Long-term monitoring of SARS-COV-2 RNA in wastewater in Brazil: A more responsive and economical approach

Abstract

SARS-CoV-2, the novel Coronavirus, was first detected in Wuhan, China, in December 2019, and has since spread rapidly, causing millions of deaths worldwide. As in most countries of the world, in Brazil, the consequences of the COVID-19 pandemic have been catastrophic. Several studies have reported the fecal shedding of SARS-CoV-2 RNA titers from infected symptomatic and asymptomatic individuals. Therefore, the quantification of SARS-CoV-2 in wastewater can be used to track the virus spread in a population. In this study, samples of untreated wastewater were collected for 44 weeks at five sampling sites in the ABC Region (São Paulo, Brazil), in order to evaluate the SARS-CoV-2 occurrence in the sewerage system. SARS-CoV-2 RNA titers were detected throughout the period, and the concentration ranged from 2.7 to 7.7 log 10 genome copies.L −1 , with peaks in the last weeks of monitoring. Furthermore, we observed a positive correlation between the viral load in wastewater and the epidemiological/clinical data, with the former preceding the latter by approximately two weeks. The COVID-19 prevalence for each sampling site was estimated via Monte-Carlo simulation using the wastewater viral load. The mean predicted prevalence ranged 0.05 to 0.38%, slightly higher than reported (0.016 ± 0.005%) in the ABC Region for the same period. These results highlight the viability of the wastewater surveillance for COVID-19 infection monitoring in the largest urban agglomeration in South America. This approach can be especially useful for health agencies and public decision-makers in predicting SARS-CoV-2 outbreaks, as well as in local tracing of infection clusters.

Spatial and Temporal Trends of SARS-CoV-2 RNA from Wastewater Treatment Plants over 6 Weeks in Cape Town, South Africa

“…Low SARS-CoV-2 RNA signal in wastewater corresponded to the low number of positive COVID-19 cases in the city. In Brazil, researchers monitored the SARS-CoV-2 RNA signal in wastewater for 41 weeks in the city of São Paulo and observed a positive correlation between the RNA signal in the wastewater and clinical cases [16]. Our results are consistent with these studies.…”

RT-qPCR assays for SARS-CoV-2 variants of concern in wastewater reveals compromised vaccination-induced immunity

“…Its advantage is that it can provide critical information regarding the spread of pathogens in the population in a given area, without relying on individual testing tendencies or testing capacity. Since the beginning of the pandemic, the SARS-CoV-2 virus has been monitored in wastewater around the world ( Ahmed et al, 2020 ; Bar-Or et al, 2020 ; Claro et al, 2021 ; La Rosa et al, 2020 ; Sherchan et al, 2020 ; Trottier et al, 2020 ; Westhaus et al, 2021 ; Wu et al, 2021 , 2020 ). Despite this in order to detect specific SARS-CoV-2 variants such as the Gamma and Delta variants of concern, there is a need for a direct and sensitive probe-based RT-qPCR assay with detection ability in wastewater samples.…”

Sampling strategies for wastewater surveillance: Evaluating the variability of SARS-COV-2 RNA concentration in composite and grab samples

“…Briefly, 40 mL of samples were centrifuged (8000xg/120 min/4°C) and the pellet was resuspended in 0.4 mL of 1x PBS (pH 7.2). One milliliter of acid phenol was added and centrifuged (12.000xg/10 min/4ºC) for sample cleaning [13] . The aqueous phase was transferred to a microtube containing 0.3 mL of lysis buffer.…”

“…SARS-CoV-2 RNA was also detected in stool samples from infected individuals whose clinical tests were negative [8] . Thus, several studies have also reported the presence of SARS-CoV-2 RNA titers in municipal wastewater samples [9] , [10] , [11] , [12] and the potential use of sewage monitoring as a complementary tool for public health surveillance for COVID-19 [3] , [13] , [14] , [15] , [16] , [17] , [18] .…”

“…This sampling strategy is less susceptible to the inherent seasonal and diurnal variability of wastewater characteristics, including the viral content [34] , [35] , [36] . Several studies have reported the use of composite sampling in SARS-CoV-2 surveillance [10] , [11] , [13] , [26] . However, sampling periods longer than 6 hours have been shown to be unfeasible, especially when it is necessary to collect samples from multiple locations and areas of difficult access (sewer manholes, rivers, among others) [37] .…”