National Public Health and Epidemiology Unit, National Centre for Infectious Diseases, Singapore.
National Tuberculosis Registry, National Tuberculosis Programme, Singapore.
Int J Infect Dis. 2024 Oct;147:107166. doi: 10.1016/j.ijid.2024.107166. Epub 2024 Jul 9.
Contacts of patients with infectious tuberculosis (TB) testing positive on interferon-gamma release assay (IGRA) are followed up to exclude active disease. However, identifying factors that predispose IGRA-negative contacts to TB could improve screening and follow-up strategies in a medium TB burden country such as Singapore.
We conducted a retrospective study of IGRA-negative contacts aged ≥2 years identified during contact investigation between January 2014 and December 2022. We examined the risk factors associated with developing active TB among contacts previously testing IGRA-negative, using univariate and multivariable logistic regression and odds ratios with 95% confidence intervals.
Of 60,377 IGRA-negative contacts, 150 developed TB disease, and half were notified within 23 months of index patient diagnosis. IGRA-negative contacts of a smear-positive index patient were more likely to develop TB. Independent risk factors for TB were age >50 years, Malay ethnicity, having diabetes or end-stage renal failure, a "family" relationship with the index patient, or exposure in a dormitory or nursing home.
Identifying risk factors could help optimise follow-up strategies and preventive treatment in IGRA-negative individuals. The incidence rate of TB in this group was 150 per 100,000 population, substantially higher than in the community, with a median 92 weeks to develop disease. Findings suggest that follow-up should be extended to 24 months for contacts with these risk factors.
对干扰素-γ释放试验(IGRA)阳性的传染性肺结核(TB)患者的接触者进行随访,以排除活动性疾病。然而,确定使 IGRA 阴性接触者易患 TB 的因素,可以改善在新加坡等中 TB 负担国家的筛查和随访策略。
我们对 2014 年 1 月至 2022 年 12 月期间接触者调查中发现的年龄≥2 岁的 IGRA 阴性接触者进行了回顾性研究。我们使用单变量和多变量逻辑回归以及 95%置信区间的比值比,检查了先前 IGRA 阴性接触者发生活动性 TB 的相关危险因素。
在 60377 名 IGRA 阴性接触者中,有 150 人患上了 TB 病,其中一半是在索引患者诊断后 23 个月内通知的。IGRA 阴性的痰涂片阳性索引患者的接触者更有可能患上 TB。TB 的独立危险因素是年龄>50 岁、马来族裔、患有糖尿病或终末期肾病、与索引患者有“家庭”关系、或在宿舍或疗养院接触。
确定危险因素可以帮助优化 IGRA 阴性个体的随访策略和预防治疗。该组的 TB 发病率为每 100,000 人 150 例,远高于社区,中位发病时间为 92 周。研究结果表明,对于具有这些危险因素的接触者,随访时间应延长至 24 个月。