Campus Sewage Water Surveillance based dynamics and infection trends of SARS-CoV-2 variants during third wave of COVID-19 in Pune, India

The wastewater-based epidemiology (WBE) of SARS-CoV-2 is a quick and cost-effective method of tracking virus transmission. However, few studies reported on campus or in academic or residential settings worldwide. In this study, we demonstrated the WBE approach to detect, monitor, and evaluate genomic variants of SARS-CoV-2 fragments in a sewage treatment plant (STP) located on the campus of CSIR National Chemical Laboratory, Pune, India. Herein we describe the early warning capability of WBE, with viral load rise in campus sewage water up to 14 days before its clinical detection. This was supported further by a significant correlation between SARS-CoV-2 RNA concentration and clinically reported COVID-19 cases on campus. Additionally, we comprehended the probable targets missed by the quantitative qRT-PCR using amplicon-based sequencing due to low viral load. The analysis revealed the presence of signature mutations of the Omicron (S:N679K, S:N764K, S:D796Y, N:P13L, ORF1a:T3255I, ORF1a:K856R, ORF1a:P3395H, and N:S413R) before the lineage was first detected globally. Further, we used Lineage decomposition (LCS) tool to detect the Variant of Concern (VOC)/Variant of Interest (VOI) signals upto a month earlier in sewage water samples. The analysis also indicated the transition of lineage from Delta to Omicron in late Decemeber,2021. This is the first study in India highlighting the use of on-campus STP to evaluate the local spread of SARS-CoV-2, which could aid in preventing COVID-19 in academic institutes/universities. This study proves the usefulness of WBE as an early warning system for detecting, tracking and tracing VOCs using the sequencing approach. The current study could aid in taking critical decisions to tackle the pandemic scenario on campus. HighlightsO_LIThe first study on campus sewage water for SARS-CoV-2 surveillance in India C_LIO_LIEarly detection of Omicron VOC signals during early November 2021 C_LIO_LISequencing revealed the presence of Omicron VOC fragments prior to clinical cases reported on campus C_LIO_LIGenomic analysis indicated transition of Delta to Omicron lineage in late December 2021 and potentially led to the third wave C_LIO_LICombining qRT-PCR and sequencing could be useful for on-campus tracking of variants using wastewater surveillance C_LI