Southeastern National Tuberculosis Center, Emerging Pathogens Institute, Room 257, University of Florida, Gainesville, FL 32610, USA.
Am J Respir Crit Care Med. 2012 Sep 1;186(5):450-7. doi: 10.1164/rccm.201203-0444OC. Epub 2012 Jul 12.
Mycobacterium tuberculosis is transmitted by infectious aerosols, but assessing infectiousness currently relies on sputum microscopy that does not accurately predict the variability in transmission.
To evaluate the feasibility of collecting cough aerosols and the risk factors for infectious aerosol production from patients with pulmonary tuberculosis (TB) in a resource-limited setting.
We enrolled subjects with suspected TB in Kampala, Uganda and collected clinical, radiographic, and microbiological data in addition to cough aerosol cultures. A subset of 38 subjects was studied on 2 or 3 consecutive days to assess reproducibility.
M. tuberculosis was cultured from cough aerosols of 28 of 101 (27.7%; 95% confidence interval [CI], 19.9-37.1%) subjects with culture-confirmed TB, with a median 16 aerosol cfu (range, 1-701) in 10 minutes of coughing. Nearly all (96.4%) cultivable particles were 0.65 to 4.7 μm in size. Positive aerosol cultures were associated with higher Karnofsky performance scores (P = 0.016), higher sputum acid-fast bacilli smear microscopy grades (P = 0.007), lower days to positive in liquid culture (P = 0.004), stronger cough (P = 0.016), and fewer days on TB treatment (P = 0.047). In multivariable analyses, cough aerosol cultures were associated with a salivary/mucosalivary (compared with purulent/mucopurulent) appearance of sputum (odds ratio, 4.42; 95% CI, 1.23-21.43) and low days to positive (per 1-d decrease; odds ratio, 1.17; 95% CI, 1.07-1.33). The within-test (kappa, 0.81; 95% CI, 0.68-0.94) and interday test (kappa, 0.62; 95% CI, 0.43-0.82) reproducibility were high.
A minority of patients with TB (28%) produced culturable cough aerosols. Collection of cough aerosol cultures is feasible and reproducible in a resource-limited setting.
结核分枝杆菌通过传染性气溶胶传播，但目前评估传染性依赖于痰显微镜检查，该检查不能准确预测传播的变异性。
在资源有限的环境中，评估从肺结核（TB）患者中收集咳嗽气溶胶的可行性和传染性气溶胶产生的危险因素。
我们在乌干达坎帕拉招募了疑似 TB 患者，并收集了临床、影像学和微生物学数据，以及咳嗽气溶胶培养物。38 名受试者的亚组连续 2 或 3 天进行研究，以评估可重复性。
从 101 名培养确诊的 TB 患者中的 28 名（27.7%；95%置信区间 [CI]，19.9-37.1%）患者的咳嗽气溶胶中培养出结核分枝杆菌，在 10 分钟咳嗽时，中位数为 16 个气溶胶 cfu（范围 1-701）。几乎所有（96.4%）可培养的颗粒大小为 0.65 至 4.7 μm。阳性气溶胶培养物与较高的卡诺夫斯基表现评分（P=0.016）、较高的痰抗酸杆菌涂片显微镜分级（P=0.007）、液体培养阳性时间较短（P=0.004）、更强的咳嗽（P=0.016）和较短的 TB 治疗时间（P=0.047）有关。在多变量分析中，与脓性/黏液脓性（与脓性/黏液脓性相比）痰液相比，咳嗽气溶胶培养物与唾液/黏膜唾液（odds ratio，4.42；95% CI，1.23-21.43）和低阳性天数（每减少 1 天；比值比，1.17；95% CI，1.07-1.33）相关。日内（kappa，0.81；95% CI，0.68-0.94）和日间测试（kappa，0.62；95% CI，0.43-0.82）的可重复性均较高。
少数结核病患者（28%）产生可培养的咳嗽气溶胶。在资源有限的环境中，收集咳嗽气溶胶培养物是可行且可重复的。
