Dashboards
As of June 2023, the SARS-CoV-2 data will no longer be updated by SEEC-KTH. Data from after June 2023 is available from other research groups.
Amount of SARS-CoV-2 in wastewater (SEEC-KTH)
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 dedicated page. SEEC-KTH is now part of the Department of Industrial Biotechnology at KTH.
The data and visualisations on this page are no longer being updated as of June 2023. This dashboard combines data from two periods:
- Recent period (September 2021 - June 2023): Data collected using the Promega kit for concentration, starting from week 35 of 2021.
- Historic period (April 2020 - August 2021): Data collected using the initial concentration method based on earlier studies.
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 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.
Recent data (September 2021 - June 2023)
This section displays data from September 2021 onwards, when the method was changed to use the Promega kit for concentration. Data collection ceased in June 2023.
Recent methods
Starting from week 35 of 2021, the group began to use the Promega kit for the concentration step. 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.
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
Last updated: June 2023 (no longer updating)
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Malmö
Last updated: June 2023 (no longer updating)
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Recent 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.
Historic data (April 2020 - August 2021)
This section displays data on the amount of SARS-CoV-2 in the wastewater in Stockholm between April 2020 and August 2021. The amount of SARS-CoV-2 in wastewater was calculated as the number of gene copies per week (raw wastewater) with bovine + PMMoV factor. From September 2021 onwards, the method was changed. Please see the Recent data section above for data from September 2021 onwards.
Historic methods
After concentration, filtering, and preparation, the samples are analysed using qPCR to test for SARS-CoV-2 RNA. Primers of the nucleocapsid (N) gene (previously used and verified by Medema et al. (2020)) were used to detect SARS-COV-2. In some cases, samples of raw wastewater were frozen at –20oC, and concentrated wastewater or purified RNA were stored at -80oC before the next analysis step was carried out. The concentration method used by prof. Gurol and colleagues was based on their published study (Jafferali et al., 2021), in which they compared four different concentration methods. The study concluded that the double ultrafiltration method adapted by KTH was significantly more efficient than single filtration and adsorption methods. Please see Jafferali et al. (2021) for more information on the methods. More information about data summaries and preliminary conclusions are also available.
Historic visualisation - Stockholm
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All samples up until week 21 of 2020 were received by the lab in week 21. Between weeks 21 and 33 of 2020, samples were analysed biweekly. After week 33 of 2020, samples were typically analysed weekly, although measurements were taken fortnightly, rather than weekly, between weeks 24 and 32 of 2021.
Historic dataset
Download the data: Gene copy number/week (raw wastewater) with bovine + PMMoV factor; Excel file. The numbers for Stockholm overall, and for the Henriksdal, Sickla, Hässelby, Järva, Riksby, and Käppala inlets are provided. At least partial data are available between week 16 of 2020 and week 34 of 2021.
How to cite:
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
This dashboard combines data from two periods with different methodologies. The method changed in September 2021 (week 35 of 2021) when the group began using the Promega kit for concentration. Below, we explain both methods.
Recent methods (September 2021 - June 2023)
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.
Starting from week 35 of 2021, the group began to use the Promega kit for the concentration step. 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.
Historic methods (April 2020 - August 2021)
After concentration, filtering, and preparation, the samples are analysed using qPCR to test for SARS-CoV-2 RNA. Primers of the nucleocapsid (N) gene (previously used and verified by Medema et al. (2020)) were used to detect SARS-COV-2. In some cases, samples of raw wastewater were frozen at –20oC, and concentrated wastewater or purified RNA were stored at -80oC before the next analysis step was carried out. The concentration method used by prof. Gurol and colleagues was based on their published study (Jafferali et al., 2021), in which they compared four different concentration methods. The study concluded that the double ultrafiltration method adapted by KTH was significantly more efficient than single filtration and adsorption methods. Please see Jafferali et al. (2021) for more information on the methods. More information about data summaries and preliminary conclusions are also available.
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).