THL adds 6 new cities to coronavirus wastewater monitoring

The National Institute for Health and Welfare (THL) is expanding coronavirus wastewater monitoring, said an official press release on Tuesday.

The new wastewater treatment plants included in the most recent sampling round were Kuopio, Vaasa, Pori, Joensuu, Kouvola and Hämeenlinna.

In the latest sampling, carried out from 15 to 17 August, the coronavirus genome was detected in samples from all the treatment plants.

The genome quantities observed were lower, however, in many localities. Two areas which saw an increase were Jyväskylä and Oulu.

The weekly monitoring has been carried out at the wastewater treatment plants in Helsinki, Espoo, Turku, Tampere, Oulu and Jyväskylä. In addition, a fortnightly samples have been taken at Lappeenranta and Rovaniemi.

“The scope of wastewater monitoring needs to be increased again to provide demographic information on regional changes in the coronavirus situation,” said Chief Specialist Carita Savolainen-Kopra from THL.

The revised wastewater monitoring report has new technical features which help with comparing the results to the number of coronavirus cases observed in individual testing in the different regions.

The increase in infection rates can be seen in the results of the wastewater monitoring. For example, the wastewater samples collected from Viinikanlahti in Tampere in June and July produced several results that remained below the determination limit, meaning that only small amounts of the RNA genome of coronavirus were detected. Towards the end of July and through early August, however, the genome quantities have risen to record levels.

“The same trend can also be seen at other wastewater treatment plants that are part of the monitoring,” said Researcher Anna-Maria Hokajärvi from THL.

Tracking changes in the quantities of coronavirus genome in wastewater supports ongoing monitoring of the changing epidemic situation

From now on, the reporting on wastewater monitoring will monitor more closely the change in the numbers of coronavirus genome copies in each wastewater treatment plant over each two-week monitoring period.