Introduction
This project is led by associate professor Zeynep Cetecioglu Gurol and supported by Mariel Perez-Zabaleta and Isaac Owusu-Agyeman at KTH Royal Institute of Technology (KTH). Bioinformatics analyses of wastewater samples are held by assistant professor Luisa Hugerth (Uppsala University). This group of researchers are known as SEEC-KTH. The project was established as a collaboration between the SciLifeLab COVID-19 National Research Program, and the SEED and Chemical Engineering departments at KTH. The project is now funded as part of the SciLifeLab Pandemic Laboratory Preparedness (PLP) Program. More information about the PLP program can be found in our resources section. SEEC-KTH is now part of the Department of Industrial Biotechnology at KTH.
The data and visualisations on this page are usually updated weekly, typically on Fridays. Data and information about the group on this dashboard are updated frequently, so please check back regularly to stay up to date.
Wastewater collection sites
The analysis of wastewater samples from Stockholm by SEEC-KTH is done in close collaboration with Stockholm Vatten och Avfall, and the Käppala Association. SEEC-KTH began to sample wastewater in mid-April 2020, and samples were collected from the Bromma, Henriksdal, and Käppala wastewater treatment plants. These plants receive wastewater from a population of approximately 360,000, 860,000, and 500,000 people, respectively. Please consult this map for the exact catchment area of the wastewater collection channels in Käppala and this map for the exact catchment area of the wastewater collection channels in Bromma and Henriksdal.
SEEC-KTH began to collect and wastewater samples from the Sjölunda wastewater treatment plant in Malmö in week 39 of 2021. This wastewater plant services the majority of Malmö, as well as the Burlöv municipality and parts of the municipalities of Lomma, Staffanstorp, and Svedala. Around 300,000 people live in the catchment area of this wastewater treatment plant. More information about the catchment area, including a map, can be downloaded directly.
Overall, SEEC-KTH analyse wastewater from around 20% of the population of Sweden.
Visualisations
Please note that the visualisations below show data for the most recent 16 weeks for which data are available by default. It is possible to see all of the data by clicking the ‘Whole timeline’ button.
Please also note that although the same methods are used for all cities shown on this tab, differences in the wastewater collection systems and populations of different cities might bias direct comparisons between cities.
Stockholm
Code used to produce plot: Script to produce plot.
Malmö
Code used to produce plot: Script to produce plot.
Commentary from the research group
Commentary:
Dataset
Download the data: N3-gene copy number per PMMoV gene copy number; Excel file. Results are available (partially) starting from week 16 of 2020 for Stockholm and starting from week 39 of 2021 for Malmö; updated weekly.
Contact: zeynepcg@kth.se
How to cite dataset: Cetecioglu, Z. G., Williams, C., Khatami, K., Atasoy, M., Nandy, P., Jafferali, M. H., Birgersson, M. (2021). SARS-CoV-2 Wastewater Data from Stockholm, Sweden. https://doi.org/10.17044/scilifelab.14315483.
Methods
To correct for variations in population size and wastewater flow, the group quantifies the pepper mild mottle virus (PMMoV) using a modified version of the assay of Zhang et al. (2006). PMMoV is an abundant RNA virus in human faeces and serves as an estimator of human faecal content (Symonds et al., 2019). SARS-like virus specific N3-primers (Lu et al., 2020) with SYBR Green chemistry (Perez-Zabaleta et al., 2023) are used to quantify SARS-CoV-2.
After concentration, filtering, and preparation, the samples are analysed using the qPCR technique for SARS CoV-2 RNA. Primers of the nucleocapsid (N) gene were used to detect the SARS-COV-2 gene (previously used and verified by Medema et al. (2020)). In some cases, raw wastewater samples were frozen at -20℃, and concentrated wastewater or purified RNA samples were sometimes stored at -80℃ before the next analysis step was carried out. The concentration method initially used by SEEC-KTH was based on one of their earlier studies (Jafferali et al., 2021), which compared four different concentration methods. This method was used until week 35 of 2021. After this time, the group began to instead use the Promega kit for the concentration step.
Archived data
Related data
- SARS-CoV-2 variant analysis from wastewater (data available in the European Nucleotide Archive (ENA) under project number PRJEB60156): The group at KTH analysed samples from Stockholm and Malmö (2021-2022).