Wastewater monitoring outperforms case numbers as a tool to track COVID-19 incidence dynamics when test positivity rates are high

•SARS-CoV-2 wastewater loads combined with shedding load distributions reveal COVID19 incidence dynamics.•Wastewater yields different dynamics than case numbers when test positivity rates are high.•Wastewater outperforms case numbers in identifying true outbreak peaks.•Wastewater can yield informati...

Full description

Saved in:
Bibliographic Details
Published in:Water research (Oxford) 2021-07, Vol.200, p.117252-117252, Article 117252
Main Authors: Fernandez-Cassi, Xavier, Scheidegger, Andreas, Bänziger, Carola, Cariti, Federica, Tuñas Corzon, Alex, Ganesanandamoorthy, Pravin, Lemaitre, Joseph C., Ort, Christoph, Julian, Timothy R., Kohn, Tamar
Format: Article
Language:English
Subjects:
Compartmental model
COVID-19
Disease dynamics
Humans
Incidence
New infections
RNA, Viral
SARS-CoV-2
Sewage
Shedding load distribution
Switzerland - epidemiology
Wastewater
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:•SARS-CoV-2 wastewater loads combined with shedding load distributions reveal COVID19 incidence dynamics.•Wastewater yields different dynamics than case numbers when test positivity rates are high.•Wastewater outperforms case numbers in identifying true outbreak peaks.•Wastewater can yield information on pandemic trajectory that case numbers cannot. Wastewater-based epidemiology (WBE) has been shown to coincide with, or anticipate, confirmed COVID-19 case numbers. During periods with high test positivity rates, however, case numbers may be underreported, whereas wastewater does not suffer from this limitation. Here we investigated how the dynamics of new COVID-19 infections estimated based on wastewater monitoring or confirmed cases compare to true COVID-19 incidence dynamics. We focused on the first pandemic wave in Switzerland (February to April, 2020), when test positivity ranged up to 26%. SARS-CoV-2 RNA loads were determined 2–4 times per week in three Swiss wastewater treatment plants (Lugano, Lausanne and Zurich). Wastewater and case data were combined with a shedding load distribution and an infection-to-case confirmation delay distribution, respectively, to estimate infection incidence dynamics. Finally, the estimates were compared to reference incidence dynamics determined by a validated compartmental model. Incidence dynamics estimated based on wastewater data were found to better track the timing and shape of the reference infection peak compared to estimates based on confirmed cases. In contrast, case confirmations provided a better estimate of the subsequent decline in infections. Under a regime of high-test positivity rates, WBE thus provides critical information that is complementary to clinical data to monitor the pandemic trajectory. [Display omitted]
ISSN:0043-1354
1879-2448
DOI:10.1016/j.watres.2021.117252