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Prasek SM, Pepper IL, Innes GK, Slinski S, Ruedas M, Sanchez A, Brierley P, Betancourt WQ, Stark ER, Foster AR, Betts-Childress ND, Schmitz BW. Population level SARS-CoV-2 fecal shedding rates determined via wastewater-based epidemiology. Sci Total Environ 2022; 838:156535. [PMID: 35688254 PMCID: PMC9172256 DOI: 10.1016/j.scitotenv.2022.156535] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Revised: 05/14/2022] [Accepted: 06/03/2022] [Indexed: 05/21/2023]
Abstract
Wastewater-based epidemiology (WBE) has been utilized as an early warning tool to anticipate disease outbreaks, especially during the COVID-19 pandemic. However, COVID-19 disease models built from wastewater-collected data have been limited by the complexities involved in estimating SARS-CoV-2 fecal shedding rates. In this study, wastewater from six municipalities in Arizona and Florida with distinct demographics were monitored for SARS-CoV-2 RNA between September 2020 and December 2021. Virus concentrations with corresponding clinical case counts were utilized to estimate community-wide fecal shedding rates that encompassed all infected individuals. Analyses suggest that average SARS-CoV-2 RNA fecal shedding rates typically occurred within a consistent range (7.53-9.29 log10 gc/g-feces); and yet, were unique to each community and influenced by population demographics. Age, ethnicity, and socio-economic factors may have influenced shedding rates. Interestingly, populations with median age between 30 and 39 had the greatest fecal shedding rates. Additionally, rates remained relatively constant throughout the pandemic provided conditions related to vaccination and variants were unchanged. Rates significantly increased in some communities when the Delta variant became predominant. Findings in this study suggest that community-specific shedding rates may be appropriate in model development relating wastewater virus concentrations to clinical case counts.
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Affiliation(s)
- Sarah M Prasek
- Water & Energy Sustainable Technology (WEST) Center, University of Arizona, 2959 W. Calle Agua Nueva, Tucson, AZ 85745, USA
| | - Ian L Pepper
- Water & Energy Sustainable Technology (WEST) Center, University of Arizona, 2959 W. Calle Agua Nueva, Tucson, AZ 85745, USA
| | - Gabriel K Innes
- Yuma Center of Excellence for Desert Agriculture (YCEDA), University of Arizona, 6425 W. 8(th) St., Yuma, AZ 85364, USA
| | - Stephanie Slinski
- Yuma Center of Excellence for Desert Agriculture (YCEDA), University of Arizona, 6425 W. 8(th) St., Yuma, AZ 85364, USA
| | - Martha Ruedas
- Yuma Center of Excellence for Desert Agriculture (YCEDA), University of Arizona, 6425 W. 8(th) St., Yuma, AZ 85364, USA
| | - Ana Sanchez
- Yuma Center of Excellence for Desert Agriculture (YCEDA), University of Arizona, 6425 W. 8(th) St., Yuma, AZ 85364, USA
| | - Paul Brierley
- Yuma Center of Excellence for Desert Agriculture (YCEDA), University of Arizona, 6425 W. 8(th) St., Yuma, AZ 85364, USA
| | - Walter Q Betancourt
- Water & Energy Sustainable Technology (WEST) Center, University of Arizona, 2959 W. Calle Agua Nueva, Tucson, AZ 85745, USA
| | - Erika R Stark
- Water & Energy Sustainable Technology (WEST) Center, University of Arizona, 2959 W. Calle Agua Nueva, Tucson, AZ 85745, USA
| | - Aidan R Foster
- Water & Energy Sustainable Technology (WEST) Center, University of Arizona, 2959 W. Calle Agua Nueva, Tucson, AZ 85745, USA
| | - Nick D Betts-Childress
- Water & Energy Sustainable Technology (WEST) Center, University of Arizona, 2959 W. Calle Agua Nueva, Tucson, AZ 85745, USA
| | - Bradley W Schmitz
- Yuma Center of Excellence for Desert Agriculture (YCEDA), University of Arizona, 6425 W. 8(th) St., Yuma, AZ 85364, USA.
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Schmitz BW, Innes GK, Prasek SM, Betancourt WQ, Stark ER, Foster AR, Abraham AG, Gerba CP, Pepper IL. Enumerating asymptomatic COVID-19 cases and estimating SARS-CoV-2 fecal shedding rates via wastewater-based epidemiology. Sci Total Environ 2021; 801:149794. [PMID: 34467933 PMCID: PMC8378060 DOI: 10.1016/j.scitotenv.2021.149794] [Citation(s) in RCA: 60] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 08/15/2021] [Accepted: 08/16/2021] [Indexed: 04/15/2023]
Abstract
Wastewater-based epidemiology (WBE) was utilized to monitor SARS-CoV-2 RNA in sewage collected from manholes specific to individual student dormitories (dorms) at the University of Arizona in the fall semester of 2020, which led to successful identification and reduction of SARS-CoV-2 transmission events. Positive wastewater samples triggered clinical testing of residents within that dorm; thus, SARS-CoV-2 infected individuals were identified regardless of symptom expression. This current study examined clinical testing data to determine the abundance of asymptomatic versus symptomatic cases in these defined communities. Nasal and nasopharyngeal swab samples processed via antigen and PCR tests indicated that 79.2% of SARS-CoV-2 infections were asymptomatic, and only 20.8% of positive cases reported COVID-19 symptoms at the time of testing. Clinical data was paired with corresponding wastewater virus concentrations, which enabled calculation of viral shedding rates in feces per infected person. Mean shedding rates averaged from positive wastewater samples across all dorms were 7.30 ± 0.67 log10 genome copies per gram of feces (gc/g-feces) based on the N1 gene. Quantification of SARS-CoV-2 fecal shedding rates from infected individuals has been the critical missing component necessary for WBE models to measure and predict SARS-CoV-2 infection prevalence in communities. The findings from this study can be utilized to create models that can be used to inform public health prevention and response actions.
