COVID-19 elimination versus suppression: where does Tasmania stand?

A Tasmanian GP says now is the time the state government should be coming out with an elimination strategy, to avoid further outbreaks.

To date Prime Minister Scott Morrison has stood firm on Australia's COVID-19 suppression strategy, saying Australia cannot shut down to contain a potential second wave.

Launceston GP Dr Jerome Muir Wilson said while Tasmania's Public Health response had seen a temporary elimination of COVID-19 in the state, suppression would not be enough moving forward.

"The suppression strategy was right early on. But the more we've learnt about it, it's very hard to keep low levels going in the community without it flaring up," he said.

"As it stands now, it is going to be very hard for Victoria to eliminate it [COVID] now. Because they weren't aiming for elimination, when it got to 10 or 12 cases, it then quickly ramped up to hundreds.

"Moving forward, as we [Tasmania] start to talk about opening borders, I think as a state we should be aiming for an elimination approach. We have got there [elimination] already in Tasmania, but I think we got there accidentally and it won't last."

Elimination and suppression strategies employ the same control measures. In the case of COVID-19, this includes the identification and isolation of cases and border controls.

However, the main point of difference between approaches is the strictness, timing and duration with which the measures are applied.

Dr Muir Wilson said if Tasmania wanted to avoid another outbreak, an elimination approach was best.

"Suppression is basically having a bit there, then cases go up, and then you put in measures to bring it down again, but not to zero," he said.

"But if you are aiming for elimination in the first place you are going to clamp down very quickly on one or two cases. Whereas if you are aiming for suppression, you will look at one or two cases and think - 'oh that's OK'.

"But then it just takes one pub event and you have 40 cases or more overnight and that's what we have seen in Victoria."

Victoria recorded 217 new cases of coronavirus on Saturday, bringing the state's total to 5353, with 2608 of those still active.

Premier Peter Gutwein has already delayed an announcement on when Tasmania will reopen to mainland visitors, with an update now expected in early August.

Dr Scott Carver, a senior lecturer at the University of Tasmania specialising in the ecology and epidemiology of infectious diseases, said Tasmania had already proven that COVID-19 elimination was possible.

"One of the things that has been illustrated quite well by this Victorian outbreak is the challenges associated with suppression and a large city scale, because of the larger contact networks," he said.

"So in much the same way with the Burnie outbreak, they [Public Health] had to impose significant restrictions for the entirety of Burnie to suppress it and ultimately eradicate it.

"I expect if you had the same sort of thing [outbreak] happen in Hobart or Launceston, a similar approach might also be needed.

"But the real challenge with COVID is that you get transmission before you see symptoms.

"So you are going to have undetected transmission events that can very rapidly lead it to spreading out into other areas. That's possibly an argument for eradication."

Health Minister Sarah Courtney said the government was continuing to act on Public Health advice.

"As we have said, we are not just fighting a health crisis but an economic one, and we have lifted restrictions sensibly and responsibly to ensure the safety of Tasmanians while allowing our economy to reopen and recover," she said.

"The reality is elimination is not something we expect to see in Australia without a vaccine. That's why we have taken a glide path approach out of this to help manage risks as they arise.

"... the last thing we want in Tasmania is a second wave that will force businesses to close again, as there is no doubt that some will not be able to reopen a second time."