagnosis from expert group, 89 cases (19.10%) were active pulmonary tuberculosis, including 57 LTBI cases (12.23% (57/466)). Based on diagnosis from expert group, the sensitivity, specificity and consistent rate of PPD test for active tuberculosis were 35.96% (32/89), 84.88% (320/377), and 75.54% (352/466), respectively. The positive rate of PPD test in HIV/AIDS patients complicated with active pulmonary tuberculosis was significantly higher than that in patients without active pulmonary tuberculosis (35.96% (32/89) vs. 15.12% (57/377);χ²=20.827, P=0.000). Furthermore, only when CD4⁺ T lymphocyte count was more than 500 count/μl, the complicated rate was significantly higher (52.00% (13/25) vs. 16.67% (19/114); χ²=14.444, P=0.000). Conclusion As the sensitivity of PPD test to detect active tuberculosis was not high, other examinations should be combined.But the positive rates of PPD test was positively correlated with the count of CD4⁺T lymphocytes,and the specificity was high, negative results may also indicate non-tuberculosis infection. Therefore, it may still be used as an effective method in areas with high HIV prevalence and limited health resources.