An exploration of the relationship between wastewater viral signals and COVID-19 hospitalizations in Ottawa, Canada

K Ken Peng; Elizabeth M Renouf; Charmaine B Dean; X Joan Hu; Robert Delatolla; Douglas G Manuel

doi:10.1016/j.idm.2023.05.011

An exploration of the relationship between wastewater viral signals and COVID-19 hospitalizations in Ottawa, Canada

Infect Dis Model. 2023 Sep;8(3):617-631. doi: 10.1016/j.idm.2023.05.011. Epub 2023 Jun 7.

Authors

K Ken Peng¹, Elizabeth M Renouf², Charmaine B Dean², X Joan Hu¹, Robert Delatolla³, Douglas G Manuel^{4

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Affiliations

¹ Department of Statistics and Actuarial Science, Simon Fraser University, 8888 University Dr, Burnaby, V5A 1S6, BC, Canada.
² Department of Statistics and Actuarial Science, University of Waterloo, 200 University Ave W, Waterloo, N2L 3G1, ON, Canada.
³ Department of Civil Engineering, University of Ottawa, 75 Laurier Ave. E, Ottawa, K1N 6N5, ON, Canada.
⁴ The Ottawa Hospital Research Institute, 1053 Carling Ave, Ottawa, K1Y 4E9, ON, Canada.
⁵ Department of Family Medicine, University of Ottawa, 75 Laurier Ave. E, Ottawa, K1N 6N5, ON, Canada.
⁶ School of Epidemiology and Public Health, University of Ottawa, 75 Laurier Ave. E, Ottawa, K1N 6N5, ON, Canada.

Abstract

Monitoring of viral signal in wastewater is considered a useful tool for monitoring the burden of COVID-19, especially during times of limited availability in testing. Studies have shown that COVID-19 hospitalizations are highly correlated with wastewater viral signals and the increases in wastewater viral signals can provide an early warning for increasing hospital admissions. The association is likely nonlinear and time-varying. This project employs a distributed lag nonlinear model (DLNM) (Gasparrini et al., 2010) to study the nonlinear exposure-response delayed association of the COVID-19 hospitalizations and SARS-CoV-2 wastewater viral signals using relevant data from Ottawa, Canada. We consider up to a 15-day time lag from the average of SARS-CoV N1 and N2 gene concentrations to COVID-19 hospitalizations. The expected reduction in hospitalization is adjusted for vaccination efforts. A correlation analysis of the data verifies that COVID-19 hospitalizations are highly correlated with wastewater viral signals with a time-varying relationship. Our DLNM based analysis yields a reasonable estimate of COVID-19 hospitalizations and enhances our understanding of the association of COVID-19 hospitalizations with wastewater viral signals.

Keywords: COVID-19 vaccination effectiveness; Distributed lag nonlinear model; Time varying correlation; Wastewater surveillance.