Quantitative analysis of SARS-CoV-2 RNA from wastewater solids in communities with low COVID-19 incidence and prevalence

Abstract

Highlights RT-ddPCR is more sensitive to inhibitors than RT-qPCR for primary clarified sludge Primary clarified sludge has elevated frequency of SARS-CoV-2 RNA detection Primary clarified sludge allows detection of RNA during low COVID-19 incidence PMMV normalization of RNA data reduces noise and increases precision PMMV normalization of RNA shows strongest correlation to epidemiological metrics

Catching a resurgence: Increase in SARS-CoV-2 viral RNA identified in wastewater 48 hours before COVID-19 clinical tests and 96 hours before hospitalizations

“…These findings are in agreement with reported observations from previous studies (D'Aoust et al, 2020;Nemudryi et al, 2020;Peccia et al, 2020). This study, as opposed to an earlier study in the same region (D'Aoust et al, 2020), demonstrates that strong correlations do in fact exist between viral RNA signal and the epidemiological metric of clinical daily new COVID-19 cases, as supported by several other studies (Hart and Halden, 2020;Michael-Kordatou et al, 2020;Trottier et al, 2020;Wu et al, 2020 Figure 2 a and e). Table 1).…”

“…This study demonstrates that due to the general stability of SARS-CoV-2 RNA measurements in PCS, this fraction of wastewater can reliably be utilized to predict rapid increases or resurgences in COVID-19 cases in the community at large (Alpaslan-Kocamemi et al, 2020;D'Aoust et al, 2020;Peccia et al, 2020), and the results strongly suggests that PCS can be utilized as part of sentinel-type wastewater based epidemiology endeavors at WRRFs.…”

“…The number of daily cases and percent positive cases was highest on July 19, with a 326% relative increase from the preceding 7-day period. Meanwhile, current hospitalized patient cases were at their highest on July 31-Aug 2 with a 168% increase compared to the week of July 13(Figure 2 a-d).PMMoV normalized SARS-CoV-2 viral copies, a metric outlined in an earlier publication(D'Aoust et al, 2020), normalizes SARS-CoV-2 viral copies by the number of copies of PMMoV in wastewater, and is effective due to the great temporal stability of PMMoV, as demonstrated inFigure 1, below.…”

“…Concentration of samples, extraction of nucleic acids and quantification of SARS-CoV-2 N1 and N2 gene regions were performed according to D'Aoust et al (2020). It has been previously observed that normalization of SARS-CoV-2 viral copies with pepper mild mottle virus (copies SARS-CoV-2/copies PMMoV) was used to normalize viral SARS-CoV-2 signal for variations in wastewater chemico-physical characteristics, plant flows, wastewater solids organic/inorganic ratio and PCR amplification (D'Aoust et al, 2020). Evaluation of viral recovery efficiency was also performed as per D'Aoust et al 2020; with the data in this study not being corrected for recovery efficiency.…”

Catching a resurgence: Increase in SARS-CoV-2 viral RNA identified in wastewater 48 h before COVID-19 clinical tests and 96 h before hospitalizations

“…WBE has been applied at wastewater resource recovery facilities (WRRFs), with early studies demonstrating that viral signal is detected from both influent and primary clarified sludge, with recent studies identifying that at WRRFs, primary clarified sludge may provide more sensitive measurements than in influent ( D'Aoust et al, 2021 ; Graham et al, 2020 ; Peccia et al, 2020 ). Additionally, recent studies outlined that viral particles of SARS-CoV-2 in wastewater could in fact be predominantly solid particle-bound ( Canadian Water Network (CWN), 2020 ; Graham et al, 2020 ) due to the virus' lipid bilayer, which causes it to be lipophilic ( Schoeman and Fielding, 2019 ).…”