Sydney is on high alert as large-scale Covid-19 testing regimes place residents on standby for a potential second wave.

A slew of Sydneysiders lined up in their cars in Casula, in the city's southwest, on Saturday to determine whether confirmed cases from a pub had spread.

Health authorities confirmed on Friday two people who attended the Crossroads Hotel in Casula on Friday, July 3, were infected with the virus, prompting a pop-up testing clinic in the pub's carpark.

A man from the Blue Mountains tested positive, NSW Health confirmed on Saturday morning, and three members of his household subsequently returned positive results.


The diagnoses follow another woman catching the disease on the same night.

Their visits to the pub have been declared the "only known link".

Nineteen-year-old Sid Rao, who was at the pub for an after-work drink on the same night, said the incident had added to fears a second lockdown coming for Sydney and NSW.

"I was a bit worried at first," he said.

"A second wave looks like it is happening if it keeps going on like this."

Rao, who works in warehousing, noted the frequency of travel between Melbourne and Sydney would likely have resulted in new cases turning up in NSW.

It is understood pub patrons who've been tested will be told in the next 72 hours whether they have a positive result.

Potential fears of second wave come as 216 additional cases were confirmed in Victoria on Saturday, and seven new cases were recorded in NSW.


Getting tested with her father, Gissella Martinez said she wanted to double check whether she had contracted the virus before setting off to the snow next week.

The 21-year-old from Liverpool said her father had visited the Crossroads pub the night of the two confirmed cases.

"I was a bit shocked," she said. "There was more apprehension about the testing itself rather than knowing if we have it, just because we haven't presented any systems yet."

Martinez, who works in recruitment, told NCA NewsWire she was scheduled to return to her office in the next couple of weeks.

"Despite me working from home, I would just have to flag with them that I would not be able to leave the house," she said.

Martinez also believes the cases popping up in NSW are pointing to a likely second lockdown.


"I think it is more likely than not that there will be second wave," she said.

Anyone who attended the hotel on July 3 is urged to self-isolate, look out for coronavirus symptoms and get tested.

Victoria has reported 273 new cases of coronavirus after a shocking week of record new daily numbers for the state.

The man in his 70s also died overnight, taking the national death toll to 108.

It comes as a cluster of eight coronavirus cases has been recorded among staff at The Alfred Hospital in Melbourne.

The hospital says the cluster includes five cases acquired through community transmission and three cases detected through contact tracing.


It's the second time the hospital had reported a cluster of cases during the pandemic — the first time was at the beginning when a cluster was detected in March.

Currently no patients have contracted the virus through the hospital.

The hospital has now put in place a concierge at the entrance of the Infectious Diseases Ward and the cleaning efforts have been increased.

It comes as dozens of patrons and staff were placed into lockdown after two pubs in Bordertown, South Australia, were exposed to a potential coronavirus case on Friday night and Defence Force personnel arrived at the Victoria-South Australia border to assist police at checkpoints.