Victorian health authorities have issued notices of new virus exposure sites after a COVID-19 cluster at Melbourne’s Holiday Inn hotel grew to three.

A food and beverage worker and an already released returned traveller tested positive on Tuesday, leading to alerts for seven new exposure sites in the town of Sunbury, just north of Melbourne.

Five of the COVID-19 exposure sites are in Sunbury Square Shopping Centre. They include a Bakers Delight, massage clinic, deli shop and two restaurants.

Tuesday’s two new cases are linked to the Holiday Inn at Melbourne Airport, where an authorised officer who tested positive on Sunday had worked.

The emergence of the cluster has forced more Victorians into isolation and sparked another review of the state’s hotel quarantine system.

The returned traveller had tested negative several times during her stay, which ended on Sunday. She got tested again on Monday after learning of the outbreak.

The woman did not leave home other than to get tested and only one primary close contact has been identified so far.

The food and beverage worker worked on the same floor as the returned traveller and was identified as a close contact of the positive authorised officer.

There are now three virus cases linked to the Holiday Inn at Melbourne Airport.

Chief health officer Brett Sutton said the latest infections were likely linked to transmission on a floor with known COVID-positive guests.

That includes a family of three, one of whom has been transferred to intensive care.

The following exposure sites were added by Victoria’s Health Department on Tuesday:

• Cellarbrations, Sunbury
• Sunny Life Massage, Sunbury Square Shopping Centre, Sunbury
• PJ’s Pet Warehouse, Sunbury
• Bakers Delight, Sunbury Square Shopping Centre, Sunbury
• Aldente Deli, Sunbury Square Shopping Centre, Sunbury
• Sushi Sushi, Sunbury Square Shopping Centre, Sunbury
• Asian Star, Sunbury Square Shopping Centre, Sunbury
• See the latest list of Victorian exposure sites here

Tweet from @VicGovDH

Professor Sutton indicated the infected workers and former guest appeared to have picked up the virus from the family, despite having no close contact as he defended the state’s quarantine system.

“Cases can happen anywhere, at any time, and they can happen without a breach of protocol or any particular errors being made,” he said on Tuesday.

“We are talking about an incredibly infectious virus. We have known that airborne transmission is possible.”

He said health officials needed to continue to investigate every intervention possible to better protect hotel quarantine workers and guests.

“All I can say is bring on the vaccine,” Professor Sutton said.

Meanwhile, NSW Health has expanded its warning for people who were at the Holiday Inn following the emergence of the two new cases.

Anyone who worked or stayed on any floor of the hotel from January 27-February 9 is considered a close contact and must get tested and isolate for 14 days, the department said late on Tuesday.

Its previous advice applied only to people who had been on the third floor of the hotel.

-with AAP