SARS-CoV-2 Detected in Wastewater across Luxembourg, Increased Presence in South

The latest results of a study by the Luxembourg Institute of Science and Technology (LIST) have revealed that SARS-CoV-2 can now be found in almost all wastewater in the Grand Duchy, with a sharp increase in concentration observed in the south of the country.

As of 14 July 2020, the latest results of LIST's CORONASTEP+ study indicated the presence of SARS-CoV-2 (COVID-19) in almost all of the sites sampled: from Bettembourg to Schifflange, as well as Beggen. Only samples from the Troisvierges site appeared negative.

Since 25 June 2020, a resurgence of SARS-CoV-2 has been observed in the country's wastewater. This development, along with an increase in the number of positive cases, confirms the high sensitivity and interest in LIST’s methodology for coronavirus surveillance in Luxembourg.

LIST’s latest report also showed a sharp increase in RNA (Ribonucleic acid) concentration of SARS-CoV-2 in treatment plants in Luxembourg. In other words, characteristic segments of the genetic identity card of this coronavirus are found in higher concentrations.

The Bettembourg and Pétange wastewater treatment plants appeared to be the most affected, with an almost tripled increase in concentration since June. Conversely, the sites in Hesperange and in the north of the country have seen a lower and more stable concentration over time. However, the method still needs to be refined in order to clarify the significance that can be concluded from small amplitude variations in SARS-CoV-2 RNA concentrations.

These observations corroborate the evolution of the number of cases confirmed by clinical tests carried out on a large scale in the Grand Duchy and confirm that water monitoring method is an effective pre-alert system of virus resurgence in the population, according to LIST.