An Australian high school has been forced to shut its doors for the immediate future after a 16-year-old student tested positive for the COVID-19.

According to New South Wales (NSW) State Premier Gladys Berejiklian on Friday, the decision to close Epping Boys High School in North Sydney was not taken lightly, the Xinhua news agency reported.

"Our first concern is for the health of the school's students, and it was decided that until we learned more about this specific case, the school should be closed as a precaution," she said.

"I'd encourage the community to remain calm at this time as the men and women in our health system continue their excellent work to minimise the impact of the COVID-19."

With investigations now underway to determine how the teenager contracted the virus, NSW State Health Minister Brad Hazzard said: "We expect over the weekend there will be a detailed examination of where the student has been since he contracted the virus and with whom he has been in contact."

Meanwhile, with the nation's total number of COVID-19 cases now reaching 60 overnight, authorities are still trying to locate around 80 doctors who attended a radiology conference in Sydney on Feb. 18, after it was revealed that two people at the meeting -- a 27-year-old woman from Liverpool Hospital and a 53-year-old man from Ryde Hospital -- were infected.

As a result, 61 staff and 56 patients at Ryde Hospital have been placed in self-isolation, while 23 staff and five patients at Liverpool Hospital have "been identified as potential close contacts of the female doctor and will be advised whether they require isolation".

"I want to reassure the public that we have several mitigation strategies in place to backfill any absent staff with other health workers to ensure continuity of service in our hospitals," NSW Chief Health Officer Kerry Chant said.