SARS-CoV-2 in Human Sewage and River Water from a Remote and Vulnerable Area as a Surveillance Tool in Brazil

Abstract

In the present study, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was monitored in environmental samples from rural and vulnerable areas (a presidio, worker accommodation units, and river waters upstream and downstream of a rural community) from Minas Gerais State region, Southern Brazil, in August 2020. The sampling was performed prior to official declaration of the coronavirus disease (COVID-19) cases in those sites. SARS-CoV-2 RNA was detected in the presidio and workers accommodation units (3.0 × 10 4 virus genome copies (GC)/mL and 4.3 × 10 4 GC/mL of sewage, respectively). While SARS-CoV-2 was not detected in the river water upstream of the rural community, SARS-CoV-2 RNA was detected in downstream river waters (1.1 × 10 2 SARS-CoV-2 GC/mL). The results obtained in this study highlight the utility of SARS-CoV-2 monitoring in wastewater and human sewage as a non-invasive early warning tool to support health surveillance in vulnerable and remote areas, particularly in development countries.

One-Year Surveillance of SARS-CoV-2 Virus in Natural and Drinking Water

“…SARS-CoV-2 RNA was detected and quantified in two of the 43 natural water samples, with concentrations of 23,757 gc/L and 8035 gc/L—higher than those found by Mahlknecht et al [ 13 ] in surface water (3.3–3.8 gc/mL) and in river waters (2.5–7.0 gc/mL) from Mexico, and lower than the concentrations found in the study by Fongaro et al [ 14 ] in river water downstream of a rural community of Brazil (1.1 × 10 2 gc/mL), or in the work of Tandukar et al [ 15 ] in the water of a river from Nepal (4.0 to 5.0 log10 gc/L).…”

“…SARS-CoV-2 RNA was detected in two natural surface water sources (Dam reservoir_C and Dam reservoir_P), as had already happened in other countries—namely, Italy [ 11 ], Mexico [ 13 ], Brazil [ 14 ], and Nepal [ 15 ]. However, in the referred studies, the viral RNA was detected in water samples taken from rivers—not from dam reservoirs, as occurred in the present project.…”

“…Later, in Mexico, Mahlknecht et al [ 13 ] found SARS-CoV-2 RNA in surface water (3.3–3.8 gc/mL), groundwater (2.6–38.3 gc/mL), river water (2.5–7.0 gc/mL) and wastewater (up to 3535 gc/mL). In Brazil, in a study by Fongaro et al [ 14 ] in August 2020, viral RNA was found in the water of a river downstream of a rural community in Minas Gerais (1.1 × 10 2 gc/mL). In Nepal, Tandukar et al [ 15 ] detected SARS-CoV-2 RNA in the water of a river at a concentration of 4.0 to 5.0 log10 gc/L, in addition to also having been found in wastewater.…”

Centralized and decentralized wastewater-based epidemiology to infer COVID-19 transmission – A brief review

“…The detection and quantification of SARS-CoV-2 in polluted surface waters contaminated with sewage could represent an complementary epidemiological tool for viral surveillance [ [63] , [64] , [65] ]. Studies have been made accessing the concentrations of SARS-CoV-2 RNA in decentralized sewer networks, rivers and sewer interceptors and are summarized in Table 2 [ 47 , 53 , [66] , [67] , [68] , [69] , [70] ]. [ 47 ], suggests that decentralized sewage monitoring could identify hotspots in a city and help major cities in dealing with the current pandemic [ 47 ].…”

“… In the rural area assessed, human sewage is released directly to the river waters and basic sanitation systems are not available. [ 66 ] Belo Horizonte, Brazil May 10th to August 1st, 2020 WWTP; Sewer interceptors 204 COVID-cases hotspots need to be identified based on data generated by decentralized sewage monitoring, instead of clinal data. [ 47 ] …”