It’s not just China that has got the virus under control. South Korea, Taiwan, Hong Kong too.
There are many differences between the Asian approach and the Western approach. It’s a combination of closing borders, testing, tracing, mask wearing and quarantining.
Of all these, I’d say the one that makes most difference is probably the way in which patients and their close contacts are immediately removed from the community.
Taking Hong Kong as an example, anyone who tests positive is immediately hospitalised in specific, negative pressure wards. They will remain in hospital until they have tested negative a number of times.
Contact tracing is done immediately and all close contacts are moved to quarantine facilities, where they are also monitored for a number of days.
For example, there was one local case in Hong Kong today. As a result, 16 close contacts were identified and moved to quarantine. A school was closed for two weeks and other venues where the woman had been were disinfected.
This heavy handed approach means that infections are not seeded in the community.
The requirement to quarantine is also strictly enforced. People coming in from very high risk countries (Bangladesh, Nepal) are sent to quarantine centres. People from high risk countries (the U.K., France) have to quarantine in a hotel room, even if they live in HK. All also have to undergo a test before flying, and another on arrival. People quarantining have to wear an electronic bracelet which tracks their movement. Police will come and enforce against rule breakers.