Guardian said:...discovery of the decisive role in the spread of the coronavirus epidemic of asymptomatic people. When the study began, on 6 March, there were at least 90 infected in Vò. For days now, there have been no new cases. “We were able to contain the outbreak here, because we identified and eliminated the ‘submerged’ infections and isolated them...
One Italian town found the secret. Test everybody to find out who is infected, and quarantine just them. To do that you need to be able to build a lot of tests, reagents, and swabs though.
You don't have to quarantine everybody in the country, just those who are infected for a few weeks. Where are the tests?