Abstract：
Wastewater-based epidemiology (WBE) is a valuable disease surveillance tool. However, little is known on how factors such as transportation, storage, and wastewater characteristics influence the accuracy of the quantification methods. Hence, this study investigated the impact of storage temperatures and physicochemical characteristics of wastewater on SARS-CoV-2 and influenza A stability using droplet digital PCR. Additionally, strategies to enhance viral recovery were explored. Municipal influent wastewater stored between ±25 and -80 °C was assessed for a period of 84 days to determine viral degradation. Degradation up to 94.1% of influenza A and SARS-CoV-2 was observed in all samples with the highest at ±25 °C. Viral degradation was correlated to the changes in wastewater physicochemical characteristics. The low degradation observed of SARS-CoV-2 in the spiked pellets were indicative of viral adhesion to wastewater solids, which correlated with changes in pH. Ultrasonication frequencies ranging from 4 to 16 kHz, increased SARS-CoV-2 concentrations in the supernatant between 3.30 and 35.65%, indicating viral RNA attachment to wastewater solids. These results highlight the importance of additional pretreatment methods for maximizing RNA recovery from wastewater samples. Based on these findings, it was deduced that wastewater preservation studies are essential, and pretreatment should be included in the WBE methodology.
摘要：
基于废水的流行病学（WBE）是一种有价值的疾病监测工具。然而,对运输等因素知之甚少，storage,和废水特性影响定量方法的准确性。因此，本研究使用液滴数字PCR研究了废水的储存温度和理化特性对SARS-CoV-2和甲型流感稳定性的影响。此外,探讨了增强病毒恢复的策略。评估储存在±25至-80°C之间的市政进水废水84天的时间以确定病毒降解。在所有样品中观察到高达94.1%的甲型流感和SARS-CoV-2的降解,在±25°C最高。病毒降解与废水理化特性的变化相关。在加标颗粒中观察到的SARS-CoV-2的低降解表明病毒对废水固体的粘附，这与pH值的变化有关。超声频率范围从4到16kHz，上清液中SARS-CoV-2的浓度增加了3.30％至35.65％，表明病毒RNA附着于废水固体。这些结果突出了额外的预处理方法对于从废水样品中最大化RNA回收的重要性。基于这些发现,推断废水保存研究是必不可少的，预处理应包括在WBE方法中。
