The COVIDETECT project started 3 months ago. The first results confirm the presence of the virus in sewage and that it is eliminated in waste water treatment plants (WWTP). More than 200 samples of wastewater collected at the entry and exit of treatment plants that serve about 20% of the national population and areas with a high prevalence of infections were analysed. The results are in line with those obtained in other similar international studies. The results of the project were released by Águas de Portugal (AdP), which coordinates the project consortium, and allow to verify the absence of SARS-CoV-2 virus genetic material in the treated wastewater in the five WWTPs involved in this study”, which suggests that the treatment steps are efficient” in removing the virus from sewage.
The Analysis Laboratory at IST (LAIST) is part of this consortium. Ricardo Santos and Sílvia Monteiro, LAIST researchers and team leaders, developed and validated the detection method that allows to analyse wastewater.
It is important to note that, as mentioned in the press release, the detection of the genetic material of the virus in wastewater at the entrance of the WWTP does not mean that the virus is active and that it can be spread in water.
The WWTP included in the first phase of this study are located in Lisbon, Cascais, Gaia and Guimarães, serving about 20% of the total national population and covering the regions with the highest number of COVID-19 cases. Additionally, and in order to monitor the circulation of the virus, the effluents of Hospital Curry Cabral (Lisbon), Hospital Eduardo Santos Silva (Vila Nova de Gaia), and Hospital Senhora da Oliveira (Guimarães) are discharged into sewer networks.
COVIDETECT intends to implement an early warning system through the surveillance of sanitation systems, which may contribute to the mitigation of an eventual new outbreak of the disease. The Faculty of Sciences at Universidade de Lisboa (FCUL), Águas do Tejo Atlântico, Águas do Norte and SIMDOURO join this consortium as management entities of the largest urban drainage systems. The Directorate-General for Health (DGS), the Portuguese Environment Agency (APA) and the Portuguese Water and Waste Services Regulation Authority (ERSAR) are members of COVIDETECT advisory board.
The results of COVIDETECT can be extremely important for the epidemiological surveillance of the population, indirectly. As mentioned in the press release “wastewater is a good indicator of the presence of the virus in a community, therefore the results of this project can be replicated on a broader scale”. “In addition, the virus excretion occurs several days before infected persons have developed symptoms, so the implementation of this early warning tool can ensure a timely implementation of preventive public health measures in the geographic location of the populations under study”.
