SARS-COV-2 VIRAL LOAD IN GOIÂNIA WASTEWATER: WASTEWATER-BASED EPIDEMIOLOGY FOR A COVID-19 EARLY WARNING SYSTEM

COVID-19 is currently the most critical disease in the world. Thus, several tools have been used in the last two years to contain the spread of SARS-CoV-2. In this perspective, Wastewater-Based Epidemiology (WBE) provides valuable data by including symptomatic, pre-symptomatic, and asymptomatic individuals and anticipating clinical cases. For 37 weeks, the SARS-CoV-2 viral load was monitored in sanitary sewage samples from Goiânia-Brazil. Through pre-concentration, extraction, and purification of viral RNA, followed by RT-qPCR, it was detected in 83.78% (31/37) of the weeks the presence of fragments of the genetic material SARS-CoV-2 with viral loads ranging from 105 to 108 genome copies L-1. The viral load in the wastewater samples was related to the clinical data of the municipality, demonstrating its ability to promote an Early Warning System (EWS). In early 2022, it was possible to predict the increase in clinical cases 3 weeks in advance and issue an alert note to the health authorities. Prevalence estimates ranged from 0.003 to 0.5% and showed good agreement with observed values. Thus, monitoring effluents become another essential tool that can help combat the pandemic’s advance, especially in countries with scarce resources.COVID-19是当前全球最严峻的传染病。近两年来，全球已采用多种工具遏制严重急性呼吸综合征冠状病毒2型（SARS-CoV-2）的传播。在此背景下，基于污水的流行病学（Wastewater-Based Epidemiology）可覆盖有症状、症状前驱期及无症状感染者，还能提前预警临床病例的出现，因此可提供极具价值的监测数据。研究团队对巴西戈亚尼亚市的生活污水样本开展了为期37周的SARS-CoV-2病毒载量监测。通过对病毒RNA进行预浓缩、提取与纯化，结合反转录定量聚合酶链反应（RT-qPCR）检测，研究在83.78%（31/37）的采样周中均检出SARS-CoV-2的遗传物质片段，病毒载量范围为10^5至10^8 基因组拷贝·升⁻¹。污水样本中的病毒载量与该市的临床监测数据呈现显著相关性，证实其可用于构建早期预警系统（Early Warning System，简称EWS）。2022年初，该监测体系可提前3周预测临床病例数的增长，并向卫生主管部门发布预警通知。研究估算的人群感染率范围为0.003%至0.5%，与实际观测值的吻合度良好。综上，污水监测可成为助力抗击新冠疫情大流行的又一关键工具，尤其适用于医疗资源相对匮乏的国家。