了解严重急性呼吸系统综合症冠状病毒2(SARS-CoV-2)在废水和环境水域中的衰减特征对于多种应用非常重要,包括评估与处理废水样品相关的暴露风险。与废水污染的环境水域中的娱乐相关的公共卫生风险,以及对废水流行病学(WBE)结果的更好理解和解释。我们评估了在代表季节性波动的温度条件下,废水和环境水中感染性SARS-CoV-2和病毒RNA的衰减率。将传染性病毒接种在高压灭菌的主要废水中,最终脱氯废水,湖水,和海水,终浓度为每毫升6.26±0.07log10斑块形成单位。每个悬浮液在4°孵育,25°,37°C样本最初是按小时收集的,然后大约每隔一天15天。通过使用VeroE6细胞系的噬斑测定分析所有样品的感染性病毒。使用美国CDC的N1和N2逆转录酶定量聚合酶链反应(RT-qPCR)测定对病毒基因拷贝水平进行定量。与病毒RNA相比,感染性病毒的腐烂速度明显更快(p≤0.0214),无论孵育条件如何,在研究期间都会持续存在。与其他类型的水相比,初级处理废水的初始损失(播种后15分钟内)以及传染性SARS-CoV-2的腐烂明显更快(p≤0.0387),但是直到第15天,病毒RNA才在该基质中明显降解。总的来说,温度是衰变最重要的驱动因素,24小时后,在37°C下在任何类型的水中均未检测到传染性SARS-CoV-2。此外,与CDCN1相比,CDCN2基因检测目标在升高的温度下显著更快地衰减(p≤0.0174),这对于WBE方法的RT-qPCR检测选择具有重要意义.
Understanding the decay characteristics of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in
wastewater and ambient waters is important for multiple applications including assessment of risk of exposure associated with handling wastewater samples, public health risk associated with recreation in
wastewater polluted ambient waters and better understanding and interpretation of
wastewater-based epidemiology (WBE) results. We evaluated the decay rates of infectious SARS-CoV-2 and viral RNA in
wastewater and ambient waters under temperature regimes representative of seasonal fluctuations. Infectious virus was seeded in autoclaved primary
wastewater effluent, final dechlorinated
wastewater effluent, lake water, and marine water at a final concentration of 6.26 ± 0.07 log10 plaque forming units per milliliter. Each suspension was incubated at either 4°, 25°, and 37 °C. Samples were initially collected on an hourly basis, then approximately every other day for 15 days. All samples were analyzed for infectious virus via a plaque assay using the Vero E6 cell line, and viral gene copy levels were quantified with the US CDC\'s N1 and N2 reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) assays. The infectious virus decayed significantly faster (p ≤ 0.0214) compared to viral RNA, which persisted for the duration of the study irrespective of the incubation conditions. The initial loss (within 15 min of seeding) as well as decay of infectious SARS-CoV-2 was significantly faster (p ≤ 0.0387) in primary treated wastewater compared to other water types, but viral RNA did not degrade appreciably in this matrix until day 15. Overall, temperature was the most important driver of decay, and after 24 h, no infectious SARS-CoV-2 was detected at 37 °C in any water type. Moreover, the CDC N2 gene assay target decayed significantly (p ≤ 0.0174) faster at elevated temperatures compared to CDC N1, which has important implications for RT-qPCR assay selection for WBE approach.