South Australia has hopefully caught its second wave of coronavirus just in time.
But detecting that strain all came down to the persistence of one young doctor at Adelaide's Lyell McEwin Hospital, who insisted on testing an elderly woman for coronavirus after she presented to emergency on Friday night with a cough.
The woman, aged in her 80s, is the mother of a cleaner at Peppers medi-hotel, who is believed to have caught coronavirus from a surface at the hotel.
South Australia had gone more than seven months with no community transmission when the doctor realised it might be coronavirus.
Chief medical officer Professor Paul Kelly praised the doctor yesterday.
"There was a young doctor in the hospital in northern Adelaide who was absolutely essential in picking up that first case," Kelly said.
"The family member that went to that hospital and went to the Emergency Department with something else completely different, no respiratory symptoms, one of the doctors heard that person coughing and did the test and that is how we know that there's something going on in South Australia very early.
"And they're getting on top of very early, I am confident they will get on top of it."
Dr Chris Moy, the president of the South Australian branch of the AMA, said it basically came down to luck that the state had found the case.
"Because of the conscientiousness of a particular doctor who insisted that a patient with minimal symptoms have a test," Moy said.
"Really to some degree that may make the difference and may mean that we've caught it early and it hasn't got to the Victorian level where it was going on for weeks."
Moy said "by the grace of God" the doctor "stayed committed to that vigilance in a community that hasn't seen any cases for months and then that has actually closed this down".
The doctor's insistence meant South Australia had hopefully caught it quickly and would be able to "control it like a spot fire instead of it turning into a bushfire as it did in Victoria", Moy said.
Chief public health officer Professor Nicola Spurrier explained her "rationale" behind the 14 day lockdown yesterday, admitting the state's strain of coronavirus had an incubation period of around three days, causing it to spread rapidly.
Epidemiologist and former employee of the World Health Organisation, Professor Adrian Esterman, explained why South Australia's virus strain was particularly bad.
"It's dangerous because it's highly infectious," Esterman told Today.
"This virus is what we call an RNA virus. All viruses are made of genetic material and they can be either DNA or RNA. Some viruses are RNA like HIV and influenza and they tend to mutate much more than DNA viruses.
"So the coronavirus is making small changes and every once in a while they make a big change which is why we need to make a big change."
Esterman said "quite possibly an existing strain that has hit funny circumstances that made it change its incubation period".
The incubation period for the South Australian strain has been found to be less than three days – sometimes 24 hours – with the virus usually incubating for around 14 days.
Esterman said the short incubation period meant South Australia could hopefully rid itself of the virus with its short six-day lockdown.
"The thinking is that this has a very short incubation period of, on average 24 hours so that means the maximum incubation period is three
days," he said.
"So if we take two cycles we have a chain of someone being infected to infecting someone else and the maximum for that is three days and, therefore, two incubation periods is six days… with the usual situation it's usually an incubation period of 14 days and the next cycle is 28 days."