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Affiliation(s)
- Bradley W Schmitz
- Yuma Center of Excellence for Desert Agriculture (YCEDA), University of Arizona, 6425 W. 8th St., Yuma, AZ 85364, USA.
| | - Gabriel K Innes
- Department of Epidemiology, School of Public Health, Rutgers University, 683 Hoes Lane West, Piscataway, NJ 08854, USA
| | - Sarah M Prasek
- Water & Energy Sustainable Technology (WEST) Center, University of Arizona, 2959 W. Calle Agua Nueva, Tucson, AZ 85745, USA
| | - Walter Q Betancourt
- Water & Energy Sustainable Technology (WEST) Center, University of Arizona, 2959 W. Calle Agua Nueva, Tucson, AZ 85745, USA
| | - Erika R Stark
- Water & Energy Sustainable Technology (WEST) Center, University of Arizona, 2959 W. Calle Agua Nueva, Tucson, AZ 85745, USA
| | - Aidan R Foster
- Water & Energy Sustainable Technology (WEST) Center, University of Arizona, 2959 W. Calle Agua Nueva, Tucson, AZ 85745, USA
| | - Alison G Abraham
- Department of Epidemiology, School of Public Health, University of Colorado Anschutz Medical Campus, 1635 Aurora Ct, Aurora, CO 80045, USA
| | - Charles P Gerba
- Water & Energy Sustainable Technology (WEST) Center, University of Arizona, 2959 W. Calle Agua Nueva, Tucson, AZ 85745, USA
| | - Ian L Pepper
- Water & Energy Sustainable Technology (WEST) Center, University of Arizona, 2959 W. Calle Agua Nueva, Tucson, AZ 85745, USA
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Schmitz BW, Innes GK, Prasek SM, Betancourt WQ, Stark ER, Foster AR, Abraham AG, Gerba CP, Pepper IL. Enumerating asymptomatic COVID-19 cases and estimating SARS-CoV-2 fecal shedding rates via wastewater-based epidemiology. Sci Total Environ 2021; 801:149794. [PMID: 34467933 DOI: 10.1101/2021.04.16.21255638] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 08/15/2021] [Accepted: 08/16/2021] [Indexed: 05/18/2023]
Abstract
Wastewater-based epidemiology (WBE) was utilized to monitor SARS-CoV-2 RNA in sewage collected from manholes specific to individual student dormitories (dorms) at the University of Arizona in the fall semester of 2020, which led to successful identification and reduction of SARS-CoV-2 transmission events. Positive wastewater samples triggered clinical testing of residents within that dorm; thus, SARS-CoV-2 infected individuals were identified regardless of symptom expression. This current study examined clinical testing data to determine the abundance of asymptomatic versus symptomatic cases in these defined communities. Nasal and nasopharyngeal swab samples processed via antigen and PCR tests indicated that 79.2% of SARS-CoV-2 infections were asymptomatic, and only 20.8% of positive cases reported COVID-19 symptoms at the time of testing. Clinical data was paired with corresponding wastewater virus concentrations, which enabled calculation of viral shedding rates in feces per infected person. Mean shedding rates averaged from positive wastewater samples across all dorms were 7.30 ± 0.67 log10 genome copies per gram of feces (gc/g-feces) based on the N1 gene. Quantification of SARS-CoV-2 fecal shedding rates from infected individuals has been the critical missing component necessary for WBE models to measure and predict SARS-CoV-2 infection prevalence in communities. The findings from this study can be utilized to create models that can be used to inform public health prevention and response actions.
