COVID-19 testing in Adelaide (Image: AAP/David Mariuz)

South Australia’s coronavirus cluster has grown to 20 cases today, with the state imposing new restrictions and calling in the defence force in an attempt to get the outbreak under control.

The latest COVID-19 spot fire has arrived just as Australia seemed on the verge of eliminating the virus altogether, after Victoria recorded its 18th consecutive day of no new cases. 

It also once again raises the question: what does our new normal look like?

Open by Christmas?

The SA cluster puts Scott Morrison’s plan to have all internal borders open by Christmas in jeopardy.

WA Premier Mark McGowan warned the plan was unwise, and he might have a point.

Every state and territory except NSW and the ACT has announced new border restriction for SA travellers, even as Morrison and NSW Premier Gladys Berejiklian argue that small numbers of cases can be managed while the economy, and the borders, remain open.

Lessons learned from other states

Like Victoria’s second wave, SA’s cluster stems from an apparent breach in hotel quarantine, quickly spreading through a large family, many of whom work in high-risk settings including prisons, aged care and health care.

University of NSW infectious diseases epidemiologist Abrar Chughtai told Crikey SA’s cluster could quickly snowball into a situation like Victoria’s.

“Almost 50% of infected people are asymptomatic … we should expect more cases in the community,” he said.

The SA government has acted quickly: international flights have been suspended, gyms have been closed, pubs and clubs limited to 100 seated patrons, and home gatherings to 10 people.

“We have evidence now that shows strict measures work in the absence of vaccines,” Chughtai said, adding the next step would be to implement postcode lockdowns.

Victoria waited until the state had more than 300 active infections to implement postcode lockdowns. By then, it was too little, too late.

Following Victoria’s failures in contact tracing, SA has accepted help from federal National Incident Centre contact tracing teams. SA will also start testing quarantine staff weekly. Following NSW’s lead, SA is also publishing high-risk locations.

“These small outbreaks are totally expected and will continue until we have an effective vaccine,” Chughtai said.

Quarantine needs to change

University of South Australia biostatistics and epidemiology Professor Adrian Esterman told Crikey fighting constant clusters didn’t have to be the new normal.

“Unless we change the quarantine system we’re going to get breaches,” he said. Esterman questioned why we were quarantining highly infectious people in the CBD.

“I can’t see why the federal government wouldn’t use places like Christmas Island or Woomera to quarantine people so infections can’t leak out into the general population,” he said.

Esterman also believes Australia should also be embracing rapid antigen testing at both state and national borders (the tests take just 15 minutes to provide a result, but are not as accurate as other methods).

“When community transmission is so low, this makes for a good second-check for everyone crossing a state border,” Esterman said.