A Royal Children's hospital patient, staff member and two parents connected to the neonatal intensive care unit tested positive to COVID-19, it was confirmed on Monday.

As a result of contact tracing there are currently 17 RCH staff, seven patients and three parents identified as close contacts of the identified cases, all of whom are now in 14-day self-quarantine.

A spokeswoman from the hospital confirmed the baby's stable condition with AAP on Tuesday.

Health Minister Jenny Mikakos told reporters on Tuesday all but one result in the unit had come back negative.

"Yesterday we reported a baby there, two parents and a health care worker had tested positive," Ms Mikakos said.

"The latest advice that I have is that all the results have been received bar one result that is still pending of the babies at the NICU and they have all come through as negative."

All babies, staff and parents who have visited the ward since July 12 were to be tested.

The RCH told AAP a connection between the four cases has not yet been established.

The hospital alerted all of the neonatal ward and inpatient families as soon as the positive cases were confirmed.

The RCH has not allowed visitors on site since March, before hospital visitor directives were issued.

Any parent, guardian or staff member entering the hospital must undergo health screening and temperature checks before coming in.

Australian Associated Press