Waste water analysis map is turning red

The most recent results of the waste water analysis led by the University of Tartu show that the number of people infected with coronavirus continues to grow rapidly in the coming weeks. The situation is becoming particularly serious in Ida-Viru County, where the virus levels have risen to a record high.

The number of samples indicating a very wide spread of the virus is the highest than ever. According to the lead researcher of the study, Professor of Technology of Antimicrobial Compounds of the University of Tartu Tanel Tenson, the map of waste water surveillance shows that the centre of gravity of the spread of the virus is shifting to Ida-Viru County. "The situation has become pretty bad rather quickly. If the data of the Health Board show that Ida-Viru County has reached the level of Tartu County this week in terms of the number of infections, we can expect an even sharper rise in the coming weeks, as such a large amount of virus has not been found in samples before," said Tenson. The coming weeks will not bring relief to southern Estonia, either, where the virus levels have increased again compared to the last few weeks. The situation is somewhat calmer only in western Estonia and the islands.

"The current spread of the virus reflects the aggressive nature of the Delta strain. The virus is spreading fast because a substantial share of the population does not have antibodies. The fastest way to stop this attack is vaccination," emphasised Tenson.

How are the samples collected?

Waste water 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 waste water passing through the treatment plant over 24 hours, giving a reliable overview of the infection level in the city.  The spot samples taken in smaller places show 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 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 the collection of samples, the University of Tartu cooperates with the Estonian Environmental Research Centre and water companies operating the 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 of the University of Tartu, tanel.tenson@ut.ee, 5344 5202,