Australia shortens COVID-19 isolation period

Australia’s national cabinet – a meeting of the nation’s first ministers – has decided to cut the COVID-19 isolation period for infected people to five days after testing positive. Australians will only need to isolate for five days after their positive test, unless they continue to show symptoms on the fifth day.

Isolation was previously set at one week following a positive test.

Those working in high-risk settings such as aged, disability and at-home care will still need to isolate for seven days.

National cabinet also removed the requirement to wear masks on domestic flights.

The changes come into effect nationally from Friday 9 September. Prime minister Anthony Albanese described the decision as being a “proportionate response at this point in the pandemic,” citing the importance of individuals” looking after their own health.”

In response, the Australian Medical Association queried the advice that informed the decision and is calling for its release.

“Governments must base their decision-making on the health and medical advice and we need to see that advice and whether it supports today’s decision,” said AMA president Professor Steve Robson. 

“If it doesn’t, the politicians need to explain themselves.”

A negative RAT should be a ticket out of isolation

Professor Bruce Thompson heads the University of Melbourne’s school of health sciences. He says the decision to shorten the isolation window to five days doesn’t make much sense, given infectiousness can extend beyond that time.

A more sensible move, he says, would be to require a negative rapid antigen test (RAT) to exit isolation.

“I think it’s a solution trying to find some science to support it,” he told Cosmos.

“What I believe they should do is [require] a RAT. Then if you actually are negative, then it’s unlikely you’ve actually got transmissible virus. But they haven’t done that.”

The decision to bring the ‘exit window’ within five days aligns Australia to current rules in other nations, notably the United States.

Recent research among a small study group found it took up to 15 days for culturable virus to be fully destroyed by the body. But after five days, half of the study group still had virus present.

Dr Kristy Short, a virologist from the University of Queensland, highlighted the confidence a negative RAT result can provide. Even though they’re not fool proof, RATs are better able to indicate infectiousness than a polymerase chain reaction (PCR) test.

“I personally would want to be RAT negative before I was out and about,” Short told Cosmos in July.

“We equate these rapid antigen tests as more indicative of when you’re infectious than a PCR test, because the viral protein is indicative of replicating virus.”

Reduction in isolation periods could come back to bite in spring

Thompson points out that potentially having still-infectious people cleared to re-enter public life after five days will risk disease spread, which increases the risk of new variants emerging through mutations, and health authorities are projecting another COVID-19 infection wave in Australia at the end of spring.

Experts like Thompson are wary of decisions that lower transmission barriers like isolation periods. Even in a highly vaccinated population, transmission can still spread quickly.

With only 7 in 10 people having received a third booster, and fewer than 4 in 10 having received a winter dose, the potential exposure to re-infection is greater, even as case numbers dip from their recent July peak.

And while people are now believed to be capable of catching COVID-19 within 28 days of a previous infection thanks to new subvariants, the timeframe to receive a booster jab is set at three months after recovery from the illness.

Inconsistencies like these are themselves symptoms of nations learning while working on stopping a fast-evolving pathogen, Thompson says.

“We’re still in that learning phase ultimately. You’re always going to get inconsistencies,” Thompson says.

“The fact that only a few years ago, we had a brand new virus – an absolute doozy, this one – and we’ve actually vaccinated the global population in a couple of years is extraordinary, it’s never been done before.”