The spread of coronavirus is increasing in wastewater again, the University of Tartu's weekly study shows. The increase is now highest in southern and western Estonia.
While last week's analysis showed a fall in quantities of the virus detected in wastewater, this week the concentration is at a two week high.
Lead researcher, Professor of Technology of Antimicrobial Compounds at the University of Tartu, Tanel Tenson said last week's optimism was premature.
"Virus quantities have grown everywhere in Estonia, and thus it is definitely reasonable to continue with the current restrictions," he said.
From this week, the results map also includes samples taken from smaller settlements. The results - "grab samples" - from these smaller areas reflect the level of coronavirus at the time of sampling, while samples from large cities show a 24 average.
"Grab samples are highly influenced by whether infected people have used the toilet around the time of sampling. Thus, it is necessary to monitor and compare the results from smaller communities over several weeks to assess whether the number of infections is growing or the outbreak is subsiding," Tenson said. "In grab sampling, results confirming the presence of virus are probably reliable. However, a single grab sample with no virus may not always mean that there are no infections in the community."
For more information and the interactive map with the previous results of the study, see the home page of the study "Detecting coronavirus in wastewater".
The monitoring helps to find hidden outbreaks and monitor changes in the dynamics of outbreaks. Coronavirus can be detected in wastewater before symptoms show and outbreaks appear.
On Thursday, Prime Minister Kaja Kallas (Reform) said Estonia's infection rate - R - was 0.85, the lowest for several months. If the wastewater results continue to show an upward trend, it can be expected that the infection rate will also rise.
The most recent results map, above, shows that the majority of cities in Estonia are now colored red, indicating the highest concentration level of coronavirus.
Kärdla, Haapsalu, Pärnu, Tallinn, Viimsi-Muuga, Rapla, Rakvere, Jõgeva, Tartu, Põlva, Võru, Kohtla-Järva, Ahtme, Sillamäe and Narva are now all red. Paide, Viljandi and Valga are yellow and only Kuressaare on the island of Saaremaa has a good rating.
In comparison, last week (below), Kärdla, Haapsalu, Tallinn, Viimsi-Muuga, Rakvere, Järve, Ahtme and Narva had the highest levels of virus.
Rapla, Rakvere, Jõgeva, Pärnu, Võru, Põlva and Sillamäe have worsened over the week, while the situation has improved in Kuressaare.
Editor: Helen Wright