Soil epidemiology: a new tool for environmental surveillance of soil-transmitted helminth infections in endemic settings.

土壤流行病学：流行地区土源性蠕虫感染环境监测的新工具。

• 批准号: 10450113
• 负责人: Sitara Swarna Rao Ajjampur
• 金额: $ 67万
• 依托单位: UNIVERSITY OF CALIFORNIA BERKELEY
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-07-13 至 2026-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10450113
• 关键词: Adherence; Affect; Area; Biological Assay; COVID-19 pandemic; Collection; Communities; Country; DNA; Data; Detection; Effectiveness; Epidemiology; Evaluation; Feces; Foundations; Geography; Helminths; Home; Household; Human; Human Activities; India; Individual; Infection; Infrastructure; Intervention; Intestinal parasite; Intestines; Laboratory Study; Lead; Location; Logistics; Measurement; Methods; Modeling; Molecular; Molecular Analysis; Monitor; Morbidity - disease rate; Only Child; Parents; Persons; Pharmaceutical Preparations; Population; Population Density; Populations at Risk; Prevalence; Program Effectiveness; Randomized Controlled Trials; Recrudescences; Resources; Sampling; Sanitation; School-Age Population; Schools; Site; Soil; Source; Study models; Surveillance Methods; Temperature; Testing; Time; Water; Water Supply; base; burden of illness; cost; cost effective; diagnostic strategy; egg; enteric pathogen; field study; helminth infection; improved; infection rate; infection risk; novel; predictive modeling; prevent; programs; soil sampling; standard of care; stool sample; success; tool; transmission process

PROJECT SUMMARY Soil-transmitted helminth (STH) infections (intestinal worms) affect 1.5 billion individuals globally. Recent evidence from trials and modeling studies suggests that community-wide mass drug administration (cMDA) of deworming medication with sufficient coverage and adherence can eliminate STH transmission. However, in settings with ongoing environmental transmission and low coverage of networked sanitation, persistent environmental reservoirs of STH eggs result in high reinfection rates, and hinder progress towards elimination. STH control programs use human stool-based methods to assess STH prevalence and intensity in endemic settings. However, individual stool sampling is expensive and logistically difficult, particularly when human infection prevalence is low. If collecting and analyzing soil from locations in communities with high human activity (e.g. home entrances, water collection points, schools) were established to be equally or more sensitive than human stool diagnostics, this approach may represent a less invasive and more cost-effective surveillance tool for MDA program monitoring and evaluation. This study will leverage a multi-country cluster-randomized controlled trial delivering three-years of biannual cMDA in Benin and India (DeWorm3). The trial will collect and analyze by qPCR, human stool samples 24 months (n=80,000 in total) after the final round of cMDA, which will yield highly accurate human STH infection prevalence estimates in the study areas. Through extensive laboratory studies and field testing in India and Benin, our team has developed a sensitive and specific molecular method for detecting STH environmental DNA (eDNA) in large volumes of soil. We will nest soil sampling within the trial at the same time point as human stool collection and one year later with the specific aims to: 1) Quantify the effect of a biannual cMDA intervention on the soil STH reservoir; 2) Determine whether soil STH eDNA levels can predict community-level human STH infection prevalence; and 3) Develop the optimal soil sampling strategy and compare costs to human stool-based surveillance. Pairing soil STH eDNA assessments with human infection prevalence data already being collected by the DeWorm3 trial is a unique and time sensitive opportunity to validate and test the utility of environmental STH surveillance. Our findings will also contribute to understanding the conditions under which MDA program integration with improved sanitation interventions is needed for achieving sustained reductions in STH infection prevalence.

项目概要 土源性蠕虫 (STH) 感染（肠道蠕虫）影响着 15 亿人 全球。来自试验和模型研究的最新证据表明，社区范围内的群众 具有足够覆盖率和依从性的驱虫药物管理（cMDA） 可以消除STH传输。然而，在环境传播持续存在的环境中 网络化卫生设施覆盖率低，STH虫卵的环境水库持续存在 导致高再感染率，并阻碍消除进程。 STH 控制计划使用基于人体粪便的方法来评估 STH 患病率和 流行环境中的强度。然而，单独的粪便采样成本高昂且不方便 很难，特别是当人类感染率较低时。如果收集并分析来自 人类活动频繁的社区位置（例如住宅入口、集水点、 学校）被确定为与人类粪便诊断同等或更敏感，这 方法可能代表一种侵入性较小且更具成本效益的 MDA 监测工具 计划监测和评估。 这项研究将利用多国集群随机对照试验进行 在贝宁和印度开展了为期三年、一年两次的 CMDA (DeWorm3)。试验将收集并分析 通过 qPCR，最后一轮 cMDA 后 24 个月（总共 n=80,000）的人类粪便样本， 这将产生研究区域内高度准确的人类 STH 感染流行率估计。 通过在印度和贝宁进行广泛的实验室研究和现场测试，我们的团队已经 开发了一种灵敏且特异的分子方法来检测 STH 环境 DNA (eDNA) 存在于大量土壤中。我们将在试验中的同一时间点进行土壤采样 作为人类粪便收集，一年后，其具体目标是：1）量化 每年两次 cMDA 对土壤 STH 水库进行干预； 2) 判断土壤STH eDNA是否存在 水平可以预测社区水平人类 STH 感染流行率； 3) 制定最优方案 土壤采样策略并与基于人类粪便的监测进行成本比较。 已将土壤 STH eDNA 评估与人类感染流行率数据配对 DeWorm3 试验收集的数据是一个独特且时间敏感的机会来验证和 测试环境 STH 监测的效用。我们的研究结果也将有助于 了解 MDA 计划与改善卫生设施相结合的条件 需要采取干预措施来持续降低 STH 感染率。