Researchers from IMDEA Water have published a study on the presence and amount of genetic material (RNA) from the SARS-CoV-2 virus, responsible for the COVID-19 pandemic, in wastewater. The study, published in the journal Scientific Reports, has been carried out over a year in a sewage treatment plant in the Community of Madrid.
Most of the methods for the detection and quantification of SARS-CoV-2 RNA in wastewater describe three steps: concentration, RNA extraction and detection and quantification by RT-qPCR (Fig 1). For this study, another step was added before the concentration, a pre-treatment, reducing the amount of organic matter present, abundant in wastewater. This previous step improved both the detection level and the quantification of genetic material of SARS-CoV-2 from samples.
Data obtained allowed obtaining information on the evolution of the pandemic, detecting whether there were changes, an increase or decrease, or not in the presence of genetic material of the virus over a year. These analyses detected increases in the presence of virus RNA that corresponded to the different epidemiological waves.
Figure 1. Scheme of the process for the detection and quantification of SARS-CoV-2 RNA.
This work is a new confirmation of the utility of wastewater analysis to know the situation and evolution of the COVID-19 pandemic, and the benefit of its analysis as an early warning system, not only against this virus, but also against future epidemics due to other microorganisms.
This work was performed thanks to a collaboration agreement with Canal de Isabel II.
1. Peinado, B., Martínez-García, L., Martínez, F., Nozal, L. and Sánchez M.B. Improved methods for the detection and quantification of SARS-CoV-2 RNA in wastewater. Sci Rep 12, 7201 (2022). https://doi.org/10.1038/s41598-022-11187-8