Haas Charles N, Rycroft Taylor, Bibby Kyle, Casson Leonard
Water Environ Res. 2017 Apr 1;89(4):357-368. doi: 10.2175/106143017X14839994523181.
Current World Health Organization and Centers for Disease Control and Prevention guidance for the disposal of liquid waste from patients undergoing treatment for Ebola virus disease at hospitals in the U.S. is to manage patient excreta as ordinary wastewater without pretreatment. The potential for Ebolavirus transmission via liquid waste discharged into the wastewater environment is currently unknown, however. Possible worker inhalation exposure to Ebolavirus-contaminated aerosols in the sewer continues to be a concern within the wastewater treatment community. In this study, a quantitative microbial risk assessment was carried out to assess a sewer worker's potential risk of developing Ebola virus disease from inhalation exposure when performing standard occupational activities in a sewer line serving a hospital receiving Ebola patients where there is no pretreatment of the waste prior to discharge. Risk projections were estimated for four scenarios that considered the infectivity of viral particles and the degree of worker compliance with personal protective equipment guidelines. Under the least-favorable scenario, the median potential risk of developing Ebola virus disease from inhalation exposure to Ebolavirus-contaminated aerosols in the sewer is approximately 10-5.77 (with a first to third quartile range of 10-7.06 to 10-4.65), a value higher than many risk managers may be willing to accept. Although further data gathering efforts are necessary to improve the precision of the risk projections presented here, the results suggest that the potential risk that sewer workers face when operating in a wastewater collection system downstream from a hospital receiving Ebola patients warrants further attention, and that current authoritative guidance for Ebolavirus liquid waste disposal-to dispose in the sanitary sewer without further treatment-may be insufficiently protective of sewer worker safety.
世界卫生组织和美国疾病控制与预防中心目前针对美国医院中接受埃博拉病毒病治疗患者的液体废物处理给出的指导意见是，将患者排泄物作为普通废水处理，无需预处理。然而，埃博拉病毒通过排放到废水环境中的液体废物传播的可能性目前尚不清楚。污水处理行业仍担心工人在下水道中可能吸入受埃博拉病毒污染的气溶胶。在本研究中，开展了一项定量微生物风险评估，以评估在为接收埃博拉患者的医院服务的下水道中，下水道工人在进行标准职业活动时因吸入暴露而感染埃博拉病毒病的潜在风险，该医院的废物在排放前未进行预处理。针对四种情景估计了风险预测，这些情景考虑了病毒颗粒的传染性以及工人对个人防护设备指南的遵守程度。在最不利的情景下，下水道工人因吸入受埃博拉病毒污染的气溶胶而感染埃博拉病毒病的潜在风险中位数约为10-5.77（第一四分位数到第三四分位数范围为10-7.06至10-4.65），该值高于许多风险管理者可能愿意接受的水平。尽管需要进一步收集数据以提高此处给出的风险预测的准确性，但结果表明，下水道工人在接收埃博拉患者的医院下游的废水收集系统中作业时面临的潜在风险值得进一步关注，而且目前关于埃博拉病毒液体废物处理的权威指导意见——即未经进一步处理直接排入生活污水管道——可能对下水道工人安全的保护不足。
