The state's health officials said 18 locally-acquired cases were detected across the state in the 24 hours to 8pm on Thursday night from 48,402 tests.
NSW Health said there were six more cases of community transmission found since the 8pm cut-off.
Fears are mounting that millions of Sydneysiders may soon be confined to their homes as the highly infectious Indian strain of Covid spreads across the city, as an expert revealed the three key factors that could keep the city out of lockdown.
The uncertainty gripping the Government comes as NSW Health Minister Brad Hazzard and four other MPs are forced into isolation after being close contacts of Agriculture Minister, Adam Marshall, who has tested positive to Covid.Insurance Loans Mortgage Attorney Credit Lawyer
Mr Hazzard believes Premier Gladys Berejiklian is 'fairly safe' from becoming infected, although discussions were underway about closing Parliament. The parliament's whips sent notes to MPs members urging them not to bring in staff before both houses sit on Thursday.
Epidemiologist Dr Abrar Chughtai said whether Sydney would be sent into lockdown would hinge on three key factors - vaccination levels, the nature of the Covid-19 strain being spread and how active the cases were in the community.
'If all cases are close contacts and you are able to trace all contacts of those cases, then you probably don't need lockdown,' he told ABC News.
Queensland on Thursday recorded three new local cases after an infected woman in her 30s visited the Portuguese Family Centre restaurant in Ellen Grove in Brisbane's south-west.
Sixteen new infections were announced in NSW on Wednesday, bringing the total to 36 new community cases in the Harbour City after a super spreader event saw 10 people infected at a birthday party, which was attended by 30 people.
Ms Berejiklian said on Wednesday she did not want to impose a debilitating lockdown unless she had no other option.
'I am not going to rule out further action, I am not going to rule out what happens beyond a week,' she said.
But sources close to the Berejiklian government have hinted Thursday will see 'big numbers' of new infections, with Sydneysiders ordered not to leave the city.
Covid cases are on the rise in Sydney with sources saying Thursday will bring 'big numbers' (pictured, a couple in mandatory masks in Manly)Insurance Loans Mortgage Attorney Credit Lawyer
NSW Premier Gladys Berejiklian (pictured on Wednesday) has so far managed to fend off a lockdown, instead bringing in restrictions including limited visitors to the home and mandatory masks - even in offices
Ms Berejiklian, who has always strived to take a measured approach to outbreaks, has so far stood firm by refusing to lock down Sydney, instead bringing in a number of restrictions including limits of five visitors to a household and mandatory masks.
In the face of a growing number of cases, a senior health source admitted to Daily Mail Australia that the trend of infections is 'not good'.
When asked about a potential lockdown, the source said: 'It certainly looks like that's where we are heading.'
Four new mystery infections have contributed to widespread speculation that the city will be locked down by the end of the week, with sources telling the ABC and 7 News such restrictions could be imminent with a big spike in cases to be announced.
The city's vaccination levels
The transmissibility of the Covid-19 variant
How active the cases were in the community while they were infectious
Source: UNSW epidemiologist Dr Abrar Chughtai
The Indian variant is so contagious that two people in Bondi this week caught Covid by momentarily brushing past each other.
While other premiers have locked down state capitals after just two cases, Ms Berejiklian has always tried to strike a balance between public health and economic and mental wellbeing.
But she conceded that approach may have to change if cases begin to spiral out of control, particularly those not linked to known outbreaks.
'We have always said we will not burden our citizens unless we absolutely have to,' she said on Wednesday.
'If we need to take further action within the week or after the week, we are open to that.'
Her close ally NSW Health Minister Brad Hazzard has rubbished claims that a lockdown is imminent, saying they have 'zero' truth to them.
'No plan to lockdown contrary to reports this evening,' Mr Hazzard told news.com.au on Wednesday night.
'Measures implemented this afternoon are proportionate and appropriate. Reports of a lockdown are greatly exaggerated.'
Those who live and work in seven hotspot suburbs will not be allowed to leave metropolitan Sydney unless they have an essential reason
Prime Minister Scott Morrison praised the NSW's premier's approach.
'She hasn't gone to lock down Australia's biggest city,' he said.
'But has taken the positive decision to keep Sydney and NSW open for its residents and to continue to rely on what is Australia's best contact tracing system.'
On Wednesday evening, NSW Health added 12 stores, a busy bus route and three train lines to the burgeoning list of exposure sites in the city. Pictured: Passengers at Sydney Domestic Airport
The outbreak has forced Ms Berejiklian to bring in new restrictions, including banning people from metropolitan Sydney from leaving the city, but she stopped short of shutting down businesses.
Her interstate counterparts were quick to slam their borders shut to residents amid the latest outbreak, ruining travel plans for many over the school holidays, which begin on Friday.
Queensland's premier Annastacia Palaszczuk has rushed to declare all of Sydney a Covid-19 hotspot, slamming the borders shut to millions.
Lockdown-happy premiers in other states including Western Australia , Victoria and Queensland have already slammed their borders shut, disrupting school holiday plans for thousands (inset, the Sydney suburbs deemed 'hotspots')
The move came after draconian moves by Western Australia and South Australia, which have shut the border to the entire of New South Wales.
In Victoria, people from seven local government areas are banned from the state - City of Sydney, Waverley, Woollahra, Bayside, Canada Bay, Inner West and Randwick.
The majority of the 16 new cases stem from a birthday party on Saturday in West Hoxton, in western Sydney, which included an infected Bondi Junction Westfield worker.
The woman was not suffering any symptoms at the time, but was tested the next day when they developed and received a positive result on Monday.
Passengers are seen lining up to check in at Sydney Domestic Airport on Wednesday as states rushed to shut their borders
All party attendees were ordered into self-isolation, with eight partygoers who came forward for testing on Tuesday found to have contracted the virus.
This includes a two-year-old child who attended Little Zak’s childcare in Narellan Vale, near Campbelltown, on Monday.
NSW Health added 12 stores, a busy bus route and three train lines to the burgeoning list of exposure sites in the city late on Wednesday evening.
New venues included three eastern suburbs supermarkets, a TAFE building in Meadowbank, and an office building on Pitt Street in the CBD.
From 4pm Wednesday for one week:
Visitors to households will be limited to five guests – including children;
Masks will be compulsory in all indoor non-residential settings, including workplaces, and at organised outdoor events;
Drinking while standing at indoor venues will not be allowed;
Singing by audiences at indoor shows or by congregants at indoor places of worship will not be allowed;
Dancing will not be allowed at indoor hospitality venues or nightclubs however, dancing is allowed at weddings for the bridal party only (no more than 20 people);
Dance and gym classes limited to 20 per class (masks must be worn);
The one person per four square metre rule will be re-introduced for all indoor and outdoor settings, including weddings and funerals;
Outdoor seated events will be limited to 50 per cent seated capacity;
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