BEIJING — A Chinese health official said the country must spare no effort to stem the spread of the novel coronavirus, as challenges remain for the medical treatment of COVID-19 patients and epidemiological investigations.

Two provincial-level regions, Beijing and Hebei province, had reported new local COVID-19 cases for at least five consecutive days by June 18, Hu Qiangqiang, an official with the National Health Commission, said on June 19 at a press conference.

The number of severe COVID-19 patients had increased for five straight days as of June 18, and the count of close contacts under medical observation kept growing, Hu said.