South Australia has reported one new case of COVID-19 linked to a cluster that briefly raised fears of a second wave of infections and sparked a short-lived statewide lockdown.
Chief Public Health Officer Nicola Spurrier said the latest case involved a member of the extended family group originally linked to the Parafield cluster.
The case was finally confirmed after an incubation of about eight days and came after the woman had twice tested negative.
It takes the total cases linked to the cluster to 27, with just one of those in hospital.
SA now has 38 active cases, 11 of them returned travellers.
All those with active infections remain in quarantine along with more than 4000 close contacts.
Professor Spurrier said the cluster was still a risk to the wider community and urged anyone with symptoms to get tested, and the wider community to wear masks whenever possible.
"If we have had more community transmission we will be starting to see it this week," she said.
But Prof Spurrier said she remains optimistic as contact tracers continue their "mopping up" of people who might have been exposed to the virus.
"I am quietly confident that we have got on top of this," she said.
"I'm a very positive person and I'm very confident about the decisions that we made last week."
Prof Spurrier said while it was normal to wait for 28 days, or two incubation cycles, before declaring an outbreak "all over red rover", the Parafield cluster had been identified very early and officials were quickly aware of the chains of transmission.
Premier Steven Marshall said the state was not "out of the woods yet" but he felt more optimistic that SA had avoided a major second spike in coronavirus infections.
"We stared down a catastrophic situation by acting swiftly and decisively on the expert health advice that we had received," he said.
The easing of concerns also left SA on track to open its borders to Victorians from December and positive about the chances of soon returning to a lower level of local restrictions.
Police Commissioner Grant Stevens said he was hopeful Christmas "will be celebrated as we would hope to celebrate it".
"I've given a pretty clear indication that we're aiming at the first of December to go back to a level where most community activities and family gatherings could occur," he said.
Police have also updated the investigation into the events that sparked SA's three-day lockdown, particularly the information provided by a worker at an Adelaide pizza store who is among those to test positive.
Assistant Commissioner Peter Harvey said police had looked through 400 hours of CCTV footage and had seized various electronic devices, including a phone and a computer.
He said investigators had identified two more people they wanted to speak with who were currently seeking legal advice.
Mr Harvey said his investigation would deal in facts, "not rumour and innuendo".
"We're really stepping back here. There's a lot of emotion and a lot of desire for something to happen," he said.
"But it will be done carefully, it will be done clinically and we'll put our case forward.
"There may not be a case, just the same there may well be, that's the point of the investigation."
Australian Associated Press