In Australia, where Victoria state has been reporting record deaths, some 3,000 checks last month on people who should have been isolating at home found 800 were out and about. In Japan, where the virus has roared back, people are staying home but aren’t in isolation: 40% of elderly patients are getting sick from family members in the same apartments.

The failure to effectively manage contagious people with mild or no symptoms is a driving factor behind some of the world’s worst resurgences. But lessons from Italy, South Korea and others that have successfully contained large-scale outbreaks show that there’s a tried-and-tested approach to cutting off transmission: move them out of their homes into centralized facilities while they get over their infections, which usually doesn’t require longer than a few weeks.

“A laissez-faire approach naively trusting everyone to be responsible has been shown to be ineffective, as there will always be a proportion who will breach the terms of the isolation,” said Jeremy Lim, adjunct professor at the National University of Singapore’s Saw Swee Hock School of Public Health.