James Griffiths writes:

Only a week ago, Hong Kong seemed like a model for how to contain the novel coronavirus, with a relatively small number of cases despite months of being on the front lines of the outbreak.

That was in large part thanks to action taken early on, while cases were spreading across mainland China, to implement measures that are now familiar throughout the world: virus mapping, social distancing, intensive hand-washing, and wearing masks and other protective clothing.

Hong Kong was proof that these measures worked, with the city of 7.5 million only reporting some 150 cases at the start of March, even as the number of infections spiked in other East Asian territories like South Korea and Japan, and spread rapidly across Europe and North America.

Now, however, Hong Kong is providing a very different object lesson — what happens when you let your guard down too soon. The number of confirmed cases has almost doubled in the past week, with many imported from overseas, as Hong Kong residents who had left — either to work or study abroad, or to seek safety when the city seemed destined for a major outbreak earlier this year — return, bringing the virus back with them.

On Monday, Hong Kong Chief Executive Carrie Lam announced that all non-residents would be barred from the territory as of Wednesday, the latest addition to a raft of new measures.

This is a pattern playing out across parts of Asia — mainland China, Singapore, Taiwan — that were among the first to tackle the outbreak. All are now introducing new restrictions as a sudden wave of renewed cases begins to crest. [Continue reading…]