Fig. 5. Detection of the Delta variant in six Swiss WWTPs.
Detection of the Delta variant in wastewater between January and September 2021 for the WWTPs of Lugano (top left), Laupen (top right), Zürich (middle left), Chur (middle right) and Altenrhein (bottom right), and between January and August 2021 for the WWTP of Lausanne (bottom left). Detection was performed through co-occurrences of signature mutations using COJAC, and compared to clinical sequencing in the cantons where the treatment plants are located. Green and orange bars represent the number of non-Delta and Delta clinical sequences, respectively, from the canton (stacked) for each day in the surveyed period. Blue bars indicate COJAC signals of variant-specific mutation co-occurrences in the wastewater. First detections are indicated by black arrows.