A third passenger from the Diamond Princess cruise ship tested positive for COVID-19, the state's chief health officer Brett Sutton confirmed on Tuesday.

The trio were repatriated to Victoria and are recovering in isolation.

This new confirmed case has brought the state's total number of people infected with the deadly virus to seven.

Four people who previously tested positive for the virus in Victoria have recovered, the state's health department told AAP.

The confirmation of several positive cases among the group of 164 evacuees from the Diamond Princess brought Australia's confirmed coronavirus cases to more than 20.

Globally, nearly 78,000 people have been infected in 29 countries.

People who have been in mainland China in the past fortnight should self-isolate for 14 days after leaving the Asian nation, authorities advise.

Meanwhile, a Melbourne hospital confirmed it didn't have any positive cases of COVID-19, but had put six members of its staff in isolation.

The Box Hill Hospital said six staff were undertaking self-isolation for people determined to be in close contact with the virus.

The Australian Nursing and Midwifery Federation said that nurses put in isolation can take a special leave and payment.

Australian Associated Press