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. 2022 Dec 10;851(Pt 2):158350.
doi: 10.1016/j.scitotenv.2022.158350. Epub 2022 Aug 27.

Surveillance of SARS-CoV-2 in nine neighborhood sewersheds in Detroit Tri-County area, United States: Assessing per capita SARS-CoV-2 estimations and COVID-19 incidence

Affiliations

Surveillance of SARS-CoV-2 in nine neighborhood sewersheds in Detroit Tri-County area, United States: Assessing per capita SARS-CoV-2 estimations and COVID-19 incidence

Yabing Li et al. Sci Total Environ. .

Abstract

Wastewater-based epidemiology (WBE) has been suggested as a useful tool to predict the emergence and investigate the extent of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In this study, we screened appropriate population biomarkers for wastewater SARS-CoV-2 normalization and compared the normalized SARS-CoV-2 values across locations with different demographic characteristics in southeastern Michigan. Wastewater samples were collected between December 2020 and October 2021 from nine neighborhood sewersheds in the Detroit Tri-County area. Using reverse transcriptase droplet digital polymerase chain reaction (RT-ddPCR), concentrations of N1 and N2 genes in the studied sites were quantified, with N1 values ranging from 1.92 × 102 genomic copies/L to 6.87 × 103 gc/L and N2 values ranging from 1.91 × 102 gc/L to 6.45 × 103 gc/L. The strongest correlations were observed with between cumulative COVID-19 cases per capita (referred as COVID-19 incidences thereafter), and SARS-CoV-2 concentrations normalized by total Kjeldahl nitrogen (TKN), creatinine, 5-hydroxyindoleacetic acid (5-HIAA) and xanthine when correlating the per capita SARS-CoV-2 and COVID-19 incidences. When SARS-CoV-2 concentrations in wastewater were normalized and compared with COVID-19 incidences, the differences between neighborhoods of varying demographics were reduced as compared to differences observed when comparing non-normalized SARS-CoV-2 with COVID-19 cases. This indicates when studying the disease burden in communities of different demographics, accurate per capita estimation is of great importance. The study suggests that monitoring selected water quality parameters or biomarkers, along with RNA concentrations in wastewater, will allow adequate data normalization for spatial comparisons, especially in areas where detailed sanitary sewage flows and contributing populations in the catchment areas are not available. This opens the possibility of using WBE to assess community infections in rural areas or the developing world where the contributing population of a sample could be unknown.

Keywords: COVID-19 burdens; Detroit Tri-County area; SARS-CoV-2 RNA normalization; Wastewater-based epidemiology.

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Conflict of interest statement

Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Figures

Unlabelled Image
Graphical abstract
Fig. 1
Fig. 1
Locations of nine sewershed sites selected from the Detroit Tri-County area in Michigan in the United States. Decisions were made with local health departments and sewersheds selected represent different demographic characteristics from County Macomb (EP, MT and SH), Wayne (D1, D2 and D3) and Oakland (SF, WB and OP) in the Detroit Tri-County area MI.
Fig. 2
Fig. 2
A&B: Concentrations of SARS-CoV-2 (A: N1, B: N2) detected in samples collected from sites of County Macomb (EP, MT and SH), Wayne (D1, D2 and D3) and Oakland (SF, WB and OP) in Detroit Tri-County area, MI. One-way analysis of variance (ANOVA), followed by a Tukey's post hoc test indicates SARS-CoV-2 RNA concentrations in sewershed MT and SH are significantly higher than those in the remaining sewersheds. C&D: Loads of SARS-CoV-2 (C: N1, D: N2) calculated for sites with flow data available (Macomb: MT and SH, Wayne: D1, D2 and D3, and Oakland: SF and WB). EP and OP are absent because their flow rates are unavailable. MI. One-way analysis of variance (ANOVA), followed by a Tukey's post hoc test indicates loads of SARS-CoV-2 in sewershed MT and SH are significantly higher than those in the remaining sewersheds. E: Cumulative clinical confirmed cases for the studied period corresponding to occurrence of the 18 sampling events. F: The COVID-19 cases rate expressed as cases per 1000-person in nine neighborhood sewersheds (Macomb County: EP, MT and SH; City of Detroit (Wayne County): D1, D2 and D3; and Oakland County: SF, WB and OP) in the Detroit Tri-County area (F).
Fig. 3
Fig. 3
A: Spearman correlation analysis between SARS-CoV-2 gene N1 load and cumulative cases. B: Spearman correlation analysis between SARS-CoV-2 gene N1 load and population served by each sewershed. C: Spearman correlation analysis between SARS-CoV-2 gene N2 load and cumulative cases. D: Spearman correlation analysis between SARS-CoV-2 gene N2 load and population served by each sewershed. Correlations were performed for sewersheds with flow data available (Macomb: MT and SH, Wayne: D1, D2 and D3, and Oakland: SF and WB).
Fig. 4
Fig. 4
Correlation analysis between loads of potential population markers (including water quality parameters and human biomarkers) and population sizes obtained from census. Numbers in the shapes are the correlation coefficients. Unit of all the population markers is kept consistent and is g/day.
Fig. 5
Fig. 5
Normalize SARS-CoV-2 (A: N1; B: N2) by population markers to assess the COVID burdens to the per capita level. Correlation analyses were performed between normalized SARS-CoV-2 and COVID-19 cases per 1000-person. Events (8 events for each sewershed, from 1/18/21 to 3/22/21, dates in red in Table S1) with water quality markers, creatinine, 5-HIAA, and caffeine and its metabolites available were included to do the correlation. For each sewershed and normalizing factor, sum of the normalized SARS-CoV-2 for the 8 events were considered to do the correlation. COVID-19 cases rates were calculated for the periods corresponding to those 8 events. Unit of all the normalized SARS-CoV-2 concentrations is kept consistent and is gc/g population marker.
Fig. 6
Fig. 6
Principal component analysis (PCA) confirmed the demographic differences of the nine sampling locations in the Detroit Tri-County area, MI. A: PCA includes population sizes, total household income, proportion of different races, percent of poverty population, unemployed population and population with bachelor's degree or higher. B: PCA conducted with population markers (water quality parameters including BOD, TKN, TSS and VSS, human biomarkers including creatinine, 5-HIAA, caffeine and its metabolites). C: PCA conducted with parameters from wastewater surveillance (SARS-CoV-2 RNA concentrations targeting at N1 and N2, water quality parameters including BOD, TKN, TSS and VSS, human biomarkers including creatinine, 5-HIAA, caffeine and its metabolites). D: PCA conducted with SARS-CoV-2 RNA concentrations (targeting at both N1 and N2 genes) normalized by TKN, creatinine, 5-HIAA and xanthine.

