Map reflecting coronavirus concentration in waste water is turning greener

The newest results of the waste water monitoring survey led by the University of Tartu show a continuing decrease in the coronavirus amount in wastewater. Only the results of Ida-Viru County considerably differ from the general picture: the virus level there is five times higher than the average in Estonia.

According to the principal investigator of the study, Professor of Technology of Antimicrobial Compounds of the University of Tartu Tanel Tenson, the number of places with low virus concentration in waste water has significantly increased. “The percentage of places with low concentration of the virus is currently comparable to the level in the autumn,” Tenson said.

How and where are the samples collected?

Wastewater samples are collected at the beginning of every week in all county centres, cities with more than 10,000 inhabitants and, if necessary, in smaller settlements. Samples taken from larger cities reflect the situation of wastewater 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 situation at the moment of sampling. Spot samples are more easily affected by various factors and should therefore be used in comparison over several weeks to estimate the trend, rather than to 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 of Estonian cities. The samples are analysed at the laboratories of the University of Tartu Institute of Technology.

For more information and the interactive map with 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