The state’s Chief Health Officer, Dr Kerry Chant, said authorities are acting in a “precautionary manner” after three returned travellers all tested positive to the South African strain of the virus.
The three cases include a family group of two and an individual traveller who arrived in Australia on April 3 on the same flight, and were quarantined next door to each other at the Mercure Hotel on George Street in the Sydney CBD.
The two family members were in connecting rooms on the hotel’s 10th floor, while the third person was in an adjacent room.
Dr Chant said the cases received negative test results for their day-two tests meaning they were not infectious while on the flight.
The family members tested positive on days seven and 10 of their stay, while the third person tested positive on day 12.
Dr Chant said there is a narrow possibility of a false negative test however that is unlikely.
She said health could not rule out a “common source of transmission” at the airport in Malaysia however transmission inside the quarantine hotel remains the primary concern.
A total of 40 people were staying on the same floor of the Mercure Hotel where the positive cases were undergoing quarantine during the period of concern.
NSW Health is contacting returned travellers who were on the same floor of the hotel from April 7-12.
Health authorities have contacted 36 of those people so far, but a number of them have travelled interstate.
“We are urgently escalating contact on the remaining four,” Dr Chant said.
They are asked to get tested and self-isolate until 14 days from the day they left quarantine at the Mercure.
Staff who worked on the floor are also being tested and self-isolating.
The three cases are all members of the one family who had been staying on the 12th floor of the Adina Apartments Hotel at Town Hall.
NSW has recorded no new cases of locally acquired COVID-19 in the last 24 hours.
Seven new cases were diagnosed in hotel quarantine.