The latest results of the study led by the University of Tartu confirm a decrease in coronavirus amounts in waste water all over Estonia. There are no very large virus amounts in any settlement.
While just a week ago the interactive map of surveillance results still displayed several places in dark red, which referred to very high virus amounts, the results of the recently ended stage of the study are marked in green or yellow in nearly all places. This shows a predominantly small or moderate level of coronavirus in waste water. According to the principal investigator of the study, Professor of Technology of Antimicrobial Compounds of the University of Tartu Tanel Tenson, the decrease is also evident in the cities of Ida-Viru county, where the previously persistently very high virus concentrations have now reached a moderate level.
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 [ät] ut.ee