Detected coronavirus variants in wastewater

Wastewater monitoring can determine variations in the proportions of different coronavirus variants in Finland. 

The coronavirus RNA levels are currently examined on a weekly basis in nine localities: at the wastewater treatment plants in Espoo, Helsinki, Joensuu, Jyväskylä, Kuopio, Oulu, Tampere, Turku and Vaasa.

Wastewater samples in which coronavirus RNA is detected are sent for sequencing in order to determine the coronavirus variants. The results of sequencing are reported to this page as soon as the results are available, usually after 2–4 weeks from sample collection.

Variants with asterisks in the graphs also contain their sublineages.

Graph 1. Coronavirus variants in Finnish wastewater from 3 January 2022.
 

Total proportions of different SARS-CoV-2 virus variants in Finnish wastewater samples from monitored wastewater treatment plants. At the beginning of 2022, the Omicron BA.1 subvariant was the most common until March 2022, when Omicron BA.2 became the most common subvariant. BA.2 was the most common subvariant until the end of June 2022, when the Omicron BA.5 subvariant became the most common one. At the end of November 2022, the Omicron BQ.1 subvariant began to become more common. Omicron XBB variant started to become more common in January 2023. In August 2023, EG.5 became the most common variant. BA.2.86 variant was detected for the first time in October 2023. JN.1*, a sublineage of BA.2.86, became the most abundant variant in wastewater in the beginning of 2024. Currently, it is the only variant detected in wastewater.
Total proportions of different SARS-CoV-2 virus variants in Finnish wastewater samples from monitored wastewater treatment plants. The lighter-shaded area represents the standard deviation from the results of different treatment plants.

Graph 2. Coronavirus variants in Finnish wastewater by wastewater treatment plant from 3 January 2022.
Total proportions of different SARS-CoV-2 virus variants in Finnish wastewater found in sequenced samples from monitored wastewater treatment plants.

Total proportions of different SARS-CoV-2 virus variants in Finnish wastewater found in sequenced samples from monitored wastewater treatment plants. The lighter-shaded part of the image depicts standard deviation between the proportions of different mutations. 

Further information

Coronavirus variants in wastewater

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