Chief public health officer Prof Nicola Spurrier told reporters this afternoon that only vaccinated people attended the Saturday event, understood to be a Henley High School 40th anniversary class reunion at Theatre Bugs, Norwood.

Former Premier Jay Weatherill attended the reunion and has tested positive.

According to SA Health the cases include eight men between the ages of thirty and sixty years old and ten women in their fifties.

The new cases bring the total to 31 since the borders reopened on November 23. Of those cases, 27 remain active.

Authorities suspect an interstate traveller at the event may have sparked the outbreak, but are yet to identify them. The other two cases are related to interstate travellers unconnected to the reunion.

Spurrier said that as at 9am on Thursday, 210 close contacts are in quarantine, but “that number is likely to increase.”

Questioned over why high profile close contacts such as Opposition Leader Peter Malinauskas had yet to be alerted by SA Health, Spurrier said contact tracers were facing a high workload.

“There are quite a number of people who have been in close contact, which involves a lot of work for our team in interviewing all those cases,” she said. “

“Many people when they receive the SMS being alerted they have COVID will let people know they need to quarantine, so there may be some lag between you finding out because a friend told you and us telling you – we will try to speed that process up.”

Premier Steven Marshall told reporters he had always said reopening the borders would lead to cases and the outbreak so far was in line with the modelling, which indicated roughly 20 cases a day for 30 days.

“We’ve got this, we’ve worked very hard to make sure South Australia is COVID ready before opening the borders,” he said.

Marshall, who got a COVID booster shot on Wednesday, said over 90 per cent of eligible South Australians have now had their first dose of the vaccine, and urged those still to do so to “help their family, friends and entire state”.

Marshall also expressed concern about the measures others states are putting in place to safeguard against the new Omicron variant.

“We are concerned that some jurisdictions in Australia don’t have the 14-day isolation requirement (for overseas arrivals) that we have in South Australia,” he said.

Marshall said new arrivals from NSW will from this afternoon be required to get tested on arrival.

South Australia will undertake full genomic sequencing of tests to monitor for any sign of the Omicron variant.

SA Police Commissioner Grant Stevens said there were no plans to close the borders at this stage, but noted that the state had prepared for the Delta variant and the arrival of Omicron to Australia was a concern.

“From a Omicron perspective, there are areas of concern and we’re watching,” he said.

“We are prepared for the Delta variant. I am hoping Omicron doesn’t affect our plans but we’re watching closely.”

Stevens said arrivals to the state at airports and via road would have their credentials checked.

Spurrier said SA Health were being more selective with the exposure sites listed, noting that two hospital sites had not been mentioned publicly.

“We haven’t been putting particular sites up, because as we get more disease in our state, we will only be putting up exposure sites on the web if we need the public to respond,” she said.

“In the case of the hospitals it was contained, all those people know they need to quarantine, so there’s no need to do an announcement.”

She urged the public to come forward for testing, noting that 8687 COVID tests were carried out on Wednesday.

SA Health on Thursday afternoon listed additional exposure sites, including a casual contact location at Stir Restaurant in Largs North on Monday the 29th of November from 10:45am to 11:15am.

Anyone at the site during those times must get tested immediately and quarantine until they receive a negative result.

Low risk casual contact locations were identified at Mount Barker General Hospital on Monday the 29th of November from 11:30am to 6:30pm, and BIG4 West Beach Parks at West Beach on Sunday the 28th of November from 1:00pm to 5:00pm.

SA Health yesterday listed exposure sites at Norwood, Glenelg, Unley and the city connected to the locally acquired cases.

The list does not include Ocean View College, which was closed today after a member of the school community tested COVID-positive.

Multiple sites known to have been frequented by positive cases — such as Parlamento restaurant where Weatherill had a coffee with Malinaskus at an outside table on Sunday — have not been included.

Marshall confirmed that Parliament would resume this afternoon, after being temporarily suspended as contact tracers worked to identify political figures who had come into contact with Weatherill.

SA Governor Frances Adamson is meanwhile in isolation as a close contact of Weatherill, after the two met at an event on Sunday, the evening after the school reunion.

Adamson has tested negative but will remain in isolation according to SA Health advice.

A Government House spokesperson revealed to InDaily that in addition to Adamson, another staff member has also been sent into isolation.

“I can confirm one Government House staff member is also in isolation on advice from SA Health,” the spokesperson said.

Weatherill had also done the media rounds after the Norwood event, including an in-studio appearance with FIVEaa hosts David Penberthy and Will Goodings. As a result, FIVEaa staff are in isolation, including breakfast presenters David Penberthy and Will Goodings who broadcast from their homes this morning.

The area in the vicinity of the Theatre Bugs event enjoys a strong vaccination rate, with the Norwood Payneham St Peters council area at 85 per cent fully vaccinated, 91.5 per cent first dose.

Weatherill told InDaily he was now in 14 days quarantine before a further two weeks when he returns to WA.

He said he was feeling “a bit ordinary” but was “just apologetic for all the inconvenience I’ve caused”.

-More to come