Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2023 Jul 21;26(7):107019.
doi: 10.1016/j.isci.2023.107019. Epub 2023 Jun 9.

COVID-19 monitoring with sparse sampling of sewered and non-sewered wastewater in urban and rural communities

Affiliations

COVID-19 monitoring with sparse sampling of sewered and non-sewered wastewater in urban and rural communities

Dhammika Leshan Wannigama et al. iScience. .

Abstract

Equitable SARS-CoV-2 surveillance in low-resource communities lacking centralized sewers is critical as wastewater-based epidemiology (WBE) progresses. However, large-scale studies on SARS-CoV-2 detection in wastewater from low-and middle-income countries is limited because of economic and technical reasons. In this study, wastewater samples were collected twice a month from 186 urban and rural subdistricts in nine provinces of Thailand mostly having decentralized and non-sewered sanitation infrastructure and analyzed for SARS-CoV-2 RNA variants using allele-specific RT-qPCR. Wastewater SARS-CoV-2 RNA concentration was used to estimate the real-time incidence and time-varying effective reproduction number (Re). Results showed an increase in SARS-CoV-2 RNA concentrations in wastewater from urban and rural areas 14-20 days earlier than infected individuals were officially reported. It also showed that community/food markets were "hot spots" for infected people. This approach offers an opportunity for early detection of transmission surges, allowing preparedness and potentially mitigating significant outbreaks at both spatial and temporal scales.

Keywords: Applied microbiology; Environmental monitoring; Molecular microbiology; Virology.

PubMed Disclaimer

Conflict of interest statement

No author declares any potential conflict of interest or competing financial or non-financial interest in relation to the manuscript.

Figures

None
Graphical abstract
Figure 1
Figure 1
Estimation of infection incidence and effective reproductive number for SARS-CoV-2 (A–D) (A) confirmed positive cases, (B) RNA concentration in wastewater, (C) comparison of daily SARS-CoV-2 confirmed cases, infection incidence estimated based on confirmed cases, and infection incidence estimated based on SARS-CoV-2 RNA concentration in wastewater for Bangkok, and (D) comparison of the effective reproductive numbers estimated using the case-based infection incidence (red line) and wastewater-based infection incidence (green line). The ribbons display the standard deviation of 1,000 bootstrap replicates.
Figure 2
Figure 2
Map for SARS-CoV-2 RNA in wastewater and reported cases (A–C) (A) confirmed positive SARS-CoV-2 cases, (B) SARS-CoV-2 RNA concentration in wastewater, and (C) percent of variant per total SARS-CoV-2 RNA concentration in wastewater.
Figure 3
Figure 3
Relative abundance of different SARS-CoV-2 viral variants in Wastewater SARS-CoV-2RNA concentration for each variant in wastewater and infection incidence estimated from each variant’s viral loads in wastewater for (A and B) Bangkok, (C and D) Nakhon Pathom, and (E and F) Rural areas. The ribbons show the standard deviation across 1,000 bootstrap replicates. (G) Relative abundance shows the transition of variants of viral loads in wastewater for each area.
Figure 4
Figure 4
SARS-CoV-2 RNA concentration in wastewater collected from different facilities (A–F) (A) Bangkok and (D) Rural areas. Relative abundance in SARS-CoV-2 RNA concentration in wastewater collected from different facilities in (C) Bangkok and (F) Rural areas. Infection incidences based on SARS-CoV-2 RNA concentration in (B) Bangkok and (E) Rural areas. The ribbons show the standard deviation of 1,000 bootstrap replicates. Gray areas show the period during a nationwide ban on large events to ease lockdown (26-Dec-20 to 29-Jan-21, and 17-Apr-21 to 01-Sep-21). The black labels show the superspreading events, and the red labels are the starting of interventions.
Figure 5
Figure 5
Relationship between SARS-CoV-2 RNA concentration in wastewater and reported cases (A) GCV values of the fitting models, the number of cases obtained from the best model (red line) compared to the reported cases (black dots) with their confidence intervals (ribbons) in (B) Total, (C) Bangkok, (D) Nakhon Pathom, (E) Nonthaburi, (F) Pathum Thani, (G) Samut Prakan, and (H) Samut Sakhon.

Similar articles

Cited by

References

    1. Pinilla J., Barber P., Vallejo-Torres L., Rodríguez-Mireles S., López-Valcárcel B.G., Serra-Majem L. The economic impact of the SARS-COV-2 (COVID-19) pandemic in Spain. Int. J. Environ. Res. Public Health. 2021;18:4708. doi: 10.3390/ijerph18094708. - DOI - PMC - PubMed
    1. Liu F., Zhao Z., Ma C., Nie X., Wu A., Li X. Return to normal pre-COVID-19 life is delayed by inequitable vaccine allocation and SARS-CoV-2 variants. Epidemiol. Infect. 2022;150:e46. doi: 10.1017/s0950268822000139. - DOI - PMC - PubMed
    1. Andrews N., Stowe J., Kirsebom F., Toffa S., Sachdeva R., Gower C., Ramsay M., Lopez Bernal J. Effectiveness of COVID-19 booster vaccines against COVID-19-related symptoms, hospitalization and death in England. Nat. Med. 2022;28:831–837. doi: 10.1038/s41591-022-01699-1. - DOI - PMC - PubMed
    1. Mills E.J., Reis G. Evaluating COVID-19 vaccines in the real world. Lancet. 2022;399:1205–1206. doi: 10.1016/S0140-6736(22)00194-5. - DOI - PMC - PubMed
    1. University J.H. Johns Hopkins University Coronavirus Resource Center; 2023. COVID 19 Dashboard.

LinkOut - more resources