Harmon Olivia A, Lott Megan E J, Holcomb David A, McGlohn Emily, Elliott Mark, White Kevin, Brown Joe
medRxiv. 2025 Jul 25:2025.07.25.25332164. doi: 10.1101/2025.07.25.25332164.
Rural sanitation deficits in the United States represent an important source of non-point source pollution and may present risks to public health. We propose an interrupted time series analysis to measure the effect of a town-wide sanitation expansion program on the release of pathogens to the environment. This work is expected to yield valuable insight into the potential for rural sanitation improvements to reduce pathogen releases and support public health and well-being.
We will conduct a longitudinal baseline study including quantitative measurement of key enteric pathogens and fecal indicator bacteria adjacent to households lacking adequate sanitation. As households connect to a new sewerage system serving the entire community, longitudinal household sampling will continue until crossover is complete. We will include concurrent comparison sites with existing appropriate sanitation as well as sites never receiving the intervention to monitor secular trends in pathogen releases during the study period.
We will compare the concentration of culturable in the environment pre- and post-intervention using a time series regression analysis suitable for an interrupted time series. We will couple pathogen measurements with quantitative microbial risk assessment to estimate the potential effect of the intervention on infection risks via key exposure pathways. A linked pre-post survey will focus on self-reported quality of life measures among households connecting to the system.
Informed consent will be obtained prior to data collection, with participants informed of study details and risks. Participation is completely voluntary, and identifiable data will be securely and separately stored from all other data. Each household will be offered a summary of their site-specific data. Deidentified results will be shared with the community in a public forum and published in peer-reviewed journals.
This study utilizes both molecular and culture-based environmental sampling with structured household and observational surveys to carefully assess the effects of a community-wide sanitation system on environmental contamination, infection risk, and well-being.To address potential confounding due to secular trends and/or weather-related events, we plan to include at least 10 comparison sites with existing improved sanitationinfrastructure and 10 sites with poor sanitation infrastructure not receiving the intervention during the study period.Bias will be reduced by defining enteric pathogen targets and the main statistical models prior to analysis.Although we will adjust for external trends such as temperature and rainfall, the design of an interrupted time series lacks a randomized control group, limiting the ability to fully isolate the intervention effect.Voluntary participation and required utility fees may lead to selection bias, and survey responses may be influenced by social desirability or courtesy bias. We aim to mitigate this through community engagement, confidentiality assurances, and validating survey responses with environmental testing.
美国农村卫生设施不足是面源污染的一个重要来源，可能对公众健康构成风险。我们建议进行一项中断时间序列分析，以衡量全镇范围的卫生设施扩展计划对病原体向环境释放的影响。这项工作有望为农村卫生改善在减少病原体释放以及支持公众健康和福祉方面的潜力提供有价值的见解。
我们将开展一项纵向基线研究，包括对缺乏适当卫生设施的家庭附近的关键肠道病原体和粪便指示菌进行定量测量。随着家庭接入服务整个社区的新污水系统，纵向家庭抽样将持续进行，直至转换完成。我们将纳入具有现有适当卫生设施的同期对照地点以及从未接受干预的地点，以监测研究期间病原体释放的长期趋势。
我们将使用适用于中断时间序列的时间序列回归分析，比较干预前后环境中可培养物的浓度。我们将把病原体测量与定量微生物风险评估相结合，以估计干预通过关键暴露途径对感染风险的潜在影响。一项前后关联调查将聚焦于接入该系统的家庭自我报告的生活质量指标。
在数据收集之前将获得知情同意，向参与者告知研究细节和风险。参与完全是自愿的，可识别的数据将与所有其他数据分开并安全存储。将为每个家庭提供其特定地点数据的摘要。经过去识别处理的结果将在公共论坛上与社区分享，并发表在同行评审期刊上。
本研究利用基于分子和培养的环境采样以及结构化的家庭和观察性调查，仔细评估社区范围的卫生系统对环境污染、感染风险和福祉的影响。为解决由于长期趋势和/或与天气相关的事件导致的潜在混杂问题，我们计划纳入至少10个具有现有改善卫生基础设施的对照地点以及10个在研究期间未接受干预且卫生基础设施较差的地点。通过在分析之前确定肠道病原体目标和主要统计模型来减少偏差。尽管我们将对温度和降雨等外部趋势进行调整，但中断时间序列的设计缺乏随机对照组，限制了完全分离干预效果的能力。自愿参与和所需的公用事业费用可能导致选择偏差，并且调查回复可能受到社会期望或礼貌偏差的影响。我们旨在通过社区参与、保密保证以及用环境检测验证调查回复来减轻这种情况。
