Waste water study: Ida-Viru County experienced the fastest increase in coronavirus level

This week’s results of the waste water monitoring study led by the University of Tartu confirm a continuing increase in coronavirus amounts all over Estonia. Over the week, the largest increase in the number of viruses was observed in the waste water of Ida-Viru County. Virus amounts are predominantly high or very high everywhere in Estonia. 

While last week, the map reflecting the results of the waste water study showed a few cities where no or only few coronaviruses had been found in waste water, this week there are no such places. According to Tanel Tenson, lead researcher of the study and Professor of Technology of Antimicrobial Compounds at the University of Tartu, coronavirus amounts have grown almost everywhere in Estonia, but the biggest change occured in Ida-Viru County where the virus readings were ten times the index representing the average situation in Estonia. “Over the week, we have come yet another step closer to the peak of the previous wave of infections. Our results reveal that in addition to Ida-Viru County, the number of new infections will significantly increase also in Harju County and in central and western Estonia. In southern Estonia, the amount has stabilised at quite a high level,” said Tenson.

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