Modeling the Effects of the Environment on Enteric Pathogen Dynamics

描述(由申请人提供)：人们越来越认识到环境途径对于呼吸道、肠道和其他病原体在人与人之间传播的重要性。这些间接传播链可能涉及水、食物、空气和甲烷，所有这些都为干预提供了天然的点。因此，有必要开发明确描述病原体动力学和人类在这些环境中接触病原体的动力学的传播模型。我们称之为环境感染传播系统(EITS)模型。我们建议在一系列空间和时间尺度上开发和检查这样的模型，这取决于代理人在不同环境中的生存能力以及排泄和暴露的时间模式。我们专注于肠道病原体，因为它们：1)利用广泛的环境尺度；2)存在广泛的人类和环境数据；3)肠道疾病具有重大的全球和国内公共卫生重要性。我们建议在过去10年工作的基础上，将传播模型应用于微生物风险评估，这促进了美国环保局的监管政策，最近还通过我们在推进微生物风险评估中心(CAMRA)的工作。我们的分析包括国内环境中的传播研究，如美国的隐孢子虫、MRSA和诺沃克病毒，以及国际环境中的霍乱和腹泻疾病，如海地、泰国和厄瓜多尔。到目前为止，在我们的工作中，我们逐一审查了不同类型的环境媒介传播。在这里，我们将开发一个统一的框架，将环境传播整合在广泛的时间和空间传播尺度上。具体地说，我们提出了以下具体目标：1)开发一种关注长时间尺度的环境感染传播系统(EITS)建模方法，如水媒传播；2)开发一种关注短时间尺度(如Fomite传播)的EITS建模方法；以及3)开发一种集成这些跨越广泛空间和时间尺度的不同传播途径的框架。由于许多干预措施都是环境驱动的(如表面清洁、饮用水和废水处理)，该框架将为政策和干预措施提供详细的环境洞察和指导。

DESCRIPTION (provided by applicant): There has been an increasing appreciation of the importance of environmental pathways for the human-to-human transmission of respiratory, enteric, and other pathogens. These indirect transmission chains may involve water, food, air, and fomites, all of which provide natural points for intervention. There is a need, therefore, to develop transmission models that explicitly describe pathogen dynamics and the dynamics of human contact with pathogens in these environments. We call these environmental infection transmission system (EITS) models. We propose to develop and examine such models across a range of spatial and temporal scales, as determined by agent survivability in different environments and temporal patterns of excretion and exposure. We focus on enteric pathogens as they: 1) exploit a wide range of environmental scales; 2) there exists extensive human and environmental data; and 3) enteric diseases have major global and domestic public health importance. We propose to build upon our work in the past 10 years applying transmission models to microbial risk assessment that has advanced regulatory policy for the USEPA, and more recently through our work in the Center for Advancing Microbial Risk Assessment (CAMRA). Our analyses have included transmission studies in domestic settings such as Cryptosporidium, MRSA, and norovirus in the United States, as well as international settings such as cholera and diarrheal diseases in Haiti, Thailand, and Ecuador. In our work thus far we have examined distinct types of environmentally mediated transmission on a case-by-case basis. Here we will develop a unified framework integrating environmental transmission across a wide range of temporal and spatial transmission scales. Specifically, we propose the following specific aims: 1) To develop an environmental infection transmission systems (EITS) modeling approach that focuses on long timescales, such as waterborne transmission; 2) To develop an EITS modeling approach that focuses on short timescales, such as fomite transmission; and 3) To develop a framework that integrates these diverse transmission pathways that span across a wide range of spatial and temporal scales. As many interventions are environmentally driven (e.g. surface cleaning, drinking water and wastewater treatment) this framework will provide detailed environmental insight and guidance for policy and interventions.