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References

    1. Ahmed W., Bibby K., D'Aoust P.M., Delatolla R., Gerba C.P., Haas C.N., Hamilton K.A., Hewitt J., Julian T.R., Kaya D., Monis P., Moulin L., Naughton C., Noble R.T., Shrestha A., Tiwari A., Simpson S.L., Wurtzer S., Bivins A. Differentiating between the possibility and probability of SARS-CoV-2 transmission associated with wastewater: empirical evidence is needed to substantiate risk. FEMS Microbes. 2021;2 doi: 10.1093/femsmc/xtab007. - DOI
    1. Ahmed W., Bivins A., Metcalfe S., Smith W.J.M., Ziels R., Korajkic A., McMinn B., Graber T.E., Simpson S.L. RT-qPCR and ATOPlex sequencing for the sensitive detection of SARS-CoV-2 RNA for wastewater surveillance. Water Res. 2022;220 doi: 10.1016/j.watres.2022.118621. - DOI - PMC - PubMed
    1. Ahmed W., Bivins A., Simpson S.L., Bertsch P.M., Ehret J., Hosegood I., Metcalfe S.S., Smith W.J.M., Thomas K.V., Tynan J., Mueller J.F. Wastewater surveillance demonstrates high predictive value for COVID-19 infection on board repatriation flights to Australia. Environ. Int. 2022;158 doi: 10.1016/j.envint.2021.106938. - DOI - PMC - PubMed
    1. Ahmed W., Bivins A., Smith W.J.M., Metcalfe S., Stephens M., Jennison A.V., Moore F.A.J., Bourke J., Schlebusch S., McMahon J., Hewitson G., Nguyen S., Barcelon J., Jackson G., Mueller J.F., Ehret J., Hosegood I., Tian W., Wang H., Yang L., Bertsch P.M., Tynan J., Thomas K.V., Bibby K., Graber T.E., Ziels R., Simpson S.L. Detection of the omicron (B.1.1.529) variant of SARS-CoV-2 in aircraft wastewater. Sci. Total Environ. 2022;820 doi: 10.1016/j.scitotenv.2022.153171. - DOI - PMC - PubMed
    1. Ahmed W., Tscharke B., Bertsch P.M., Bibby K., Bivins A., Choi P., Clarke L., Dwyer J., Edson J., Nguyen T.M.H., O'Brien J.W., Simpson S.L., Sherman P., Thomas K.V., Verhagen R., Zaugg J., Mueller J.F. SARS-CoV-2 RNA monitoring in wastewater as a potential early warning system for COVID-19 transmission in the community: a temporal case study. Sci. Total Environ. 2021;761 doi: 10.1016/j.scitotenv.2020.144216. - DOI - PMC - PubMed