Coronavirus concentration in waste water is moderate almost throughout Estonia

This week’s waste water analysis shows that over the week, the coronavirus has spread more evenly across Estonia. There are no settlements with extremely large virus amounts on the map but the number of places with small virus amounts has decreased.

According to Tanel Tenson, the lead researcher of the study and Professor of Technology of Antimicrobial Compounds at the University of Tartu, the coronavirus amount is somewhat bigger in Harju county and in southern Estonia compared to the average situation in Estonia. This week, waste water samples were taken both from large and smaller settllements, from a total of 60 sites. “The results show that the virus is spreading more rapidly in larger populated places. In smaller places, the situation remains mostly calm,” 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 for estimating 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 in 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