[yfzhou]

China has been doing mandatory 14-day hotel quarantine for all foreign arrivals like this: https://twitter.com/nishantsharma87/status/12424610259510845...

However, the latest cluster in Heilongjiang involved an asymptomatic student returned from USA, completed 14 day quarantine, tested negative before and after, but still went on to infect her family and neighbors who infected more at the hospital. Total confirmed cases in this cluster is ~50 right now.

Most of the spread in this case happened because of negligence in the hospital thinking coronavirus is eradicated there so they didn’t take precautions. Coastal cities like Shanghai are taking good measures so there hasn’t been a problem despite it being where most international flights land and basically 100% back to work for over a month now. The biggest danger is people becoming tired of wearing masks and avoiding gatherings over time.

[greedo]

The simplest explanation would be that the student was infected after quarantine.

[alisonatwork]

I agree, but that would bust the narrative that there are no local carriers any more, only "imported cases".