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

Srivastava, Vaibhav; Gupta, Shilangi; Patel, Arbind Kumar; Joshi, Madhvi; Kumar, Manish

Wastewater-based epidemiology (WBE) is a promising approach to understand the actual prevalence of COVID-19 disease at the community level. Different studies have cited the presence of SARS-CoV-2 in wastewater samples. In the present study, eighteen influent wastewater samples from different wastewater treatment plants and pumping stations (5 samples from Vadodara city, 4 from Gandhinagar, and 9 from Ahmedabad city) were collected and analyzed for the occurrence of SARS-CoV-2 RNA in Gujarat province, India. The results showed the highest SARS-CoV-2 effective gene concentration in Vadodara (3078 copies/L), followed by Ahmedabad (2968 copies/L) and Gandhinagar (354 copies/L). On comparing the virus gene concentration in three cities, the SARS-CoV-2 genetic material exhibited a positive relationship with the number of confirmed and active cases in Gandhinagar. However, a minor variation in SARS-CoV-2 genetic material was seen between Vadodara and Ahmedabad despite a two-fold difference in the number of confirmed cases. This may occur primarily due to the greater test positivity rate in Vadodara (3.30%) than Ahmedabad (1.40%) and might be the higher number of asymptomatic patients. The study confirms the potential of the WBE that can be used at a large scale around the globe for better dealing with the pandemic situation.