Testing Interventions to Human-Generated Occupational Airborne Infections

描述(申请人提供)：目前推荐的大多数控制空气传播感染的干预措施从未针对人产生的传染性气雾剂进行过严格的测试，部分原因是无法在现实生活条件下对大多数空气传播病原体的空气样本进行定量测试。我们计划在南非一个独特的空气传播感染研究(AIR)设施中，将传染性多药耐药结核病(MDR-TB)患者作为空气传播感染的原型进行研究，该设施旨在通过使用定量的豚鼠空气样本来有效地测试感染控制干预措施的有效性。在两个相同的房间中的一个房间里的豚鼠每隔一天暴露在三个两床房间和航空患者套间的公共区域的排气中。每隔一天在病房实施感染控制干预。豚鼠曝气室A仅在干预操作时接受来自病房的空气，而曝气室B仅在控制条件下接受来自病房的空气。通过结核菌素皮肤试验确定的两个腔室中的豚鼠感染率的差异是干预效果的一种衡量标准。需要检验的假设是，两项快速反应干预措施(对感染者戴上口罩和便携式房间空气净化器)和一项预先计划的预防干预措施(上层房间紫外线空气消毒)可以有效地降低人与人之间空气传播的风险。具体目标：(1)确定为感染者戴上的外科口罩在减少传播方面是否至少有效50%。(2)确定商用便携式空气消毒装置是否至少有效75%。我们的目标是建立清洁空气传送率和房间空气消毒之间的关系，独立于所使用的特定设备。我们将测试传统的高效空气过滤器装置和为外层空间使用而开发的低维护的新型静电空气净化技术。(3)确定上层房间UVGI是否至少有效75%，以及房间空气混合和低湿度是否是关键的疗效因素。意义：流感、SARS、天花和耐多药结核病是工人新出现的空气传播传染病。耐多药结核病患者和空气设施中的定量豚鼠空气采样提供了一种独特的模式，用于在控制的感染源强度(隔日策略)、环境(空气设施)和宿主易感性(豚鼠)的条件下，有效地测试传统和新型感染控制干预措施，以保护工人和其他建筑物居住者。耐多药结核病的检测结果可能适用于完全或部分通过空气传播的其他感染。

DESCRIPTION (provided by applicant): Most currently recommended interventions to control airborne infection have never been rigorously tested against human-generated infectious aerosols, in part because of an inability to quantitatively air sample for most airborne pathogens under real life conditions. We plan to study patients with infectious multi-drug resistant tuberculosis (MDR-TB) as a prototype airborne infection in a unique Airborne Infections Research (AIR) facility in South Africa designed to efficiently test the efficacy of infection control interventions through the use of quantitative guinea pig air sampling. Guinea pigs in one of two identical chambers are exposed on alternate days to the exhaust air from three 2-bed rooms and the common area of the AIR patient suite. The infection control intervention is applied in the patient rooms on alternate days. Guinea pig exposure chamber A receive air from the patient rooms only when the intervention is operative, while exposure chamber B receives air from the patient rooms only under control conditions. The difference in the infection rate of guinea pigs in the two chambers, as determined by tuberculin skin testing, is a measure of the efficacy of the intervention. The HYPOTHESES to be tested are that two rapid response interventions (face masks on infectious persons and portable room air cleaning machines), and one pre-planned preventive interventions (upper room UV air disinfection) can effectively reduce the risk of person to person airborne transmission. SPECIFIC AIMS: (1) To determine if surgical masks on infectious individuals are at least 50% effective in reducing transmission. (2) To determine if commercial portable air disinfection units are at least 75% effective. We aim to establish a relationship between clean air delivery rate and room air disinfection, independent of the specific device used. We will test both a conventional HEPA filter unit and novel low-maintenance electrostatic air decontamination technology developed for use in outer space. (3) To determine if upper room UVGI is at least 75% effective, and whether room air mixing and low humidity are critical efficacy factors. SIGNIFICANCE: Influenza, SARS, smallpox, and MDR-TB are among the emerging infectious airborne treats to workers. MDR-TB patients and quantitative guinea pig air sampling in the AIR facility provide a unique model for the efficient testing under conditions of controlled infectious source strength (the alternate day strategy), environment (the AIR facility), and host susceptibility (the guinea pigs), of both conventional and novel infection control interventions to protect workers and other building occupants. Test results obtained with MDR-TB may be applicable to other infections that are completely or partially airborne.