SARS-CoV-2 RNA concentrations in primary municipal sewage sludge as a leading indicator of COVID-19 outbreak dynamics

Abstract

We report a time course of SARS-CoV-2 RNA concentrations in primary sewage sludge during the Spring COVID-19 outbreak in a northeastern U.S. metropolitan area. SARS-CoV-2 RNA was detected in all environmental samples, and when adjusted for the time lag, the virus RNA concentrations tracked the COVID-19 epidemiological curve. SARS-CoV-2 RNA concentrations were a leading indicator of community infection ahead of compiled COVID-19 testing data and local hospital admissions. Decisions to implement or relax public health measures and restrictions require timely information on outbreak dynamics in a community.

Correlation of SARS-CoV-2 RNA in wastewater with COVID-19 disease burden in sewersheds

“…These results suggest that the increase in case counts may occur concurrently with or even precede the increase in SARS-CoV-2 RNA in wastewater, while the decline in SARS-CoV-2 RNA in wastewater may lag the decline in case counts. This temporal variation in RNA in wastewater versus case counts has been suggested by others 24,25,28,34 . Further, the long term shedding of the SARS-CoV-2 after negative nasopharyngeal swabs may account for the detection of RNA in wastewater after the decline in case counts 35 .…”

“…In this study, we evaluated the effect of incubation of SARS-CoV-2 RNA containing wastewater at different temperatures on the loss of RNA over time ( Overall, more viral SARS-CoV-2 RNA was detectable in the liquid phase (91 ± 12% by mass) of the wastewater influent compared to the RNA sorbed on the solids (9 ± 12% by mass). Others have reported the detection of the SARS-CoV-2 RNA on activated sludge in treatment plants 34,41 . Given that most wastewater is near neutral pH and the SARS-CoV-2 spike proteins have estimated isoelectric points around 5.4 and 5.3 42 , the virion positive core is likely surrounded by negatively charged envelopes and spikes in these wastewaters.…”

Highly predictive regression model of active cases of COVID-19 in a population by screening wastewater viral load

“…Similarly, there has been no evidence of contagion through wastewater, which might reflect SARS-CoV-2's instability in water and its sensitivity to disinfectants 9,[29][30][31][32][33][34] . Viral RNA can, nonetheless, be found in wastewater 33 , which has made monitoring of viral RNA load in sewage a promising tool for the epidemiological tracking of the pandemic [35][36][37][38][39][40] .…”

“…Another study in a region of Spain with the lowest prevalence of COVID-19, detected the virus in wastewater before the first COVID-19 cases were reported 37 . A study from Yale University measured the concentration of SARS-CoV-2 RNA in sewage sludge and found that viral RNA concentrations were highest 3 days before peak hospital admissions of COVID-19 cases, and 7 days before peak community COVID-19 cases 40 . Also, Balboa et al, 49 confirmed the presence of SARS-CoV-2 in sludge.…”

Microbicidal actives with virucidal efficacy against SARS-CoV-2 and other beta- and alpha-coronaviruses: implications for future emerging coronaviruses and other enveloped viruses

“…The nding of SARS-CoV-2 RNA in untreated wastewater 37 and sewage 38 , is suggestive of, but certainly not proof of, the possibility for survival of infectious virus within these human waste streams reviewed in 35,39,40 . Unfortunately, there are, to our knowledge, no data on the detection or persistence of infectious SARS-CoV-2 in wastewater, and this topic, therefore, remains a knowledge gap 35,39,40 .…”