A new case of COVID-19 — a 34-year-old nurse working at an isolated ward for treating novel coronavirus patients — was confirmed in Qingdao, Shandong province, on Thursday, the city's health authority said on Friday.

The patient, surnamed Jia, worked at the city's No 3 Hospital, where confirmed COVID-19 cases related to the city's pulmonary hospital, are being treated, according to an announcement of the city's municipal commission.

Before Oct 18, her nucleic acid tests came negative several times. She entered the isolated ward on Oct 18 and was working in a closed area and did not come in contact with outsiders.

All her contacts are those who were working at the same closed area. Their tests have been negative so far.

Experts said the nurse was accidently exposed and no loophole in the hospital's management was found. She was not infected at community and there is no risk of community-level spread.

The city's health authority has urged all medical institutions to enhance training for medical workers, improve their self-protected awareness and follow medical norms strictly.