RAPID: Flood-related pathogen risk models appropriate for low resource settings

中国南方最近发生的严重洪灾影响了湖南省数百万人，并增加了水传播传染病的威胁。由于城市下水道系统和农村厕所溢出，以及农业动物的粪便被冲入河流和小溪，洪水条件可以调动病原体。这个快速项目旨在提高我们对重大洪水事件后微生物风险的理解和预测能力。紧急救援人员面临着重大挑战，即在洪水事件发生后，特别是在环境数据有限的情况下，估计微生物风险的“时间和空间”规模。与此同时，人们也提出了一个问题，即微生物风险升高何时恢复正常--也就是说，何时返回洪水泛滥地区是安全的？研究人员将与湖南和邻近省份的同事密切合作，开发能够估计洪水后饮用水中隐孢子虫暴露风险的模型。隐孢子虫是一种重要的研究生物，因为它是美国和中国风险管理人员的高度优先病原体，它是洪水期间急性腹泻的记录原因，它在恶劣条件下持续存在于环境中，并且对用于处理饮用水的消毒剂具有高度抗性。即使在非洪水条件下，该病原体也威胁着中国、美国和世界各地饮用水系统的安全供水。湖南的紧急情况提供了一个狭窄的数据窗口，可以在整个洪水区的关键地点获得环境监测数据。这些数据将用于开发和评估洪水排放模型，隐孢子虫污染，命运和运输。通过饮用水摄入隐孢子虫卵囊的风险将在洪水条件下计算，并与标称流量条件进行比较，以评估洪水在升高或降低风险方面的作用。研究人员将研究特定景观在洪水条件下减弱或加剧风险的作用。最后，模型将用于隔离特定流程的角色（如在大流量下病原体的稀释），这会导致与洪水有关的风险，以及隐孢子虫卵囊浓度恢复到感染前水平所需的时间。将根据污染源的位置和影响隐孢子虫在水体中生存的因素来研究洪水。该项目的结果将与制定战略高度相关，减轻洪水易发地区未来的洪水风险。研究人员将开发新的工具来建模和预测与洪水相关的微生物风险，这将提高我们对极端事件如何改变微生物水质的理解。该研究将通过改善湖南洪水易发地区与洪水相关的风险特征，立即造福于中国南方的居民。美国和其他地方受洪水影响的人口也将获得重大利益。在卡特里娜飓风、2011年密西西比河洪水以及历史上许多类似的情况下，确定洪水后返回的安全时间是一个挑战。因此，该项目在洪水相关微生物风险方面的科学知识的根本性进步将在亚洲以外地区受益，通过更好地了解病原体在洪水期间如何传播以及如何最大限度地减少相关微生物风险，改善我们对美国和其他地区洪水状况的反应。

1249250RemaisRecent severe flooding in southern China has affected millions of people in Hunan province and has raised the threat of waterborne infectious diseases. Pathogens can be mobilized by flood conditions as urban sewerage systems and rural latrines overflow, and manure from agricultural animals is washed into rivers and streams. This RAPID project aims to improve our understanding of, and our ability to predict, the microbiological risks that follow a major flood event. Emergency responders are faced with the significant challenge of estimating the scale "in time and space" of microbiological risk following a flooding event, especially where environmental data are limited. At the same time, questions arise as to when elevated microbiological risks return to normal - that is, when is it safe to return to flooded areas? The researchers will collaborate closely with colleagues in Hunan and neighboring provinces to develop models capable of estimating the risk of Cryptosporidium exposure in drinking water following the flood. Cryptosporidium is an important organism to study because it is a high priority pathogen for US and Chinese risk managers, it is a documented cause of acute diarrhea during floods, it persists in the environment under harsh conditions, and it is highly resistant to disinfectants used to treat drinking water. Even under non-flood conditions, the pathogen threatens delivery of safe water in China, the US, and in drinking water systems throughout the world. The emergency situation in Hunan provides a narrow window of data availability in which environmental monitoring data can be obtained at key locations throughout the flood zone. These data will be used to develop and evaluate models of flood discharge, and Cryptosporidium contamination, fate and transport. The risk of Cryptosporidium oocyst ingestion through drinking water will be calculated under flood conditions and compared to nominal flow conditions to assess the role of the flood in elevating or lowering risk. Researchers will examine the role of specific landscapes in attenuating or intensifying risk under flood conditions. Finally, the models will be used to isolate the role of specific processes (like dilution of pathogens under heavy flows) that drive flood-related risks, and the time required for Cryptosporidium oocyst concentration to return to pre-flood will be examined in relation to the location of sources of contamination and factors that affect Cryptosporidium survival in the water column.Results from the project will be highly relevant to devising strategies to moderate future flood risks in flood-prone regions. The researchers will develop new tools for the modeling and prediction of flood-related microbiological risks that will improve our understanding of how extreme events can alter microbiological water quality. The research will immediately benefit the residents of southern China through improved characterization of flood-related risks in the flood-prone regions of Hunan. Significant benefits will also accrue to populations affected by flooding in the US and elsewhere. Determining when it was safe to return post-flooding was a challenge following Hurricane Katrina, the Mississippi river floods in 2011 and in many similar circumstances historically. Thus, the fundamental advancements of scientific knowledge on flood-related microbiological risks from this project will have benefits outside of Asia, improving our response to flood conditions in the US and elsewhere through improved understanding of how pathogens spread during floods, and how the associated microbiological risks can be minimized.