Queensland's Covid-19 cluster has grown by 10 cases overnight - including eight community cases - as millions of Brisbane residents wake to their first day of a three-day snap lockdown.

Brisbane is now dealing with two separate Covid-19 clusters after a doctor and a nurse at the same Brisbane hospital contracted the UK strain of the virus from different patients.

Of today's eight new community cases, five are linked to a hens party in Byron Bay, NSW, whose guests were infected by the Brisbane nurse.

Queensland Premier Annastacia Palaszczuk said the state is now dealing with two distinct clusters.

First cluster: 8 people, with two under investigation
• In early March three cases were linked to a Princess Alexandra Hospital doctor that contracted coronavirus from a patient. This is considered the first cluster.
• In the past few days five more cases have been linked to that first cluster.
• There are also two more cases under investigation that authorities believe may be also linked to the doctor.

Second cluster: 8 people
• The second cluster is linked to a Princess Alexandra Hospital nurse who is also believed to have contracted the virus from a different patient.
• That nurse then attended a hens night in Byron Bay, NSW, and there are now seven confirmed cases in that cluster. Including the patient, who is a returned traveller, the second cluster stands at eight people.
• There is an additional infection that could be linked to either the first or second cluster.

'Hens entertainer' linked to second cluster

A Queensland tradie who travelled to Byron Bay to attend the hens party as an entertainer then returned to the Gold Coast and visited an aged-care facility while infected. The man is now part of the second cluster.

The hens entertainer evidently became infected at the party before returning to the Gold Coast where he attended the TriCare Mermaid Beach Aged Care Residence as a contractor working on refurbishments.

The revelation has plunged the nursing home into high alert as efforts to track down possible cluster links continue.

There are now 78 active cases in Queensland. No new cases were detected in NSW overnight.

A mask mandate and other restrictions have been imposed for the entire state of Queensland, while more than two million people living in Brisbane, Moreton Bay, Redlands, Logan and Ipswich council areas can only leave their homes to shop for essentials, attend medical appointments, exercise, and to work or study if they cannot do so at home.

"The good news is that these cases are linked and we now believe that there are two distinct clusters," Palaszczuk said.

"So, we have a cluster linked, of course, to that Princess Alexandra doctor. And we have a second cluster linked to the Princess Alexandra nurse."

Palaszczuk said today's figures show sending Brisbane into lockdown was "absolutely the right call".

The next 48 hours are critical in determining whether the state's outbreak can be brought under control by the time the snap-lockdown is set to end, Palaszczuk said.

"What we don't want to see is unlinked community transmission out there," she said. "So you know, like I said – the next two days is critical for our contact tracers to get on top of this."

Chief health officer Dr Jeannette Young said she will introduce a new mandate from tomorrow that will see only hospital and health service workers who have had their first vaccine dose allowed to work with confirmed coronavirus cases.

It follows revelations that the nurse who contracted Covid-19 had not received her vaccination despite working in a Covid ward. Queensland authorities have deflected blame on to the Federal government, pointing to supply issues which have drastically impacted the speed of the national vaccine rollout.