April 22, 2020 16:53:34
Australia’s shutdown has been more relaxed than New Zealand’s, but now some experts are talking about eradication. (ABC News: Brendan Esposito)
To eliminate or suppress — that is the question.
As the number of coronavirus cases across Australia continues to drop dramatically, some experts, and the community at large, have started exploring that very question.
Yet, the answer is not simple.
Since declaring the pandemic last month, Prime Minister Scott Morrison has stood firm on a “containment and suppression” COVID-19 strategy — with the way out to the “other side” determined by data modelling to make sure the “effective reproduction number” stays below one.
A gradual lifting of social-distancing restrictions would follow broader testing and better contact tracing over the next three weeks, he said, giving medical staff time to prepare for any potential second or third-wave outbreaks.
He stressed Australia was “not in eradication mode”.
This differs from New Zealand’s hard shutdown — which was wound back slightly this week — and elimination policy.
But with the latest statistics showing Australia in a better position than many predicted — and almost on-par with New Zealand’s cases per head of population — some, like Victoria’s Chief Health Officer, have put elimination back on the agenda.
What are the experts saying?
University of Queensland virologist Kirsty Short told the ABC that Australia’s case numbers over the past two weeks suggested eradication of coronavirus was feasible.
According to the World Health Organisation, “eradication” is defined as four weeks without a single case — the equivalent of two incubation periods.
Dr Short said the problem with the elimination strategy, if it was implemented, meant it would block off our borders “indefinitely” as the virus continued to spread outside of Australia.
“Whether or not that is practical is a completely different question,” Dr Short said.
Another risk was somebody falling through the cracks of surveillance.
Instead, she said Australia’s existing “suppression” tactic would result in a low level of infections circulating in the community.
“But it would never be so high to overwhelm the health system and see high mortality rates we’ve seen overseas,” she said.
Dr Short said Australia could learn from countries like Japan — which has a largely voluntary “lockdown lite” strategy — and Singapore, where loosening restrictions had seen a rise in cases.
The risk for New Zealand
University of Auckland microbiology professor and adviser to the New Zealand government Siouxsie Wiles said she was conscious the elimination strategy meant a long-term closure of New Zealand’s borders.
But “being a microbiologist” and not in government, she did not have a timeframe on how long that would be in place for. New Zealand reported six new cases on Wednesday and has so far had 1,113 cases in total, of those 1,036 have recovered and 11 people have died.
“It is going to be all about how we manage people coming into the country,” Dr Wiles said.
“They [the New Zealand Government] do know what the risk is when we get uncontrolled movement of people if those people are infected.”
ANU infectious diseases specialist Sanjaya Senanayake said New Zealand was not “doing any better than us” in terms of cases per head of population.
Experts say Australia’s suppression tactic has largely worked. (ABC News: Brendan Esposito)
“That may be one of the reasons they’re looking to cut back on their measures,” Dr Senanayake said.
He said any elimination would only be short-lived, at least until a vaccine was found.
He believed the gradual lifting of restrictions meant health and government agencies would need to be on alert for new outbreaks throughout the year, and did not think Australians would be “shaking hands any time this year”.
“Lifting restrictions does not mean you lift surveillance,” he said. “We should intensify that and testing because we want to jump on cases immediately, and contact trace to quarantine new cases.
“Businesses reopening will have to rethink how they operate.
“Restaurants that have 50 people in there usually, may only be able to have 10, and we may have to get used to seeing waiters in gloves and masks.”
“Factories may need to put plexiglass between workers, these sorts of things will have to happen.”
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Elimination creates other problems
Speaking on ABC News Breakfast on Wednesday, Deputy Chief Medical Officer Nick Coatsworth said the issue with pushing towards eradication or elimination was creating a “non-immune population”.
He said Australians would have to live under social restrictions for far too long to effectively achieve elimination.
“If in the process of suppressing, we get to the point of eradication, then that would be a magnificent outcome,” he said.
“But we must continue to build capacity and we must continue to contain the virus, and remember that we’re not immune from it.
“So, [the] strategy that we’re using is to ‘suppress’ COVID-19 until there’s a vaccine.”
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Speaking of the vaccine…
Kirby Institute epidemiologist Raina MacIntyre said Australia should be aiming for elimination like New Zealand — however, elimination did not mean getting rid of the disease altogether, but rather ensuring breakouts did not “take off”.
She said the rate of reproduction from COVID-19 “while still volatile” appeared to be similar to smallpox, which was much lower than other diseases like measles.
“For smallpox, which was the only human disease to be eradicated, [you] only need about 60 per cent of people to be immune to eradicate it,” she said.
“Measles is very difficult because it is so infectious you need a very high proportion of the population to become immune before you can eradicate it.
“COVID-19 is about the same value as smallpox.
“That’s good news because even if we don’t have a great vaccine amongst the first vaccines that will arrive; even if it only has an efficacy of 70 per cent, that still should be good enough to control COVID-19.”
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April 22, 2020 15:02:43