Molecular Detection of Airborne Mycobacterium tuberculosis in South African High Schools
Molecular Detection of Airborne Mycobacterium tuberculosis in South African High Schools
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DOI：
10.1164/rccm.202102-0405oc
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发表时间：
2022-02-01
影响因子：
24.7
通讯作者：
Hatherill, Mark
中科院分区：
文献类型：
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作者：
Bunyasi, Erick W.;Middelkoop, Keren;Hatherill, Mark
理由：南非青少年结核病负担很重。目前还不知道，如果学校是结核分枝杆菌（MTB）transmission.Objectives的高风险设置：检测空气中的MTB基因组DNA在classmes.Methods：我们研究了72间教室占用的2,262名学生在两所南非学校。进行中位40（四分位距[IQR]，35-54）分钟的高容量空气过滤，并通过靶向MTB差异区域9（RD 9）的液滴数字PCR（ddPCR）进行分析，同时进行CO2浓度测量。课堂数据以公共卫生诊所为基准。同意接受个体结核病筛查的学生完成问卷调查，如果症状阳性，则采集痰液（Xpert MTB/RIF Ultra）。测量和主要结果：ddPCR检测在13/72（18.1%）教室和4/39（10.3%）临床测量中呈阳性（P= 0.276）。教室环境CO2浓度中位数为886（IQR，747-1223）ppm，诊所为490（IQR，405-587）ppm（P < 0.001）。MTB RD 9的平均空气浓度在教室中为3.61拷贝/180，000升，而在诊所中为1.74拷贝/180，000升（P= 0.280）。在所有教室中，在35分钟的标准课程中，占用者吸入一个MTB RD 9副本的平均风险估计为0.71%。在1，836/2，262（81.2%）同意筛查的学生中，21/90（23.3%）有症状的学生产生了痰液样本，其中1例为Xpert MTB/RIF Ultra阳性。教室暴露的瞬时风险与公共卫生诊所的风险相似。
Rationale: South African adolescents carry a high tuberculosis disease burden. It is not known if schools are high-risk settings for Mycobacterium tuberculosis (MTB) transmission.Objectives: To detect airborne MTB genomic DNA in classrooms.Methods: We studied 72 classrooms occupied by 2,262 students in two South African schools. High-volume air filtration was performed for median 40 (interquartile range [IQR], 35-54) minutes and assayed by droplet digital PCR (ddPCR)-targeting MTB region of difference 9 (RD9), with concurrent CO2 concentration measurement. Classroom data were benchmarked against public health clinics. Students who consented to individual tuberculosis screening completed a questionnaire and sputum collection (Xpert MTB/RIF Ultra) if symptom positive. Poisson statistics were used for MTB RD9 copy quantification.Measurements and Main Results: ddPCR assays were positive in 13/72 (18.1%) classrooms and 4/39 (10.3%) clinic measurements (P= 0.276). Median ambient CO2 concentration was 886 (IQR, 747-1223) ppm in classrooms versus 490 (IQR, 405-587) ppm in clinics (P < 0.001). Average airborne concentration of MTB RD9 was 3.61 copies per 180,000 liters in classrooms versus 1.74 copies per 180,000 liters in clinics (P= 0.280). Across all classrooms, the average risk of an occupant inhaling one MTB RD9 copy was estimated as 0.71% during one standard lesson of 35 minutes. Among 1,836/2,262 (81.2%) students who consented to screening, 21/90 (23.3%) symptomatic students produced a sputum sample, of which one was Xpert MTB/RIF Ultra positive.Conclusions: Airborne MTB genomic DNA was detected frequently in high school classrooms. Instantaneous risk of classroom exposure was similar to the risk in public health clinics.