Peng Liai, Mei Jinzhou, Hu Fangxiang, Xie Mingbin, Liu Zhenyang, Guo Yanfang, Yang Chongguang, Wang Yunxia
Department of Tuberculosis Control and Prevention, Bao'an District Hospital for Chronic Diseases Prevention and Cure, Shenzhen, Guangdong, China.
School of Public Health (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Shenzhen, Guangdong, China.
Front Public Health. 2025 Sep 4;13:1655711. doi: 10.3389/fpubh.2025.1655711. eCollection 2025.
Tuberculosis (TB) outbreaks in confined settings such as schools pose significant public health challenges due to the potential for rapid transmission among closely interacting individuals. In December 2018, a senior high school student in Shenzhen City, China, was diagnosed with etiological positive TB, prompting an investigation that extended until November 2024. This study aimed to analyze the outbreak's characteristics, identify its causes, and provide insights for timely identification and management of similar clusters.
The confirmed, clinically diagnosed, and suspected cases of TB were identified according to the "Tuberculosis diagnosis WS288-2017" criteria. Epidemiological investigations of TB cases included close contact screening via symptom assessment, TST, and chest radiography. Moderately TST-positive contacts underwent IGRA confirmation for preventive therapy eligibility, while MIRU-VNTR genotyping of culture-positive isolates delineated transmission networks. The Chi-square test or Fisher's exact test was employed to analyze changes in TST positivity rates and differences in TB incidence rates.
A total of six TB cases were detected in the high school, with five screenings conducted over the study period. Misdiagnosis caused a near-three-month delay from symptom onset to confirmed TB in the index case. Among the five newly diagnosed patients, four were in the same class as the index case, and one was in an adjacent class. These two classes are located on the middle horizontal line of the "B"-shaped teaching building. For the indicated case's class, the positive rate of TST in the second screening (35.85, 95% CI: 23.49-19.25%) was significantly higher than in the first screening (8.93, 95% CI: 3.33-20.37%) (χ = 11.493, < 0.001). MIRU-VNTR genotyping of four clinical isolates identified concordant non-Beijing strains with matching profiles at 11/12 loci (excluding VNTR3232), demonstrating a single transmission chain.
This outbreak was a cluster epidemic driven by misdiagnosis, poor ventilation, and insufficient routine prevention measures. Establishing long-term close-contact monitoring and secondary screening is crucial for identifying infections missed during the initial window period, thereby mitigating the spread of TB in similar settings and improving outbreak management strategies.
在学校等封闭环境中发生的结核病（TB）疫情，由于密切接触的个体之间存在快速传播的可能性，对公共卫生构成了重大挑战。2018年12月，中国深圳市一名高中生被诊断为病原学阳性结核病，促使展开一项持续至2024年11月的调查。本研究旨在分析此次疫情的特征，找出其成因，并为及时识别和管理类似聚集性病例提供见解。
根据《WS288-2017结核病诊断》标准确定确诊、临床诊断和疑似结核病病例。结核病病例的流行病学调查包括通过症状评估、结核菌素皮肤试验（TST）和胸部X线摄影进行密切接触者筛查。TST中度阳性的接触者接受干扰素释放试验（IGRA）以确定是否符合预防性治疗条件，而对培养阳性菌株进行多位点可变数目串联重复序列分析（MIRU-VNTR）基因分型以描绘传播网络。采用卡方检验或Fisher精确检验分析TST阳性率的变化以及结核病发病率的差异。
该高中共检测到6例结核病病例，在研究期间进行了5次筛查。误诊导致首例病例从症状出现到确诊结核病延迟了近三个月。在5例新诊断患者中，4例与首例病例同班，1例在相邻班级。这两个班级位于“B”形教学楼的中间水平线位置。对于首例病例所在班级，第二次筛查时TST阳性率（35.85，95%CI：23.49-19.25%）显著高于第一次筛查（8.93，95%CI：3.33-20.37%）（χ²=11.493，P<0.001）。对4株临床分离株进行MIRU-VNTR基因分型，在11/12个位点（不包括VNTR3232）鉴定出具有匹配图谱的一致非北京菌株，表明存在单一传播链。
此次疫情是由误诊、通风不良和常规预防措施不足导致的聚集性流行。建立长期密切接触者监测和二次筛查对于识别初始窗口期漏诊的感染至关重要，从而减轻结核病在类似环境中的传播并改善疫情管理策略。
