The Czech Republic will test 27,000 people for coronavirus antibodies to gain information on how many came into contact with the infection, officials have said.
The study, wider than others done in European countries and the United States in recent weeks, will start on Wednesday and involve all age groups.
Four regions were picked, from areas that were little affected by the virus to ones highly affected, Institute of Health Information and Statistics Director Ladislav Dusek said, according to Reuters.
Results, expected in early May, should give the government a clearer view of how many asymptomatic cases there may have been and help decision-making on further steps.