SARS-CoV-2 Titers in Wastewater Are Higher than Expected from Clinically Confirmed Cases
By Fuqing Wu, Jianbo Zhang, A. Xiao, Xiaoqiong Gu, W. Lee, F. Armas, Kathryn M. Kauffman, W. Hanage, M. Matus, N. Ghaeli and 9 more. mSystems, 2020
748 citations recorded by the source corpus.
Wastewater-based surveillance is a promising approach for proactive outbreak monitoring. SARS-CoV-2 is shed in stool early in the clinical course and infects a large asymptomatic population, making it an ideal target for wastewater-based monitoring. In this study, we develop a laboratory protocol to quantify viral titers in raw sewage via qPCR analysis and validate results with sequencing analysis. Our results suggest that the number of positive cases estimated from wastewater viral titers is orders of magnitude greater than the number of confirmed clinical cases and therefore may significantly impact efforts to understand the case fatality rate and progression of disease. These data may help inform decisions surrounding the advancement or scale-back of social distancing and quarantine efforts based on dynamic wastewater catchment-level estimations of prevalence. ABSTRACT Wastewater surveillance represents a complementary approach to clinical surveillance to measure the presence and prevalence of emerging infectious diseases like the novel coronavirus SARS-CoV-2. This innovative data source can improve the precision of epidemiological modeling to understand the penetrance of SARS-CoV-2 in specific vulnerable communities. Here, we tested wastewater collected at a major urban treatment facility in Massachusetts and detected SARS-CoV-2 RNA from the N gene at significant titers (57 to 303 copies per ml of sewage) in the period from 18 to 25 March 2020 using RT-qPCR. We validated detection of SARS-CoV-2 by Sanger sequencing the PCR product from the S gene. Viral titers observed were significantly higher than expected based on clinically confirmed cases in Massachusetts as of 25 March. Our approach is scalable and may be useful in modeling the SARS-CoV-2 pandemic and future outbreaks. IMPORTANCE Wastewater-based surveillance is a promising approach for proactive outbreak monitoring. SARS-CoV-2 is shed in stool early in the clinical course and infects a large asymptomatic population, making it an ideal target for wastewater-based monitoring. In this study, we develop a laboratory protocol to quantify viral titers in raw sewage via qPCR analysis and validate results with sequencing analysis. Our results suggest that the number of positive cases estimated from wastewater viral titers is orders of magnitude greater than the number of confirmed clinical cases and therefore may significantly impact efforts to understand the case fatality rate and progression of disease. These data may help inform decisions surrounding the advancement or scale-back of social distancing and quarantine efforts based on dynamic wastewater catchment-level estimations of prevalence.
Subfields: Infectious Diseases, Radiology, Nuclear Medicine and Imaging
View Paper: https://www.semanticscholar.org/paper/2ff94299d9d395732c2e6bd41fb3be3c0031519c
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In Infectious Diseases
Citations in the corpus
- Computational analysis of SARS-CoV-2/COVID-19 surveillance by wastewater-based epidemiology locally and globally: Feasibility, economy, opportunities and challenges (2020, background): “Previous studies reporting on the use of WBE for detecting SARS-CoV-2 had very limited surveillance durations (Ahmed et al., 2020; Lodder and de Roda Husman, 2020; Medema et al., 2020; Wu et al., 2020); rendering temperature a marginal factor overall.”
- SARS-CoV-2 in wastewater: State of the knowledge and research needs (2020, positive): “…to perform a virus concentration step(s) prior to subsequent detection of SARS-CoV-2, even in untreated wastewater, as conducted previously (Ahmed et al., 2020; Lodder and de Roda Husman, 2020; Medema et al., 2020; Nemudryi et al., 2020; F. Wu et al., 2020b; Wurtzer et al., 2020) (Table 2).”
- First detection of SARS-CoV-2 in untreated wastewaters in Italy (2020, neutral): “Furthermore, preliminary studies have reported the detection of SARS-CoV-2 RNA in wastewater in The Netherlands (Medema et al., 2020), France (Wurtzer et al., 2020), USA (Wu et al., 2020), and Australia (Ahmed et al., 2020).”