COVID-19 patients can excrete viable SARS-CoV-2 virus via urine and faeces, which has raised concerns over the possibility of COVID-19 transmission via aerosolized contaminated water or via the faecal-oral route. These concerns are especially exacerbated in many low- and middle-income countries, where untreated sewage is frequently discharged to surface waters. SARS-CoV-2 RNA has been detected in river water (RW) and raw wastewater (WW) samples. However, little is known about SARS-CoV-2 viability in these environmental matrices. Determining the persistence of SARS-CoV-2 in water under different environmental conditions is of great importance for basic assumptions in quantitative microbial risk assessment (QMRA). In this study, the persistence of SARS-CoV-2 was assessed using plaque assays following spiking of RW and WW samples with infectious SARS-CoV-2 that was previously isolated from a COVID-19 patient. These assays were carried out on autoclaved RW and WW samples, filtered (0.22 µm) and unfiltered, at 4 °C and 24 °C. Linear and nonlinear regression models were adjusted to the data. The Weibull regression model achieved the lowest root mean square error (RMSE) and was hence chosen to estimate T₉₀ and T₉₉ (time required for 1 log and 2 log reductions, respectively). SARS-CoV-2 remained viable longer in filtered compared with unfiltered samples. RW and WW showed T₉₀ values of 1.9 and 1.2 day and T₉₉ values of 6.4 and 4.0 days, respectively. When samples were filtered through 0.22 µm pore size membranes, T₉₀ values increased to 3.3 and 1.5 days, and T₉₉ increased to 8.5 and 4.5 days, for RW and WW samples, respectively. Remarkable increases in SARS-CoV-2 persistence were observed in assays at 4 °C, which showed T₉₀ values of 7.7 and 5.5 days, and T₉₉ values of 18.7 and 17.5 days for RW and WW, respectively. These results highlight the variability of SARS-CoV-2 persistence in water and wastewater matrices and can be highly relevant to efforts aimed at quantifying water-related risks, which could be valuable for understanding and controlling the pandemic.

COVID-19 患者可以通过尿液和粪便排出活的 SARS-CoV-2 病毒，这引起了人们对 COVID-19 通过雾化污染水或通过粪口途径传播的可能性的担忧。这些担忧在许多低收入和中等收入国家尤为严重，在这些国家，未经处理的污水经常被排放到地表水中。已在河水 (RW) 和原废水 (WW) 样本中检测到 SARS-CoV-2 RNA。然而，人们对 SARS-CoV-2 在这些环境基质中的生存能力知之甚少。确定 SARS-CoV-2 在不同环境条件下在水中的持久性对于定量微生物风险评估 (QMRA) 的基本假设非常重要。在这项研究中，在 RW 和 WW 样本中加入先前从 COVID-19 患者身上分离出的传染性 SARS-CoV-2 后，使用斑块测定评估了 SARS-CoV-2 的持久性。这些测定是在 4 °C 和 24 °C 下对高压灭菌的 RW 和 WW 样品进行的，过滤（0.22 µm）和未过滤。根据数据调整线性和非线性回归模型。Weibull 回归模型实现了最低的均方根误差 (RMSE)，因此被选择用于估计 T₉₀和 T ₉₉（分别减少 1 个对数和 2 个对数所需的时间）。与未过滤的样本相比，SARS-CoV-2 在过滤后的存活时间更长。RW 和 WW 分别显示1.9 天和 1.2 天的T _{90值和 6.4 天和 4.0 天的 T 99}值。当样品通过孔径为 0.22 µm 的膜过滤时，RW 和 WW 样品的 T ₉₀值分别增加到 3.3 和 1.5 天，T ₉₉增加到 8.5 和 4.5 天。在 4 °C 的测定中观察到 SARS-CoV-2 持久性显着增加，显示 T ₉₀值为 7.7 和 5.5 天，T ₉₉RW 和 WW 的值分别为 18.7 天和 17.5 天。这些结果突出了 SARS-CoV-2 在水和废水基质中持久性的可变性，并且可能与旨在量化与水相关的风险的工作高度相关，这对于理解和控制大流行可能很有价值。