Unravelling the early warning capability of wastewater surveillance for COVID-19: A temporal study on SARS-CoV-2 RNA detection and need for the escalation

Abstract

Wastewater-based Epidemiological (WBE) surveillance offers a promising approach to assess the pandemic situation covering pre-symptomatic and asymptomatic cases in highly populated area under limited clinical tests. In the present study, we analysed SARS-CoV-2 RNA in the influent wastewater samples ( n = 43) from four wastewater treatment plants (WWTPs) in Gandhinagar, India, during August 7 th to September 30 th , 2020. A total of 40 samples out of 43 were found positive i.e. having at least two genes of SARS-CoV-2. The average Ct values for S, N, and ORF 1ab genes were 32.66, 33.03, and 33.95, respectively. Monthly variation depicted a substantial rise in the average copies of N (∼120%) and ORF 1ab (∼38%) genes in the month of September as compared to August, while S-gene copies declined by 58% in September 2020. The SARS-CoV-2 genome concentration was higher in the month of September (∼924.5 copies/L) than August (∼897.5 copies/L), corresponding to a ∼ 2.2-fold rise in the number of confirmed cases during the study period. Further, the percentage change in genome concentration level on a particular date was found in the lead of 1-2 weeks of time with respect to the official confirmed cases registered based on clinical tests on a temporal scale. The results profoundly unravel the potential of WBE surveillance to predict the fluctuation of COVID-19 cases to provide an early warning. Our study explicitly suggests that it is the need of hour that the wastewater surveillance must be included as an integral part of COVID-19 pandemic monitoring which can not only help the water authorities to identify the hotspots within a city but can provide up to 2 weeks of time lead for better tuning the management interventions.

First comparison of conventional activated sludge versus root-zone treatment for SARS-CoV-2 RNA removal from wastewaters: Statistical and temporal significance

“…The results obtained from ANOVA analysis were reported as (F critical = F calculated , significant level P) and if F calculated value is greater than F critical value, the null hypothesis will be rejected. The Statistical Package for the Social Sciences (SPSS 21) was used for hypothesis testing and multivariate analyses (MVA) to determine the significance of removal efficacy and relatedness of various water quality parameters with SARS-CoV-2 genes through paired t-tests and principal component analysis (PCA), respectively, after Z-score data normalization [41] . A non-related principal components (PCs) was generated using orthogonal varimax rotation, and the results were projected on three-dimensional loading domain.…”

“…In general, wastewater surveillance of SARS-CoV-2 has focused on early-warning capability verifications [8] , [11] , [16] , [41] , [42] ), or protocol improvement through comparing various techniques of concentration and precipitations [13] , [42] , [43] , and solid-aqueous interactions from sludge and virus interaction perspectives [29] , [44] , [45] . However, since the beginning, subtle parallel efforts were there to check the SARS-CoV-2 RNA presence in secondary- and tertiary-treated wastewater.…”

“…Therefore, it is novel to perform a comparative study, including both untreated and treated wastewater samples to assess the efficacy of treatment plants. While multivariate analysis (MVA) helps source apportionment for environmental samples, it projects unbiased relationships among parameters and their contribution to variations in the data set [41] . To date, however, reported wastewater surveillance datasets have not been large enough for MVA.…”

Reflections of COVID-19 cases in the wastewater loading of SARS-CoV-2 RNA: A case of three major cities of Gujarat, India

“…The release of the SARS-CoV-2 virus to the gastrointestinal tract endorses the possible fecal-oral transmission route [ 17 ]. Likewise, the presence of SARS-CoV-2 RNA in the sewerage, untreated/treated wastewater, and contaminated natural water bodies raise the alarm for possible transmission routes via these aqueous matrices [ 6 , [18] , [19] , [20] , [21] , [22] , [23] , [24] , [25] ]. Amidst various debatable questions related to the origin, transmission, stability, and decay of SARS-CoV-2, it is pertinent to develop a pre-alarming tool for effective COVID-19 preparedness and knowing the actual prevalence of disease at the community level.…”

Early detections of SARS-CoV-2 in wastewater and their use in COVID-19 epidemiological control

“…D'Aoust et al (2021), investigating primary clarified sludge samples obtained in the treatment plant of the city of Ottawa, identified an increase in the SARS-CoV-2 viral signals in wastewater 48 hours before positive COVID-19 clinical tests and 96 hours before local hospitalizations Kumar et al (2021). also observed a change on the SARS-CoV-2 genome particles concentration in wastewater samples collected one to two weeks before official clinical cases in the studied location of Gandhinagar, Gujarat, India Randazzo et al (2020),.…”