Modeling the number of people infected with SARS-COV-2 from wastewater viral load in Northwest Spain

Juan A Vallejo; Noelia Trigo-Tasende; Soraya Rumbo-Feal; Kelly Conde-Pérez; Ángel López-Oriona; Inés Barbeito; Manuel Vaamonde; Javier Tarrío-Saavedra; Rubén Reif; Susana Ladra; Bruno K Rodiño-Janeiro; Mohammed Nasser-Ali; Ángeles Cid; María Veiga; Antón Acevedo; Carlos Lamora; Germán Bou; Ricardo Cao; Margarita Poza

doi:10.1016/j.scitotenv.2021.152334

Modeling the number of people infected with SARS-COV-2 from wastewater viral load in Northwest Spain

Sci Total Environ. 2022 Mar 10:811:152334. doi: 10.1016/j.scitotenv.2021.152334. Epub 2021 Dec 16.

Authors

Juan A Vallejo¹, Noelia Trigo-Tasende¹, Soraya Rumbo-Feal¹, Kelly Conde-Pérez¹, Ángel López-Oriona², Inés Barbeito², Manuel Vaamonde², Javier Tarrío-Saavedra³, Rubén Reif⁴, Susana Ladra⁵, Bruno K Rodiño-Janeiro⁶, Mohammed Nasser-Ali¹, Ángeles Cid⁷, María Veiga⁸, Antón Acevedo⁹, Carlos Lamora¹⁰, Germán Bou¹, Ricardo Cao¹¹, Margarita Poza¹²

Affiliations

¹ Microbiology Research Group, University Hospital Complex (CHUAC), Institute of Biomedical Research (INIBIC), University of A Coruña (UDC), Servicio de Microbiología, 3(a) planta, Edificio Sur, Hospital Universitario, As Xubias, 15006, A Coruña, CIBER de enfermedades infecciosas, Spain.
² Research Group MODES, Research Center for Information and Communication Technologies (CITIC), University of A Coruña (UDC), Facultade de Informática, Campus de Elviña, 15071 A Coruña, Spain.
³ Research Group MODES, Research Center for Information and Communication Technologies (CITIC), University of A Coruña (UDC), Facultade de Informática, Campus de Elviña, 15071 A Coruña, Spain. Electronic address: javier.tarrio@udc.es.
⁴ Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CiQUS), Universidade de Santiago de Compostela, 15782-Santiago de Compostela, Spain.
⁵ Database Laboratory, Research Center for Information and Communication Technologies (CITIC), University of A Coruña (UDC), Campus de Elviña, 15008 A Coruña, Spain.
⁶ BFlow, Campus Vida, Universidade Santiago de Compostela and Instituto de Investigatión Sanitaria de Santiago de Compostela, Edificio Emprendia, Avenida do Mestre Mateo, 2, 15706 Santiago de Compostela, A Coruña, Spain.
⁷ Department of Biology, University of A Coruña (UDC), Campus da Zapateira, 15071 A Coruña, Spain; Advanced Scientific Research Center (CICA), University of A Coruña (UDC), As Carballeiras, Campus de Elviña 15071 A Coruña, Spain.
⁸ Advanced Scientific Research Center (CICA), University of A Coruña (UDC), As Carballeiras, Campus de Elviña 15071 A Coruña, Spain.
⁹ General Directorate of Social Health Care, Xunta de Galicia, Edificios Administrativos, San Caetano s/n, 15781 Santiago de Compostela, A Coruña, Spain.
¹⁰ Public Wastewater Treatment Plant Company EDAR Bens, S.A., Lugar de Bens, 15010 A Coruña, Spain.
¹¹ Research Group MODES, Research Center for Information and Communication Technologies (CITIC), University of A Coruña (UDC), Facultade de Informática, Campus de Elviña, 15071 A Coruña, Spain; Technological Institute for Industrial Mathematics (ITMATI), Universities of A Coruña (UDC), Santiago de Compostela (USC) and Vigo (UVIGO), Campus Vida, Rúa de Constantino Candeira, 15705 Santiago de Compostela, Spain. Electronic address: rcao@udc.es.
¹² Microbiology Research Group, University Hospital Complex (CHUAC), Institute of Biomedical Research (INIBIC), University of A Coruña (UDC), Servicio de Microbiología, 3(a) planta, Edificio Sur, Hospital Universitario, As Xubias, 15006, A Coruña, CIBER de enfermedades infecciosas, Spain; Department of Biology, University of A Coruña (UDC), Campus da Zapateira, 15071 A Coruña, Spain; Advanced Scientific Research Center (CICA), University of A Coruña (UDC), As Carballeiras, Campus de Elviña 15071 A Coruña, Spain. Electronic address: margarita.poza.dominguez@sergas.es.

Abstract

The quantification of the SARS-CoV-2 RNA load in wastewater has emerged as a useful tool to monitor COVID-19 outbreaks in the community. This approach was implemented in the metropolitan area of A Coruña (NW Spain), where wastewater from a treatment plant was analyzed to track the epidemic dynamics in a population of 369,098 inhabitants. Viral load detected in the wastewater and the epidemiological data from A Coruña health system served as main sources for statistical models developing. Regression models described here allowed us to estimate the number of infected people (R² = 0.9), including symptomatic and asymptomatic individuals. These models have helped to understand the real magnitude of the epidemic in a population at any given time and have been used as an effective early warning tool for predicting outbreaks in A Coruña municipality. The methodology of the present work could be used to develop a similar wastewater-based epidemiological model to track the evolution of the COVID-19 epidemic anywhere in the world where centralized water-based sanitation systems exist.

Keywords: COVID–19; Generalized Additive Models (GAM); Kernel smoothing; LOESS; SARS-CoV-2; Wastewater-based epidemiology.

MeSH terms

COVID-19*
Epidemiological Models
Humans
RNA, Viral
SARS-CoV-2*
Spain / epidemiology
Viral Load
Wastewater

Substances

RNA, Viral
Waste Water