Fisher’s exact pairwise tests.

Soil-transmitted helminths (STH) are one of the most prevalent enteric infections world-wide. To control STH-related morbidity, the World Health Organization recommends targeted deworming and improvements in water, sanitation and hygiene. Current surveillance strategies for STH focus on identifying and quantifying eggs in stool samples via microscopy, which exhibits poor specificity and sensitivity, especially in settings with low-intensity infections. Wastewater-based epidemiology is a surveillance tool used to monitor pathogen circulation and could replace stool-based approaches for STH detection. However, sampling strategies for settings lacking networked sanitation outside large urban settlements are not well developed. Here, we report evaluation of sampling strategies for soil and wastewater STH surveillance in rural and peri-urban settings without networked sanitation. We used multi-parallel qPCR assays to detect STH DNA in soil collected from high foot-traffic locations and three types of wastewater samples (passive Moore swabs, grab samples, and sediment from drainage ditches) in Comé, Benin and Timiri and Jawadhu Hills in Tamil Nadu, India. We detected STH in soil (India = 32/95, Benin = 39/121) and wastewater (India = 24/60, Benin = 8/64) with a detection frequency across all sample types of 36% in India and 25% in Benin. We evaluated which sample locations and types allowed for more sensitive detection of STH DNA and determined that STH prevalence varied by sample site but did not vary significantly within a given sample site location (e.g., samples collected from multiple locations within one market). Further, we determined that wastewater sediment samples outperformed grab and Moore swab sample types for STH detection. Finally, we expanded our methods to include detection of other enteric pathogens using multiplexed qPCR for wastewater samples. Our results establish sampling strategies for environmental and wastewater surveillance of a wide range of enteric pathogens in settings without networked sanitation.土源性蠕虫（Soil-transmitted helminths, STH）是全球范围内最常见的肠道感染之一。为控制STH相关发病负担，世界卫生组织（World Health Organization）推荐实施靶向驱虫，并改善水、环境卫生与个人卫生。当前针对STH的监测策略主要通过显微镜技术识别并定量粪便样本中的虫卵，但该方法特异性与敏感性欠佳，尤其在感染强度较低的环境中。基于废水的流行病学（Wastewater-based epidemiology, WBE）是一种用于监测病原体传播的监测手段，有望替代粪便检测方法用于STH的检测。然而，针对大型城镇定居点以外缺乏联网卫生设施的地区的采样策略尚未得到充分研究与完善。本研究针对无联网卫生设施的农村及城郊环境下的土壤与废水STH监测采样策略进行了系统评估。我们在贝宁科梅以及印度泰米尔纳德邦的蒂米里与贾瓦杜山开展采样，采集了高人流区域的土壤样本与三类废水样本，包括被动穆尔拭子（Moore swabs）、瞬时样本以及排水沟沉积物样本，并采用多平行定量聚合酶链反应（quantitative PCR, qPCR）检测其中的STH DNA。我们在土壤样本（印度：32/95，贝宁：39/121）与废水样本（印度：24/60，贝宁：8/64）中均检出STH，所有样本类型的总检出率在印度为36%，在贝宁为25%。我们评估了不同采样点位与样本类型对STH DNA的检测敏感性，结果显示STH检出率存在位点间差异，但在同一采样位点内无显著差异（例如同一市场内多个点位采集的样本）。此外，我们发现用于STH检测时，废水沉积物样本的检测性能优于瞬时样本与穆尔拭子样本。最后，我们将研究方法拓展至采用多重qPCR检测废水中的其他肠道病原体。本研究结果为无联网卫生设施环境下多类肠道病原体的环境与废水监测建立了标准化采样策略。