Joshi, MadhviMadhviJoshiKumar, ManishManishKumarSrivastava, VaibhavVaibhavSrivastavaKumar, DineshDineshKumarRathore, Dalip SinghDalip SinghRathorePandit, RameshRameshPanditGraham, David W.David W.GrahamJoshi, Chaitanya G.Chaitanya G.Joshi2025-08-312025-08-312022-10-0110.1016/j.envpol.2022.1197572-s2.0-85135954035http://repository.iitgn.ac.in/handle/IITG2025/2591635853573Wastewater-based genomic surveillance can identify a huge majority of variants shed by the infected individuals within a population, which goes beyond genomic surveillance based on clinical samples (i.e., symptomatic patients only). We analyzed four samples to detect key mutations in the SARS-CoV-2 genome and track circulating variants in Ahmedabad during the first wave (Sep/Nov 2020) and before the second wave (in Feb 2021) of COVID-19 in India. The analysis identified a total of 34 mutations in the spike protein across samples categorized into 23 types. The spike protein mutations were linked to the VOC-21APR-02; B.1.617.2 lineage (Delta variant) with 57% frequency in wastewater samples of Feb 2021. The key spike protein mutations were T19R, L452R, T478K, D614G, & P681R and deletions at 22029 (6 bp), 28248 (6 bp), & 28271 (1 bp). Interestingly, these mutations were not seen in the samples from Sep/Nov 2020 but did appear before the massive second wave of COVID-19 cases, which in India started in early April 2021. In fact, genetic traces of the Delta variant were found in samples of early Feb 2021, more than a month before the first clinically confirmed case of this in March 2021 in Ahmedabad, Gujarat. The present work describes the circulating of SARS-CoV-2 variants in Ahmedabad and confirms the consequential value of wastewater surveillance for the early detection of variants of concerns (VOCs). Such monitoring must be included as a major component of future health protection systems.falseCOVID-19 | Detection | India | Mutation | SARS-CoV-2 | Wastewater surveillanceArticlehttps://www.ncbi.nlm.nih.gov/pmc/articles/9287018187364241 October 202222119757arJournal23WOS:001139075300001