Catanzaro A
Am Rev Respir Dis. 1982 May;125(5):559-62. doi: 10.1164/arrd.1982.125.5.559.
Hospital employees are at risk of contracting tuberculosis from patients. The undiagnosed case with sputum-smear positive for acid-fast bacilli is the usual source case. However, even the smear-negative patient may pose a risk. This was documented by a high rate of skin test conversion in hospital staff exposed to a smear-negative, culture-positive patient in a respiratory intensive care unit. The patient required bronchoscopy, intubation, and assisted ventilation. Of susceptible hospital staff members who were exposed to the index case, 14 of 45 (31%) converted their PPD skin test. Ten of 13 (77%) susceptible hospital staff members present at the time of bronchoscopy converted, compared with 4 of 32 (12.5%) who were not present at bronchoscopy (Fischer's exact test p = 0.0006). Rough calculations suggest that during the bronchoscopy and intubation the index case generated at least 249 infectious units per hour. At the ventilation levels in this area, this resulted in 1 infectious unit of tuberculosis in each 68.9 cubic feet of air. Improved ventilation, high efficiency filters, and ultraviolet irradiation are effective recommended ways to clean the air of infectious particles.
医院员工有感染患者结核病的风险。痰涂片抗酸杆菌阳性的未确诊病例是常见的传染源。然而，即使是涂片阴性的患者也可能有风险。这一点在一家呼吸重症监护病房中接触涂片阴性、培养阳性患者的医院工作人员中皮肤试验转化率很高得到了证实。该患者需要进行支气管镜检查、插管和辅助通气。在接触该首例病例的易感医院工作人员中，45人中有14人（31%）的结核菌素皮肤试验结果发生了转换。在支气管镜检查时在场的13名易感医院工作人员中有10人（77%）发生了转换，而在支气管镜检查时不在场的32人中有4人（12.5%）发生了转换（费舍尔精确检验p = 0.0006）。粗略计算表明，在支气管镜检查和插管过程中，首例病例每小时至少产生249个感染单位。在该区域的通风水平下，这导致每68.9立方英尺空气中有1个结核感染单位。改善通风、高效过滤器和紫外线照射是推荐的有效清除空气中感染性颗粒的方法。
