Thousands of Sydneysiders will potentially have to self-isolate for two weeks after a pub employee became one of the latest cases in an emerging coronavirus cluster.

The 18-year-old employee was confirmed on Sunday as the sixth case linked to The Crossroads Hotel cluster.

NSW Health later updated the number to nine, with confirmed infections in a south-western Sydney woman in her 50s linked to the worker, a woman in her 40s who dined at the hotel on July 3, and a Victorian man in his 20s who dined there on the same night.

The earlier news of the sixth case led authorities to vastly expand their requirement for about 600 patrons who were at the pub on July 3 to self-isolate, to include everyone who entered from July 3 until the pub was closed on July 10.

The original case is still not known, NSW chief health officer Kerry Chant said.

BREAKING: Nine COVID-19 cases now linked to the Crossroads Hotel, Casula #nswpol #auspol #qldpol #COVID19Aus #covid19australia #coronavirusNSW pic.twitter.com/LItWKW7aFI

— COVID19 NSW (@Covid19NSW) July 12, 2020

“We do not think the staff member was the source,” Dr Chant said on Sunday.

“He worked for a number of days. He did work on the 3rd [or] on subsequent days.”

Five earlier cases had previously been linked to the pub: Two patrons who visited on July 3 and three close contacts of one of those people.

None is linked to Victoria’s outbreak.

Some 1200 people have been tested at the pop-up clinic in the pub car park since Friday.

https://twitter.com/JodiMcKayMP/status/1282167955321577475

Dr Chant said all Crossroads patrons and staff should get tested as a precaution and self-isolate until 14 days after their last visit.

“Even if you get a negative test, that does not mean you are out of the woods,” she said.

“A negative result does not mean you can breach self-isolation.”

Deputy CMO Dr Nick Coatsworth notes the Crossroads Hotel, Casula, is frequented by freight truck drivers. Asks freight drivers to be vigilant; that they not stop at such places if they have symptoms of infectious respiratory disease, & that they get tested for COVID19 if they do.

— COVID19 NSW (@Covid19NSW) July 12, 2020

Premier Gladys Berejiklian said NSW was on high alert for community transmission of COVID-19.

“I get extremely concerned and upset when we see people flouting the rules that are in place because that will take us down the path of Victoria,” she said.

“If you wake up with a scratchy throat, don’t go to work. Get tested and stay home.”

The pub outbreak highlighted the importance of businesses recording contact details for every sit-down customer and people taking measures seriously, Dr Chant said.

“When you do go into cafes, restaurants and other facilities, there is a reason we ask you for those details,” she said.

“Please use correct numbers [and] write legibly because this will be in your best interest.”

Crossroads patrons should get tested and self-isolate, NSW Health says.

Pop-up clinic is at the pub but there are also clinics at Campbelltown, Fairfield and Liverpool hospitals

— Luke Costin (@LukeCostin) July 12, 2020

The pub employee’s positive result was returned late on Saturday, meaning he’s not yet included on NSW’s official total of 3289.

Five new cases were officially added on Sunday: The three household contacts of a Crossroads patron and two returned travellers.

Another case was removed after expert analysis.

Ms Berejiklian also announced on Sunday that NSW would begin charging international arrivals for their mandatory 14-day stay in hotel quarantine.

From Saturday, for all arrivals on tickets bought from midnight Monday, the first adult in each travelling party will be charged $3000.

Subsequent adults will be billed $1000, each child $500 while kids under three will continue to be free.

Exemptions will be permitted in some circumstances.

-AAP