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Affiliation(s)
- Bradley W Schmitz
- Yuma Center of Excellence for Desert Agriculture (YCEDA), University of Arizona, 6425 W. 8th St., Yuma, AZ 85364, USA.
| | - Gabriel K Innes
- Department of Epidemiology, School of Public Health, Rutgers University, 683 Hoes Lane West, Piscataway, NJ 08854, USA
| | - Sarah M Prasek
- Water & Energy Sustainable Technology (WEST) Center, University of Arizona, 2959 W. Calle Agua Nueva, Tucson, AZ 85745, USA
| | - Walter Q Betancourt
- Water & Energy Sustainable Technology (WEST) Center, University of Arizona, 2959 W. Calle Agua Nueva, Tucson, AZ 85745, USA
| | - Erika R Stark
- Water & Energy Sustainable Technology (WEST) Center, University of Arizona, 2959 W. Calle Agua Nueva, Tucson, AZ 85745, USA
| | - Aidan R Foster
- Water & Energy Sustainable Technology (WEST) Center, University of Arizona, 2959 W. Calle Agua Nueva, Tucson, AZ 85745, USA
| | - Alison G Abraham
- Department of Epidemiology, School of Public Health, University of Colorado Anschutz Medical Campus, 1635 Aurora Ct, Aurora, CO 80045, USA
| | - Charles P Gerba
- Water & Energy Sustainable Technology (WEST) Center, University of Arizona, 2959 W. Calle Agua Nueva, Tucson, AZ 85745, USA
| | - Ian L Pepper
- Water & Energy Sustainable Technology (WEST) Center, University of Arizona, 2959 W. Calle Agua Nueva, Tucson, AZ 85745, USA
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Betancourt WQ, Schmitz BW, Innes GK, Prasek SM, Pogreba Brown KM, Stark ER, Foster AR, Sprissler RS, Harris DT, Sherchan SP, Gerba CP, Pepper IL. COVID-19 containment on a college campus via wastewater-based epidemiology, targeted clinical testing and an intervention. Sci Total Environ 2021; 779:146408. [PMID: 33743467 PMCID: PMC7954642 DOI: 10.1016/j.scitotenv.2021.146408] [Citation(s) in RCA: 173] [Impact Index Per Article: 57.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 03/05/2021] [Accepted: 03/06/2021] [Indexed: 05/04/2023]
Abstract
Wastewater-based epidemiology has potential as an early-warning tool for determining the presence of COVID-19 in a community. The University of Arizona (UArizona) utilized WBE paired with clinical testing as a surveillance tool to monitor the UArizona community for SARS-CoV-2 in near real-time, as students re-entered campus in the fall. Positive detection of virus RNA in wastewater lead to selected clinical testing, identification, and isolation of three infected individuals (one symptomatic and two asymptomatic) that averted potential disease transmission. This case study demonstrated the value of WBE as a tool to efficiently utilize resources for COVID-19 prevention and response. Thus, WBE coupled with targeted clinical testing was further conducted on 13 dorms during the course of the Fall semester (Table 3). In total, 91 wastewater samples resulted in positive detection of SARS-CoV-2 RNA that successfully provided an early-warning for at least a single new reported case of infection (positive clinical test) among the residents living in the dorm. Overall, WBE proved to be an accurate diagnostic for new cases of COVID-19 with an 82.0% positive predictive value and an 88.9% negative predictive value. Increases in positive wastewater samples and clinical tests were noted following holiday-related activities. However, shelter-in-place policies proved to be effective in reducing the number of daily reported positive wastewater and clinical tests. This case study provides evidence for WBE paired with clinical testing and public health interventions to effectively contain potential outbreaks of COVID-19 in defined communities.
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Affiliation(s)
- Walter Q Betancourt
- Water & Energy Sustainable Technology (WEST) Center, University of Arizona, 2959 W. Calle Agua Nueva, Tucson, AZ 85745, USA
| | - Bradley W Schmitz
- Yuma Center of Excellence for Desert Agriculture (YCEDA), University of Arizona, 6425 W. 8th St., Yuma, AZ 85364, USA
| | - Gabriel K Innes
- Department of Epidemiology, School of Public Health, Rutgers University, 683 Hoes Lane West, Piscataway, NJ 08854, USA
| | - Sarah M Prasek
- Water & Energy Sustainable Technology (WEST) Center, University of Arizona, 2959 W. Calle Agua Nueva, Tucson, AZ 85745, USA
| | - Kristen M Pogreba Brown
- Mel & Enid Zukerman College of Public Health, University of Arizona, 1295 N. Martin Ave., Tucson, AZ 85724, USA
| | - Erika R Stark
- Water & Energy Sustainable Technology (WEST) Center, University of Arizona, 2959 W. Calle Agua Nueva, Tucson, AZ 85745, USA
| | - Aidan R Foster
- Water & Energy Sustainable Technology (WEST) Center, University of Arizona, 2959 W. Calle Agua Nueva, Tucson, AZ 85745, USA
| | - Ryan S Sprissler
- Center for Applied Genetics and Genomic Medicine, University of Arizona, 1295 N. Martin Ave., Tucson, AZ 85721, USA
| | - David T Harris
- Department of Immunobiology, College of Medicine, University of Arizona, 1656 E. Mabel St., Tucson, AZ 85724, USA
| | - Samendra P Sherchan
- Department of Environmental Health Sciences, School of Public Health and Tropical Medicine, Tulane University, 1440 Canal St., New Orleans, LA 70112, USA
| | - Charles P Gerba
- Water & Energy Sustainable Technology (WEST) Center, University of Arizona, 2959 W. Calle Agua Nueva, Tucson, AZ 85745, USA
| | - Ian L Pepper
- Water & Energy Sustainable Technology (WEST) Center, University of Arizona, 2959 W. Calle Agua Nueva, Tucson, AZ 85745, USA.
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