Mphaphlele Matsie, Dharmadhikari Ashwin S, Jensen Paul A, Rudnick Stephen N, van Reenen Tobias H, Pagano Marcello A, Leuschner Wilhelm, Sears Tim A, Milonova Sonya P, van der Walt Martie, Stoltz Anton C, Weyer Karin, Nardell Edward A
1 MDR-TB Program, JHPIEGO, Pretoria, South Africa.
2 Division of Pulmonary and Critical Care Medicine and.
Am J Respir Crit Care Med. 2015 Aug 15;192(4):477-84. doi: 10.1164/rccm.201501-0060OC.
Transmission is driving the global tuberculosis epidemic, especially in congregate settings. Worldwide, natural ventilation is the most common means of air disinfection, but it is inherently unreliable and of limited use in cold climates. Upper room germicidal ultraviolet (UV) air disinfection with air mixing has been shown to be highly effective, but improved evidence-based dosing guidelines are needed.
To test the efficacy of upper room germicidal air disinfection with air mixing to reduce tuberculosis transmission under real hospital conditions, and to define the application parameters responsible as a basis for proposed new dosing guidelines.
Over an exposure period of 7 months, 90 guinea pigs breathed only untreated exhaust ward air, and another 90 guinea pigs breathed only air from the same six-bed tuberculosis ward on alternate days when upper room germicidal air disinfection was turned on throughout the ward.
The tuberculin skin test conversion rates (>6 mm) of the two chambers were compared. The hazard ratio for guinea pigs in the control chamber converting their skin test to positive was 4.9 (95% confidence interval, 2.8-8.6), with an efficacy of approximately 80%.
Upper room germicidal UV air disinfection with air mixing was highly effective in reducing tuberculosis transmission under hospital conditions. These data support using either a total fixture output (rather than electrical or UV lamp wattage) of 15-20 mW/m(3) total room volume, or an average whole-room UV irradiance (fluence rate) of 5-7 μW/cm(2), calculated by a lighting computer-assisted design program modified for UV use.
传播正在推动全球结核病流行，尤其是在集体环境中。在全球范围内，自然通风是最常见的空气消毒方式，但它本质上不可靠，在寒冷气候下用途有限。已证明带有空气混合的上部空间杀菌紫外线（UV）空气消毒非常有效，但需要改进基于证据的剂量指南。
测试带有空气混合的上部空间杀菌空气消毒在实际医院条件下减少结核病传播的效果，并确定相关应用参数，作为拟议新剂量指南的基础。
在7个月的暴露期内，90只豚鼠仅呼吸未经处理的病房排气，另外90只豚鼠在病房全天开启上部空间杀菌空气消毒时，隔天仅呼吸来自同一六床结核病病房的空气。
比较两个舱室的结核菌素皮肤试验转化率（>6毫米）。对照舱室中皮肤试验转为阳性的豚鼠的风险比为4.9（95%置信区间，2.8 - 8.6），有效率约为80%。
带有空气混合的上部空间杀菌紫外线空气消毒在医院条件下对减少结核病传播非常有效。这些数据支持使用15 - 20毫瓦/立方米总房间体积的总灯具输出（而非电功率或紫外线灯瓦数），或通过为紫外线使用修改的照明计算机辅助设计程序计算得出的5 - 7微瓦/平方厘米的全房间平均紫外线辐照度（通量率）。
