Record high levels of coronavirus have been detected during the University of Tartu's latest sewage monitoring study which took place during the first week of February.
This week's study revealed a "rapidly increased concentration of the coronavirus" across Estonia.
The Health Board (Terviseamet) said an increase in infections after the restrictions were eased was to be expected, but the wastewater analysis results call for vigilance.
Lead researcher Tanel Tenson, professor of Technology of Antimicrobial Compounds of the University of Tartu, said this week's figures are the highest in the study's history.
A week ago, the number of samples with very high virus concentration was almost equal to samples of medium and low concentrations, now the virus concentration is high in 14 of the 20 sampling sites.
"I can say that our samples have never before shown such a high virus level. The results allow us to deduce that the number of infections has increased a lot almost everywhere in Estonia," Tenson said.
Hanna Sepp, head of the Department of Infectious Diseases Surveillance and Epidemic Control at the Health Board, said while the results are alarming not all everything indicates a surge in infections.
"The number of new COVID-19 cases has been very high in the recent weeks, but rather stable. There is also a persistently high level of positive tests indicating latent spread. Also, the number of people in hospital care has remained on a stable level," Sepp said. After the restrictions were eased, a rise in infections was expected, she added.
"Although the results of this study are not always consistent with the number of COVID-19 cases identified, the study proactively helps us focus our attention and actions, and build preparedness," said Sepp.
On Wednesday new restrictions were applied across the country to curb the spread of the coronavirus.
Wastewater samples are collected every week in all Estonian county centers and cities with more than 10,000 inhabitants. The study gives early information for estimating the spread of the virus before clinical cases are detected. The monitoring helps to find hidden outbreaks and observe changes in the dynamics of outbreaks.
This week's results (above) show a higher concentration of coronavirus in sewage across the country when compared to last week's study (below).
This week, all four monitoring sites in Ida-Viru county are above 2,000 viruses per milliliter (red). Rapla, Paide, Haapsalu, Pärnu, Jõgeva, Põlva have all moved to the same level.
Less concentration of the virus has been seen in Rakvere and Viljandi.
Editor: Helen Wright