NATIONAL SURVEILLANCE OF SARS-COV-2 IN WASTEWATER - How does WBE contribute to the global epidemiologic assessment in Belgium? (September 2020 – 2024)

Monitoring coronavirus (SARS-CoV-2) via wastewater analysis enables early detection of the evolution of the viral circulation in a population, since people infected by COVID-19 excrete particles of SARS-CoV-2 in wastewater. The circulation of SARS-CoV-2 in the Belgian population is monitored since September 2020 by taking 24h-representative samples at the inlet of 42 wastewater treatment plants twice a week.
The present report presents the COVID-19 wastewater-based epidemiology surveillance between February 2021 and December 2023 and how it was used to assess the global epidemiological (EPI) situation in Belgium during this period. The population covered by this program represents 42% of the Belgian population.
The results presented in this work demonstrate that satisfying correlation levels were observed at the implementation and running stages of the present surveillance, which were used as a proof of concept for validating our tool, especially at the time where the testing capacity was high. Also, a preceding character was evidenced in several areas and is discussed in a dedicated section of the present report. Finally, results show the added value of the wastewater-based surveillance to other existing systems (e.g. case-based incidence) for the detection of any significant resurgence in the viral circulation, as well as the reaching of a circulation peak. A “respiratory bulletin” is published weekly assessing the respiratory virus situation by integrating wastewater data with conventional surveillances (hospitalization, case, nursing home, etc.).