Monitoring SARS-CoV-2 Dissemination in Wastewater and Virus Isolation in Cell Cultures: An Integrated Approach for...

Our study presents wastewater (WW) monitoring data, focusing on determining the infectivity of SARS-CoV-2 in the collected samples. Additionally, a panel of different viruses has been tested in the WW samples. The untreated WW monitoring campaign took place over 1 year in Bucharest, with approximately 300 samples being collected twice a week at the wastewater treatment plant (WWTP) and an infectious diseases hospital. Our data indicated that SARS-CoV-2 concentrations in WW preceded the increase in the number of clinical cases by nearly 2 weeks. Differences between locations were notable, with higher raw concentrations in WW samples from the hospital than those from the WWTP. However, after normalising to population equivalent, the hospital samples concentrations dropped significantly, suggesting that WW monitoring at the urban level provides a more complete and epidemiologically relevant picture than data obtained only from hospitals. Only a few isolates could demonstrate SARS-CoV-2 persistence during in vitro passages. Although the success rate was low, the technique remains crucial for validating the viability of viruses. Adenovirus, Bocavirus and Reovirus were the most abundant ones in both urban and hospital wastewater. WW monitoring remains the most effective approach for tracking the dissemination of various pathogens and supporting public health authorities.