A breach of hotel quarantine poses the greatest risk for a new COVID-19 outbreak in the ACT, Grattan Institute researchers say.
Modelling in the think tank's new report shows workplaces returning to full capacity could lead to a significant increase in active cases at a national level.
Grattan Institute health program director Dr Stephen Duckett said the ACT was a safer jurisdiction because of its low level of locally acquired cases and the fact it currently has no active cases, but it was important not to become complacent.
"I think [the ACT is] in the elimination phase, but I wouldn't throw caution to the wind," he said.
"There's always going to be potential for an outbreak. With porous borders, someone is bound to drive from Sydney to Canberra sometime.
"While Australia is not in the elimination phase, you'll have to be cautious about running a huge football game, for example, because that would overwhelm your testing and tracing capacity."
Dr Duckett said repatriation flights and the upcoming international student pilot might increase the number of recorded cases but that would not be a problem if the quarantine process was strong.
He said there was a risk the virus could get out of the hotel via an employee, or that someone could be carrying the virus for an unusually long incubation period, beyond the 14 days of quarantine.
The modelling showed returning to work with weak adherence to social distancing could pose a big risk in increasing the number of cases while poor social distancing and lifting restrictions on patron numbers in shops would present a severe risk.
Reopening workplaces could pose big risks:
Dr Duckett said larger workplaces were at greater risk because of a greater potential for interactions between people. The risk of transmission was higher in shared spaces, such as lunchrooms or meeting rooms.
He said shops posed a higher risk because it was more difficult to conduct contact tracing.
"With workplaces you know who is there whereas if you're crowded into a shop, it's almost impossible to know who is there especially when the COVIDSafe app doesn't work as well as we might have hoped."
Poor social distancing in open shops presents a severe risk:
The modelling showed opening schools increased the risk of outbreaks slightly.
Opening schools only increases risk of outbreaks slightly:
The researchers argue for another phase to be added after the stand-down phase of pandemic planning in order to address secondary problems.
"We're not only thinking about the response to the infection, we're also thinking about the response to the response. That is we're thinking about the mental health issues, the domestic violence issues, the alcohol and drug issues that are associated with the pandemic," Dr Duckett said.