Nguyen Quoc Bao, Saingam Prakit, RedCorn Raymond, Carter John A, Jain Tanisha, Candry Pieter, Gattuso Meghan, Huang Meei-Li W, Greninger Alexander L, Meschke John Scott, Bryan Andrew, Winkler Mari K H
Department of Civil and Environmental Engineering, University of Washington, Seattle, Washington 98105, United States.
Seattle Public Utilities, Seattle, Washington 98124, United States.
ACS ES T Water. 2022 Jun 22;2(11):1964-1975. doi: 10.1021/acsestwater.2c00016. eCollection 2022 Nov 11.
Wastewater based epidemiology (WBE) has emerged as a tool to track the spread of SARS-CoV-2. However, sampling at wastewater treatment plants (WWTPs) cannot identify transmission hotspots within a city. Here, we sought to understand the diurnal variations (24 h) in SARS-CoV-2 RNA titers at the neighborhood level, using pump stations that serve vulnerable communities (e.g., essential workers, more diverse communities). Hourly composite samples were collected from wastewater pump stations located in (i) a residential area and (ii) a shopping district. In the residential area, SARS-CoV-2 RNA concentration (N1, N2, and E assays) varied by up to 42-fold within a 24 h period. The highest viral load was observed between 5 and 7 am, when viral RNA was not diluted by stormwater. Normalizing peak concentrations during this time window with nutrient concentrations (N and P) enabled correcting for rainfall to connect sewage to clinical cases reported in the sewershed. Data from the shopping district pump station were inconsistent, probably due to the fluctuation of customers shopping at the mall. This work indicates pump stations serving the residential area offer a narrow time period of high signal intensity that could improve the sensitivity of WBE, and tracer compounds (N, P concentration) can be used to normalize SARS-CoV-2 signals during rainfall.
基于废水的流行病学（WBE）已成为追踪严重急性呼吸综合征冠状病毒2（SARS-CoV-2）传播的一种工具。然而，在污水处理厂（WWTPs）进行采样无法识别城市内的传播热点。在此，我们试图利用为脆弱社区（如一线工作者、更多元化社区）服务的泵站，了解社区层面SARS-CoV-2 RNA滴度的昼夜变化（24小时）。从位于（i）一个居民区和（ii）一个购物区的废水泵站收集每小时的混合样本。在居民区，SARS-CoV-2 RNA浓度（N1、N2和E检测）在24小时内变化高达42倍。最高病毒载量出现在凌晨5点至7点之间，此时病毒RNA未被雨水稀释。用营养物浓度（N和P）对该时间窗口内的峰值浓度进行归一化处理，能够校正降雨影响，从而将污水与排水流域报告的临床病例联系起来。来自购物区泵站的数据不一致，可能是由于商场顾客流量的波动。这项工作表明，服务于居民区的泵站提供了一个信号强度高的狭窄时间段，这可以提高WBE的灵敏度，并且示踪化合物（N、P浓度）可用于在降雨期间对SARS-CoV-2信号进行归一化处理。
