They literally bulldozed streets overnight and welded people into high rises. We all saw the videos until CCP stepped in.
Or we could threaten the virus:
BNO Newsroom
@BNODesk
North Korean leader Kim Jong Un: “In case the infectious disease spreading beyond control finds its way into our country, it will entail serious consequences.
And even at that it's only slowed it down. And since then it's becoming apparent from different reports that reinfection seems to happen to some people as well.
This is the new, happy version of those events. When a person gets sick and tests positive. They are given the choice to enter quarantine or stay home. If they stay home they cannot ever leave. The door is sealed. They are fed through window. If door seal broke, checked daily, they are forceably taken to quarantine. They can stay at home for an undetermined length of time. See. Everyone us happy according to Chinese. Although I have read it only takes one sick person in building. Then entire building sealed at entrance.