Health officials took no chances on Wednesday, sealing off the capital of the industrial Hebei province and ordering a mass testing drive.
Travel restrictions were put in place in the remainder of the region, which encircles China's capital Beijing and is home to some 76 million people.
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By Saturday, Mayor Ma Yujun told a news conference that it had taken just three days to complete the first round of mass testing in Shijiazhuang, with 354 people found positive for the virus. A second round of testing is due to begin soon, he added.
Yan Xixin, a critical care director at the Second Hospital of Hebei Medical University, told the same news conference, "the risk of having more infections is still there."
This hard-and-fast approach is being echoed elsewhere in the Asia-Pacific region to fend off coronavirus flare-ups — including in Japan, Thailand and Australia — making measures to curb the virus spread in Europe and the United States appear almost sluggish.
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