A new role for ANSES in monitoring SARS-CoV-2 in wastewater

ANSES's Laboratory for Hydrology has been appointed National Reference Laboratory for the monitoring of SARS-CoV-2 in wastewater and sewage sludge, by the Ministries of Health and Ecological Transition. Its responsibilities include harmonising the methods used to detect the virus and assessing the abilities of the laboratories tasked with carrying out the analyses.

Monitoring the presence of SARS-CoV-2 in wastewater serves to indirectly track the spread of the virus and its variants in the population. "Instead of having to screen several hundred people, we can use a single regular test to find out whether the virus is present in a geographical area," explains Christophe Cordevant, scientific advisor at ANSES. "Sewage sludge, which is the result of wastewater treatment in sewage treatment plants, is more concentrated and could enable the virus to be detected in situations where it is imperceptible in wastewater.

In March this year, the European Commission recommended that each Member State establish a surveillance system for SARS-CoV-2 in wastewater. This surveillance is designed to supplement the tools already available, particularly in a context of low viral circulation, in order to detect the virus's (re)emergence in the population at an early stage. 

Several research projects were launched in France during 2020 on detecting the virus responsible for COVID-19 in wastewater.  In order to improve the quality of the surveillance system, ANSES, and more specifically its Nancy Laboratory for Hydrology, has been appointed National Reference Laboratory (NRL) for the monitoring of SARS-CoV-2 in wastewater and sewage sludge. 

Guaranteeing the quality of analyses

The tasks of the NRL are primarily to ensure the reliability of the data obtained from surveillance by harmonising the methods used, from sampling through to data analysis and standardisation. This is largely based on standardisation work carried out by AFNOR. The NRL will provide the laboratories responsible for the analyses with assistance on the recommended practices, and assess their ability to implement the detection systems through inter-laboratory proficiency tests. It will also be involved in developing the surveillance plans drawn up by Santé Publique France. 
At European and international level, the NRL may also participate in working groups on SARS-CoV-2 surveillance methodologies. Lastly, it will continue its research, in particular to acquire knowledge on the persistence of this virus in wastewater or sewage sludge. 

A network for monitoring SARS-CoV-2 in water

Nationwide implementation of this standardised monitoring of the virus will be supported by the SUM'EAU network (microbiological surveillance of wastewater), which involves the Directorate General for Health, the Directorate for Water and Biodiversity, Santé Publique France and ANSES. The monitoring sites are still being determined, but they are expected to include cities with more than 150,000 inhabitants, and other strategic locations such as airports.