Waste water study confirms an even spread of the coronavirus throughout Estonia

This week’s results of the waste water monitoring study led by the University of Tartu show that the virus has spread evenly all over Estonia.  In southern Estonia, the virus amounts have somewhat decreased, while in central Estonia the number of settlements with high virus concentration has grown. The island of Hiiumaa remains free of the coronavirus.

Tanel Tenson, the lead researcher of the study, Professor of Technology of Antimicrobial Compounds at the University of Tartu, appreciates the fact that the recent weeks have not shown a marked increase in virus amounts. In southern Estonia, the coronavirus level is still slightly higher than the index describing the average situation in Estonia, but the situation has somewhat improved compared to last weeks. At the same time, the virus concentration has grown in several settlements of central Estonia and in Pärnu County. “The results suggest that in the coming weeks, the increase in new infection cases will be quite similar to the current situation,” Tenson explained.

How and where are the samples collected?

Waste water samples are collected at the beginning of every week in all Estonian county centres, cities with more than 10,000 inhabitants and, if necessary, in smaller settlements. Samples taken from larger cities reflect the situation of waste water passing through the treatment plant over 24 hours, giving a reliable overview of the infection level in the city. In smaller places, spot samples are taken, showing the virus level in waste water at the moment of sampling. Spot samples are more easily affected by various factors and should therefore be used over several weeks to estimate the trend rather than get a definitive picture of the current situation.

The study is a tool helping the Health Board monitor changes in the outbreak dynamics and discover hidden outbreaks. It gives early information to estimate the spread of the virus before clinical cases are detected. The Health Board is regularly informed of the results.

In collecting the samples, the University of Tartu cooperates with the Estonian Environmental Research Centre and water companies operating the waste water treatment plants of Estonian cities. The samples are analysed at the laboratories of the University of Tartu Institute of Technology.

For more information about the previous results of the study, see the home page of the study “Detecting coronavirus in waste water”.

Further information: Tanel Tenson, Professor of Technology of Antimicrobial Compounds, University of Tartu, 5344 5202, tanel.tenson@ut.ee