There is one new case of Covid-19 today in managed isolation. The new case is a woman in her 30s who travelled from London. She tested positive on her third day in a quarantine facility.
It could easily be "game over" for NSW if the coronavirus spreads to the wrong people as the state grapples to get infections under control.
Experts in NSW are anxiously watching new case numbers and there are fears the state could end up in a similar position to Victoria, which has entered another six-week lockdown.
Yesterday, there were 13 new coronavirus cases in NSW, with the state recording several days of double-digit growth in the past two weeks.
While the numbers are small now, Melbourne University epidemiologist Professor Tony Blakely said this could change quickly, as was seen in Victoria where case numbers jumped from under 20 on June 24, to 73 a week later. The state is now recording more than 200 cases a day.
"Covid behaves in chance ways," he said. "If the next person who got it in NSW was a superspreader who came in contact with another superspreader, it would be game over."
Superspreaders are people who are more likely to spread the virus to others because of a combination of factors including the pathogen, the patient's biology and their environment or behaviour.
A drive-through Covid-19 test clinic in Fairfield. Photo / News Corp
For example, a Melbourne man who came to Sydney for work has been identified as the "patient zero" of the Crossroads Hotel cluster that has seen 50 people infected.
While some might find the numbers in NSW nerve-wracking, Blakely believes they are getting better.
"They have stabilised a bit," he said. "It appears that NSW might be containing this through aggressive contact tracing."
Blakely said NSW appeared to be identifying where most of the cases were coming from.
"That is essentially the bedrock of an aggressive suppression strategy, to contact trace and test like crazy, in the hope of trapping the virus and to stop it spreading further," he said.
"That strategy clearly failed in Victoria."
Blakely believes authorities will have a better idea of how successful they have been in the next week.
This undated electron microscope image made available by the US National Institutes of Health in February 2020 shows the novel coronavirus SARS-CoV-2. Photo / File
When asked why contact tracing didn't work in Victoria, Blakely said it may have been a combination of bad luck and poor training.
"Victoria had a perfect storm of quarantine leakage, security guards taking it home to their families, and English may not have been their first language. Then you had big families mixing with big families," he said.
"If there had been perfect behaviour, and they weren't mixing with other groups, it may have been prevented."
The virus was able to spread widely even though Victoria had tougher restrictions at the time than NSW has had. An inquiry is now looking at whether every case in Victoria could be linked to the breaches of hotel quarantine.
Blakely said social distancing may not have been followed in the state but he didn't want to blame people and hoped that masks might make a difference in controlling future spread.
"If NSW has got that message and is not doing big family gatherings, combined with contact tracing, this may be enough to get in under control," he said.
"It's like a seesaw, you've got to stack up your side with as many things as possible to tip it in your favour."
Blakely said people should be encouraged to wear face masks in the areas where there were outbreaks in Sydney, and to keep their distance from others.
"You should only be leaving your house to go to work if you need to, you should be hand washing, all these things help."
If NSW did adopt an elimination strategy, Blakely said it may only require a stage 3 lockdown in the areas where the virus was circulating to get cases under control.
"You might only need four weeks, although a lockdown in postcodes didn't work in Victoria," he said.
Blakely said prior to Victoria's outbreak, NSW only had three cases of coronavirus, which had been locally acquired and they couldn't find the source.
"So they were getting extremely close to elimination," he said. "If they can get on top of this outbreak they may be able to achieve elimination by accident, as other states have done, so there's a lot in the balance in NSW."
"There's a lot left to chance with Covid but nevertheless NSW is perhaps getting on top of contact tracing and I hope they do."
