HONG KONG—After 23 days without a locally transmitted coronavirus case and with much of the city returning to normal life, health officials here are investigating how a 66-year-old woman and her granddaughter tested positive. The test results, announced Wednesday, illustrate the continuing challenges for authorities world-wide in eliminating the disease even in places that were successful with containment earlier on.

Source: Wall Street Journal May 13, 2020 11:51 UTC