Department of Environmental Science and Management, North South University, Bashundhara, Dhaka, 1229, Bangladesh.
COVID-19 Diagnostic Laboratory, Department of Microbiology, Noakhali Science and Technology University, Noakhali, 3814, Bangladesh.
Environ Pollut. 2022 Oct 15;311:119679. doi: 10.1016/j.envpol.2022.119679. Epub 2022 Jun 23.
Wastewater-based epidemiology (WBE) has emerged as a valuable approach for forecasting disease outbreaks in developed countries with a centralized sewage infrastructure. On the other hand, due to the absence of well-defined and systematic sewage networks, WBE is challenging to implement in developing countries like Bangladesh where most people live in rural areas. Identification of appropriate locations for rural Hotspot Based Sampling (HBS) and urban Drain Based Sampling (DBS) are critical to enable WBE based monitoring system. We investigated the best sampling locations from both urban and rural areas in Bangladesh after evaluating the sanitation infrastructure for forecasting COVID-19 prevalence. A total of 168 wastewater samples were collected from 14 districts of Bangladesh during each of the two peak pandemic seasons. RT-qPCR commercial kits were used to target ORF1ab and N genes. The presence of SARS-CoV-2 genetic materials was found in 98% (165/168) and 95% (160/168) wastewater samples in the first and second round sampling, respectively. Although wastewater effluents from both the marketplace and isolation center drains were found with the highest amount of genetic materials according to the mixed model, quantifiable SARS-CoV-2 RNAs were also identified in the other four sampling sites. Hence, wastewater samples of the marketplace in rural areas and isolation centers in urban areas can be considered the appropriate sampling sites to detect contagion hotspots. This is the first complete study to detect SARS-CoV-2 genetic components in wastewater samples collected from rural and urban areas for monitoring the COVID-19 pandemic. The results based on the study revealed a correlation between viral copy numbers in wastewater samples and SARS-CoV-2 positive cases reported by the Directorate General of Health Services (DGHS) as part of the national surveillance program for COVID-19 prevention. The findings of this study will help in setting strategies and guidelines for the selection of appropriate sampling sites, which will facilitate in development of comprehensive wastewater-based epidemiological systems for surveillance of rural and urban areas of low-income countries with inadequate sewage infrastructure.
基于污水的流行病学（WBE）已成为一种有价值的方法，可用于预测具有集中式污水基础设施的发达国家的疾病爆发。另一方面，由于缺乏明确和系统的污水管网，WBE 在孟加拉国等发展中国家实施具有挑战性，孟加拉国大多数人居住在农村地区。确定农村热点采样（HBS）和城市排水采样（DBS）的合适地点对于启用基于污水的监测系统至关重要。我们在评估卫生基础设施以预测 COVID-19 流行率之后，从孟加拉国的城市和农村地区中确定了最佳采样地点。在两个高峰期大流行季节中，从孟加拉国的 14 个地区共收集了 168 个污水样本。使用 RT-qPCR 商业试剂盒针对 ORF1ab 和 N 基因进行检测。在第一轮和第二轮采样中，分别在 168 个污水样本中的 98%（165/168）和 95%（160/168）中发现了 SARS-CoV-2 遗传物质。尽管根据混合模型，从市场和隔离中心污水中发现了最高量的遗传物质，但在其他四个采样点也鉴定出了可量化的 SARS-CoV-2 RNA。因此，可以考虑农村地区市场的污水和城市地区隔离中心的污水作为检测传染热点的合适采样地点。这是首次在从农村和城市地区采集的污水样本中检测 SARS-CoV-2 遗传成分的完整研究，用于监测 COVID-19 大流行。该研究结果基于卫生服务总局（DGHS）作为 COVID-19 预防国家监测计划的一部分报告的污水样本中病毒拷贝数与 SARS-CoV-2 阳性病例之间的相关性。本研究的结果将有助于制定策略和指南，以选择合适的采样地点，这将有助于为缺乏污水基础设施的低收入国家的农村和城市地区建立全面的基于污水的流行病学监测系统。
