The doctors are on the lookout for any asymptomatic cases of cardiac arrhythmia or cardiomyopathy (enlarged heart) that could be of significance in young people.

Ministers believe that if passengers were tested only at airports on arrival then many asymptomatic cases would not be picked up.

The decree allows 1,000 spectators to attend football matches and reduces the period of quarantine for asymptomatic cases from 14 to ten days if they test negative.

That won't stop the spread of the disease but it should be sufficient to dramatically slow the rate of transmission, not least by identifying asymptomatic cases.