ABSTRACT
Wastewater-based epidemiology (WBE) surveillance could play a key role in managing the COVID-19 pandemic by covering pre-symptomatic and asymptomatic cases in highly populated areas with limited clinical tests. In the present work, wastewater surveillance was introduced in Ahmedabad, India, after the successful containment of the first wave of COVID-19 to predict the resurge of the infection during the second wave of the pandemic. The increasing number of positive influent samples correlated with the number of confirmed clinical cases. It also showed clear evidence of early detection of the second wave of COVID-19 in Ahmedabad. We further put forward the wastewater surveillance-based city zonation for effective COVID-19 pandemic preparedness. An eight-month data of Surveillance of Wastewater for Early Epidemic Prediction (SWEEP) was generated for the Ahmedabad, Gujarat, India. Influent wastewater samples (n=287) were analyzed weekly to detect SARS-CoV-2 RNA from nine locations during September 2020 to April 2021. A total of 258 out of 287 samples were detected positive with at least two out of three SARS-CoV-2 genes (N, ORF 1ab, and S). Monthly variation represented a significant decline in all three gene copies in October compared to September 2020, followed by an abrupt increase in November 2020. A similar increment in the gene copies was observed in March 2021, which is an indicator of the second wave of COVID-19. Correspondingly, the descending order of average effective gene concentration was: November (1.1 x 104 copies/L)> April (7.5 x 103 copies/L)> March (4.5 x 103 copies/L)> September (3.0 x 103 copies/L)> December (1.8 x 103 copies/L)> January (1.6 x 103 copies/L)> February (4.7 x 102 copies/L) > October (4.5 x 102 copies/L). A lead of 1-2 weeks was observed in the percentage change in gene concentration with respect to the confirmed cases. Th study highlighted the effectiveness of wastewater surveillance as a tool to predict various waves of the pandemic, to identify the hotspots within the city, and to instigate better implementation of the management interventions.
Subject(s)
COVID-19ABSTRACT
The present study tracked the city-wide dynamics of severe acute respiratory syndrome-corona virus 2 (SARS-CoV-2) RNA in the wastewater from nine different wastewater treatment plants (WWTPs) in Jaipur during second wave of COVID-19 out-break in India. A total of 164 samples were collected weekly between February 19th and June 8th, 2021. SARS-CoV-2 was detected in 47.2% (52/110) influent samples and 37% (20/54) effluent samples. The increasing percentage of positive influent samples correlated with the citys increasing active clinical cases during the second wave of COVID-19 in Jaipur. Furthermore, WBE based evidence clearly showed early detection of about 20 days (9/9 samples reported positive on April 20th, 2021) prior to the maximum cases & maximum deaths reported in the city on May 8th, 2021. The present study further observed the presence of SARS-CoV-2 RNA in treated effluents at the time window of maximum active cases in the city even after tertiary disinfection treatments of UV & Chlorine. The average genome concentration in the effluents and removal efficacy of six commonly used treatments; Activated Sludge Treatment + Chlorine disinfection (ASP + Cl2), Moving Bed Biofilm Reactor (MBBR) with Ultraviolet radiations disinfection (MBBR + UV), MBBR + Chlorine (Cl2), Sequencing Batch Reactor (SBR) and SBR + Cl2 were compared with removal efficacy of SBR + Cl2 (81.2%)> MBBR + UV (68.8%) > SBR (57.1%) > ASP (50%) > MBBR + Cl2(36.4%). The study observed the trends & prevalence of four genes (E, RdRp, N, and ORF1ab gene) based on two different kits and found that prevalence of N> ORF1ab >RdRp> E gene, suggested that the effective genome concentration should be calculated based on the presence/absence of multiple genes. Hence, it is imperative to say that using a combination of different detection genes (E, N, RdRp & ORF1ab genes) reduce false positives in WBE. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=131 SRC="FIGDIR/small/21263417v1_ufig1.gif" ALT="Figure 1"> View larger version (40K): org.highwire.dtl.DTLVardef@156126corg.highwire.dtl.DTLVardef@1d39404org.highwire.dtl.DTLVardef@19a9dcdorg.highwire.dtl.DTLVardef@1ee3a0c_HPS_FORMAT_FIGEXP M_FIG C_FIG HighlightsO_LISuccessful application of WBE with prediction of 14-20 days for COVID-19 in Jaipur C_LIO_LIA comparison of SARS-CoV-2 RNA removal efficacy of 9 WWTPs was investigated C_LIO_LISBR showed better performance than MBBR with SARS-CoV-2 RNA removal from wastewater C_LIO_LIPresence of SARS-CoV-2 in effluents even after UV and Chlorine disinfection C_LIO_LIUsing a combination of different detection genes reduce false positives in WBE C_LI