New South Wales has recorded 172 community cases of Covid-19, its highest daily case total since the start of Sydney's current outbreak.
Of the new cases, 85 are linked to a known case or cluster and the source of infection for 87 cases is under investigation. Sixty cases were infectious while in the community.
NSW Premier Gladys Berejiklian made the grim announcement during this morning's Covid press conference.
She again urged residents to follow the state's lockdown rules and get vaccinated.
"My message to everybody is please come forward and get the vaccine," Berejiklian said. "Not only are you protecting yourself but you're protecting those closest to you."
Two Covid-related deaths, which were announced yesterday, have now taken total deaths in NSW during the current outbreak to 10.
Berejiklian said the two deaths were people who contracted the virus as household contacts and were unvaccinated.
There are currently 169 Covid-19 cases admitted to hospital, with 46 people in intensive care, 19 of whom require ventilation.
Berejiklian revealed a decision on a potential tightening of restrictions could be made as soon as tomorrow as Sydney's west emerges as the epicentre of the city's outbreak.
"I think what's important to note is that it's been a good time for the health experts to give us good data on how the virus is transmitting and in which way," she said.
"And consistently we've seen critical workplaces and also households be the main generators of the virus transmitting and they're the issues we need to focus in on."
Berejiklian said those factors would be taken into consideration when the government decided on "what life beyond July 31 looks like", saying she hoped to make such an announcement "as early as tomorrow, to give people plenty of notice".
Fury as five test positive
Five people from one household on the NSW Central Coast tested positive to coronavirus on Monday, igniting fears of potential further spread.
The positive cases, from Budgewoi, north of Sydney, resulted in 25 new exposure sites in the area.
Authorities are also worried about two close contacts who have so far tested negative, but who were living in the same household.
Meanwhile, attention is turning to the actions of one of those contacts, who visited 25 shops in five days after being ordered to isolate.
Lake Macquarie MP Greg Piper hit out at the act via social media, labelling it "disappointing".
"I simply cannot describe that situation, but let's settle on mind blowing and disappointing," he wrote.
What Sydney can learn from Melbourne's 2020 outbreak
If Sydney's Covid-19 outbreak mirrors Melbourne's experience last year, New South Wales can expect a peak in new daily cases this week.
But if the numbers don't start dropping over the coming days, then all bets are off for the trajectory of the outbreak and when the Greater Sydney lockdown will end.
In mid-June 2020, Melbourne went from very few cases to a peak of 687 on August 5 – around six or so weeks later.
The Victorian government introduced its highest level of restrictions on August 2, just a few days before that peak was reached.
The rolling average continued to hover around a high of 450 cases daily until 10 days or so after those new restrictions were put in place before steadily dropping – albeit with some spikes here and there.
It then took around another six weeks for Melbourne's cases to fall to relatively negligible levels, although it was late October before there were no cases at all.
The NSW government introduced its toughest restrictions yet on July 18. If they were to have the same effect as Victoria, then NSW would already have passed the single day peak and the rolling average of 135 cases could be on the cusp of dropping later this week.
"In some ways there are lots of similarities between the Melbourne outbreak and the current Sydney outbreak," said leading epidemiologist Professor Peter Collignon.
"In Melbourne, there was lots of community transmission for a while and then it was essentially in workplaces and households which sounds familiar. I'd hope there would be a similar trajectory in Sydney."
However, Collignon sounded a note of caution, saying while the "curve" of new infections was relatively flat, it was yet to head down as should be expected seven days after restrictions were introduced.
"I would have hoped we would have started to see some effect already. It's a different curve to Melbourne," he said.
Part of the challenge is the Delta variant, which is twice as infectious as previous strains of the virus and is stretching the capacity of contact tracers.
And of course there is ongoing debate about the finer points of the Sydney restrictions.
Unlike Melbourne last year, there is no curfew, a limit of 10km rather than 5km and mask wearing doesn't needed to happen outdoors unless it's crowded. Although within the hot spots areas there are some extra restrictions on top of that.
Collignon said the virus was circulating in homes and workplaces, environments far harder to manage, and that's where Sydney could be coming unstuck.
"To a degree, it feels like some in the community are not following even the lighter lockdown rules. That's the impression," he said. "We've had examples given of people having parties and families visiting other families."
On the weekend, NSW Health said one recent family gathering of 50 people, grieving the loss of a loved one, had led to 28 positive cases so far.
Speaking to reporters on Monday, NSW Premier Gladys Berejiklian referenced the gathering as she implored families and friends not to meet up.
"Do not mingle, do not have any exposure outside of your household with other households," she said. "We are still seeing that as a challenge. Especially as we have seen at a time of bereavement but we can't allow exceptions at this point."
Collignon said the state's inability to stamp out the virus was leading to a series of mini-outbreaks across Sydney that were keeping case numbers constantly high.
"It's not rising exponentially but the bad news is it's not coming down quickly enough," he said.
"Once it comes down in one area, it goes up in another. So in the eastern suburbs [where the current outbreak first took off] it's completely gone down.
"It also looks like Fairfield is going down, but in neighbouring Canterbury-Bankstown numbers are going up."
University of South Australia epidemiologist Professor Adrian Esterman said the five-day average of cases was still rising even though the outbreak should have "reached its peak and started coming down".
"Clearly, the lockdown either is not hard enough, or there are too many Sydneysiders not complying with lockdown,"
Nonetheless, Collignon said he there was one huge advantage that Sydney had this year that Melbourne didn't in 2020.
"Sydney is still in a very good position even with Delta and that's because [some] people are vaccinated – up to 90 per cent in aged care where many of the deaths came from in Melbourne," he said.
"That high vaccination rate gives those people protection from Covid."
There have been 10 deaths linked to the current Sydney outbreak so far. But he expected that overall Sydney will see a lower proportion of fatalities than Melbourne did last year when 800 people passed away.
In addition, the numbers in Sydney are also nowhere near Melbourne's peak of 650 plus, meaning the city has less to do to get back towards zero. It took Victoria about three weeks to get from its peak rolling average of 400 or more cases to the around 100 currently in NSW.
If Sydney is destined to follow Melbourne's trajectory, then cases should begin falling consistently this week.
If that doesn't happen, then Sydney could be in for a very different outbreak.