HELSINKI (Reuters) – Finland will start tracking the spread of the new coronavirus in its population with randomised antibody tests, its public health authority said on Tuesday.

The main hospitals will mail invitation letters to randomly chosen citizens of all ages to be tested for the antibodies which patients suffering from COVID-19 develop, including those who have contracted the illness without showing any symptoms.

The first tests will be in the region around the capital, Helsinki, and the results will be used to help the government decide what measures are needed to curb the spread of COVID-19, the respiratory disease caused by the new coronavirus.

“The main aim of the research which will begin now is to get up-to-date information on how large a proportion of the population has formed antibodies that indicate an earlier encounter with the coronavirus,” the Finnish Institute for Health and Welfare said in a statement.

“By assessing the occurrence of antibodies in the population, we can track to what extent the epidemic has spread among different age groups and in different areas.”

Finland has confirmed 2,176 confirmed coronavirus cases. Twenty-seven people in the European Union member state have died after contracting the virus.

(Reporting by Anne Kauranen, Editing by Timothy Heritage)