Genome sequencing has linked the guard’s infection to a returned traveller who was in quarantine at the Marriott Hotel at Circular Quay and tested positive on Aug. 2.
NSW chief health officer Kerry Chant says the guard worked at Sydney’s Flemington Markets and Parramatta Local Court while infectious.
The guard also worked at the Marriott on Aug. 3, 4, 7 and 8 but was not infectious at the time and developed symptoms on Aug. 11.
“The exact nature of how that infection could have been acquired is a matter that’s under intense investigation,” Chant said on Aug. 18.
It comes as the inquiry into Victoria’s bungled hotel quarantine program heard 99 percent of the state’s current COVID-19 cases can be traced back to the Rydges or Stamford hotels.
At the time of the Rydges outbreak, there were few other cases of COVID-19 in Victoria and just 19 people had died from the virus.
Melbourne is now living under tough stage four lockdown restrictions and the state’s death toll is 351, with 7274 cases active.
But Chant says what has occurred in NSW is not a breach and the strain identified in the guard is different to the Crossroads Hotel cluster and other outbreaks in Sydney that are linked to Melbourne.
“We haven’t had evidence to date of other cases but, let me tell you we’re not going to leave any rock unturned in terms of our search for confirming there are no further cases linked to (this) single case.”
“I think it’s important that we keep a perspective on this,” she told reporters.
Close contacts of the guard have been identified and placed in to isolation. None have tested positive to the virus.
Casual contacts are being advised to monitor for symptoms.
All police and security guards at the Marriott have also been tested, with the officers returning negative results.
Authorities are waiting on results for half of the security guards.
NSW Police Assistant Commissioner Leanne McCusker said the quarantine program had accommodated 47,000 returned travellers since March 29 “with no community transmissions.”
“What has occurred over the last couple of days is no doubt concerning,” she said.
It comes as the state recorded three new cases of coronavirus in the 24 hours to 8 p.m. on Aug. 17, the lowest daily number in more than a month.
They were diagnosed from 13,736 tests in the 24-hour period, compared with 10,806 tests and seven positive cases in the previous 24 hours.
Two of the new cases, from southwest Sydney, were locally acquired. The other is a returned traveller in hotel quarantine.
One of the locally acquired cases is a close contact of the funeral gatherings cluster, bringing the total cases associated with that cluster to 73.
The other local case is from a growing number with no known source, which is concerning authorities.
By Tiffanie Turnbull in Sydney