Predicting COVID-19 Infected Individuals in a Defined Population from Wastewater RNA Data

Abstract

Wastewater surveillance of SARS-CoV-2 RNA has become an important tool for tracking the presence of the virus and serving as an early indicator for the onset of rapid transmission. Nevertheless, wastewater data are still not commonly used to predict the number of infected individuals in a sewershed. The main objective of this study was to calibrate a susceptible-exposed-infectious-recovered (SEIR) model using RNA copy rates in sewage (i.e., gene copies per liter times flow rate) and the number of SARS-CoV-2 saliva-test-positive infected individuals in a university student population that was subject to repeated weekly testing during the Spring 2021 semester. A strong correlation was observed between the RNA copy rates and the number of infected individuals. The parameter in the SEIR model that had the largest impact on calibration was the maximum shedding rate, resulting in a mean value of 7.72 log 10 genome copies per gram of feces. Regressing the saliva-test-positive infected individuals on predictions from the SEIR model based on the RNA copy rates yielded a slope of 0.87 (SE = 0.11), which is statistically consistent with a 1:1 relationship between the two. These findings demonstrate that wastewater surveillance of SARS-CoV-2 can be used to estimate the number of infected individuals in a sewershed.

Wastewater-based surveillance of COVID-19 and removal of SARS-CoV-2 RNA across a major wastewater treatment plant in San Antonio, Texas

“…Furthermore, these results suggest that recurring COVID-19 outbreaks in the sewershed contribute to the SARS-CoV-2 viral RNA loading into local WWTPs. 45,46 Wastewater samples collected during the third wave of COVID-19 cases (July–August 2021) showed relatively higher SARS-CoV-2 RNA concentrations as compared to other periods in the study area. 35,38 Notably, the SARS-COV-2 RNA levels were relatively lower from April–June 2021 and September–November 2021, which corresponded well with the initiation of vaccination in the study area and the decline in daily incident COVID-19 cases after the third wave, respectively.…”

Biolayer-Interferometry-Guided Functionalization of Screen-Printed Graphene for Label-Free Electrochemical Virus Detection

“…Samples were stripped of personal identifiers, and one aliquot was used to quantify the viral load of SARS-CoV-2 at the Clemson University Research and Education in Disease Diagnosis and Intervention (REDDI) Lab (CLIA# 42D2193465). The TigerSaliva multiplex RT-qPCR saliva diagnosis test was used to quantify the concentration of the SARS-CoV-2 virus in the clinical samples using previously established methods. − Briefly, the saliva samples were heat-treated at 95 °C for 30 min, and 2 μL was transferred automatically to a 384-well plate by an open-source sample handler (Opentrons OT-2). The plates were loaded into a thermocycler (Bio-Rad CFX 384) for amplification.…”

An epidemiological modeling framework to inform institutional-level response to infectious disease outbreaks: a Covid-19 case study

“…Student isolation and quarantine was tracked using a management system, including the software Atlassian Jira 56 . A description for the data application and collection processes are illustrated in McMahan et al (Figure S1) 57 . Ethical review for this study and obtained by Institutional Review Board of Clemson University (IRB # 2021-043-02).…”