But the large-scale quarantines in Wuhan have created confusion and frustration, and put some patients at even greater risk.

Confirmed coronavirus patients showing mild symptoms are being massed together, while those suspected of being infected are being isolated in converted hotels and schools.

The latest: China is using its telecommunications firms, all state-run, to track users who may have visited Hubei. Japan confirmed its first death from the virus, which is the third outside mainland China.

Changing numbers: China’s shift to using CT scans to look for pneumonia rather than relying only on a positive test for the virus appears to have caused a sudden rise in the number of reported deaths and infections. Experts say the scans could catch many more cases. For now, the World Health Organization is continuing to rely only on confirmed test numbers.