Examining the Correlation and Lead Time Between Reported COVID-19 Cases and SARS-CoV-2 RNA Concentrations in Wastewater Influent Catchment Areas in Fulton County, Georgia Open Access

Cavallo, Matthew (Spring 2022)

Permanent URL: https://etd.library.emory.edu/concern/etds/7d278v26x?locale=en


INTRODUCTION: Wastewater-based surveillance quickly gained popularity during the COVID-19 pandemic as an effective and non-invasive surveillance system for understanding COVID-19 burden within a wastewater facility catchment area. The ability to detect SARS-CoV-2 RNA from cases that are not reported, or asymptomatic cases, provides a unique advantage over traditional diagnostic testing. OBJECTIVE: The objective of this analysis was to examine how SARS-CoV-2 RNA concentrations in wastewater correlate with reported COVID-19 cases. The time with which rising SARS-CoV-2 RNA concentrations precede increasing reported COVID-19 cases was also examined. METHODS: Wastewater samples were collected from six influent lines servicing known catchment areas from February 2021-April 2022. Samples (n=257) were processed for viral concentration and RNA extraction, followed by quantitative RT-PCR. Reported COVID-19 case data (n=40,294) were collected from the Georgia Department of Public Health, then geocoded by patient address, to determine weekly number of reported COVID-19 cases for each influent catchment area basin. Linear regression and correlation analysis were conducted to examine the relationship between these variables. RESULTS: SARS-CoV-2 RNA in wastewater and reported COVID-19 cases showed a positive correlation for each of the six influent line catchment areas.  The line of best fit for each linear regression was weak, potentially due to a variety of biological and environmental factors. The correlation analysis indicated that SARS-CoV-2 RNA concentrations preceded reported COVID-19 cases by one week for five influent line catchment areas (r ranged from 0.415-0.804), and two weeks for one influent line catchment area (r=0.829). DISCUSSION: The relationship between SARS-CoV-2 RNA concentration in wastewater and reported COVID-19 cases in the catchment areas is complex. Future research will need to take into account the effect of environmental factors, such as wastewater facility flow rate and precipitation levels; biological factors, such as variable viral shedding; and socio-behavioral factors, such as diagnostic testing access. A one-week lead time is an important advantage of wastewater-based surveillance that allows health officials to mobilize resources and prepare for potential case spikes. As COVID-19 incidence decreases and diagnostic testing declines, wastewater-based surveillance will continue to be an important tool for understanding community COVID-19 burden and mitigating potential outbreaks.

Table of Contents

Table of Contents

Literature Review

Introduction                                                                                                                            1

Wastewater Surveillance for Viral Pathogens                                                                        3

Wastewater Surveillance Applications                                                                                   5

Fulton County Demographics                                                                                                 9

Research Question                                                                                                                  11


Wastewater Sampling                                                                                                             12

Virus Concentration and RNA Extraction                                                                              13

Data Analysis                                                                                                                          14


Reported COVID-19 case and SARS-CoV-2 genome copies trends                                     15

Estimating COVID-19 population prevalence from measured SARS-CoV-2 RNA concentration in wastewater                                                                                                                                    16

Lead Time Estimation                                                                                                            18


Applications                                                                                                                            19

Existing Literature                                                                                                                  21

Limitations                                                                                                                              24

Recommendations                                                                                                                  25

Conclusion                                                                                                                              29

Appendix                                                                                                                              30

References                                                                                                                             38


About this Master's Thesis

Rights statement
  • Permission granted by the author to include this thesis or dissertation in this repository. All rights reserved by the author. Please contact the author for information regarding the reproduction and use of this thesis or dissertation.
Subfield / Discipline
  • English
Research Field
Committee Chair / Thesis Advisor
Last modified

Primary PDF

Supplemental Files