Slight decline in infections; many infected do not consider themselves unwell

The recently ended stage in the coronavirus prevalence study, conducted by the University of Tartu, shows that although the number of infected adults has somewhat decreased since the holidays, the general infection level remains high. A cause for concern is the large proportion of asymptomatic infected people, as well as the behavioural patterns of potential close contacts.

In the course of the monitoring study stage from 21 January to 1 February 2,468 people were tested, 42 of whom tested positive. Nine of these had already overcome the disease, 33 were still contagious. Slightly more than half of the infected had no symptoms. Researchers estimate that 1.7% of the Estonian adult population, or about 17,700 people, are contagious. Therefore, on average, one in 59 grown-up residents is infected with the coronavirus. In comparison, during the survey stage conducted at the beginning of January, the estimated percentage of contagious people in the adult population was 2.3%, that is, one in 43 grown-ups.

According to head of the study Ruth Kalda, University of Tartu Professor of Family Medicine, it is now clear that the reason for the record infection numbers reported after the previous stage of study was, primarily, the parties and visits during holidays, and the close contacts it involved. “The results of the current stage show a decrease in both small-group gatherings and domestic travel. This may also explain the decline in the infection rates,” Kalda explained.

Behavioural study reveals risks

Kalda says that today it is primarily necessary to avoid close contacts in order to bring down infection rates. In the recently ended stage of the study, 52% of the people who tested positive were asymptomatic. Furthermore, 70% of those who tested positive and had symptoms considered themselves to be healthy. “These figures prove that there is a large number of people around us every day who unknowingly transmit the virus,” Kalda explained.

Compared to the previous study stage, the number of people exposed to potential infections has decreased. Thus, one in 17 people has had a possible close contact with an infected person (in mid-January, one in 12 people). One third of them did nothing to prevent infection and do not do so now, and continue, undisturbed, without making any changes in their daily routine. This is a very serious risk for the entire society; a risk that can create favourable conditions for the spread of infection. “Preventing the spread of the virus depends on every person’s efforts to take precautions. We are grateful to everyone who do that and we invite all others to make efforts, too, because this is what determines the further course of the epidemic in the upcoming months,” Kalda said.

The monitoring study is conducted by 17 researchers from five institutes of the University of Tartu. Synlab and Kantar Emor are involved as partners. More information can be found on the website of the coronavirus prevalence study.

Further information: Ruth Kalda, Head of Institute of Family Medicine and Public Health, Professor of Family Medicine, University of Tartu, +372 5698 5599,