Results

Phase 1 – Development and optimization of work protocols for the detection of SARS-CoV-2 and circulating variants in untreated wastewater (June 21, 2022, to December 31, 2022).

During this stage, work protocols were developed and optimized for the concentration of viral particles, extraction of genetic material, and quantification of total SARS-CoV-2 viral RNA in untreated wastewater samples. Additionally, in collaboration with the partner institution, INCD-ECOIND, both the strategy for collecting untreated wastewater samples and the locations, frequency, and necessary volume for subsequent molecular biology analyses and determination of physico-chemical parameters were established. Thus, with all optimized protocols available, the monitoring campaign of untreated wastewater in Bucharest was initiated. Initial results demonstrate the presence of SARS-CoV-2 viral particles in untreated wastewater in Bucharest at all collection times, in locations serving extensive areas or with a high number of infected individuals/surface (~10⁶ copies/L). The total concentration of SARS-CoV-2 in untreated wastewater shows a similar trend to clinical data provided online by public health authorities. The results obtained in the first stage of the project are promising and represent the starting point for what is intended to be a monitoring campaign of untreated wastewater correlated with epidemiological data – the implementation of an early epidemiological warning system for SARS-CoV-2 trends in untreated wastewater.