Department of Preventive and Social Medicine, Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER), Puducherry, India.
Department of Preventive and Social Medicine, Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER), Puducherry, India.
Indian J Tuberc. 2023 Jan;70(1):12-16. doi: 10.1016/j.ijtb.2022.03.011. Epub 2022 Mar 16.
Latent tuberculosis infection (LTBI) is a mycobacterial infection defined on the basis of cellular immune response to mycobacterial antigens. The tuberculin skin test (TST) and the Interferon-Gamma Release Assay (IGRA) are the two tests currently used to establish the diagnosis of LTB. Literature suggests that a study regarding tuberculosis (TB) infection among women of reproductive age group is limited.
Female household contact, married, aged 18-49 years underwent written consent form and are screened for LTBI using the TST and IGRA. Participants are injected with TST [5 tuberculin unit (TU), purified protein derivative (PPD)] and IGRA [QuantiFERON®-TB Gold Plus kit (QFT-Plus)]. All the household contacts were followed-up for one year for incident TB cases. Statistical analysis was done using STATA version 14 (StataCorp., Texas, USA). Cohen's kappa test was used to determine the agreement between two tests.
The prevalence of LTBI was found to be 69% (either TST or IGRA positive). Positivity rate of IGRA was higher when compared to that of TST. Out of 139 participants, 68 (49%) tested positive for TST, 80 (57.6%) tested positive for IGRA and 52 (37.4%) tested positive for both. Discordant results were observed in about two fifth of the study population and there was poor agreement between the two tests.
Longitudinal studies are required to detect incident TB cases to evaluate the usefulness of these tests. The study was found that IGRA is more consistent to diagnosis of latent tuberculosis infection than the TST. Such studies can also be performed in varied settings among different populations which would help us to improve the diagnosis of LTBI and consequently help in TB control.
潜伏性结核感染（LTBI）是一种基于对分枝杆菌抗原的细胞免疫反应定义的分枝杆菌感染。结核菌素皮肤试验（TST）和干扰素-γ释放试验（IGRA）是目前用于确定 LTBI 诊断的两种检测方法。文献表明，关于育龄期妇女结核感染的研究有限。
对年龄在 18-49 岁的女性家庭接触者、已婚者进行书面知情同意书，并使用 TST 和 IGRA 筛查 LTBI。参与者接受 TST [5 结核菌素单位（TU），纯蛋白衍生物（PPD）]和 IGRA [QuantiFERON®-TB Gold Plus 试剂盒（QFT-Plus）]注射。所有家庭接触者在一年内都接受了新发病例的 TB 检测。使用 STATA 版本 14（StataCorp.，德克萨斯州，美国）进行统计分析。采用 Cohen's kappa 检验来确定两种检测方法的一致性。
LTBI 的患病率为 69%（TST 或 IGRA 阳性）。IGRA 的阳性率高于 TST。在 139 名参与者中，68 名（49%）TST 阳性，80 名（57.6%）IGRA 阳性，52 名（37.4%）两种方法均阳性。研究人群中约有五分之二的人出现了不一致的结果，两种检测方法之间的一致性较差。
需要进行纵向研究来检测新发病例，以评估这些检测方法的有效性。研究发现，IGRA 比 TST 更有助于 LTBI 的诊断。此类研究还可以在不同人群的不同环境中进行，这将有助于提高 LTBI 的诊断，从而有助于控制结核病。
