Six new exposure sites, including two KFC restaurants, have been identified by health authorities in Western Australia as the state attempts to snuff out any potential Covid-19 infection in the community.
The housemates were later identified as food delivery workers, with one performing more than 100 deliveries while infectious.
On Tuesday, the following exposure sites were identified:
7-Eleven service station, 102 Princess Rd, Balga, April 28, 7.45pm - 8.15pm
KFC Whitfords, 7P Cromer Grove, Hillarys, April 29, 10.40pm - 11.15pm
Caltex Whitfords, 470 Marmion Ave, Hillarys, April 29, 10.45pm - 11.20pm
Pizza Hut, Shop 6/981 Wanneroo Rd, Wanneroo, April 29, 7.15pm - 7.45 pm
KFC, 269 Eddystone Ave, Beldon, April 30, 5.15pm - 5.30pm
Coles Express, Ocean Reef Road, Marmion Ave cnr Marina Bvd, Ocean Reef, April 30, 5.15pm - 5.45pm
Anyone who visited the venues, or any of the previously identified locations, during the specified times must isolate until receiving a negative test, the Department of Health said.
Since the cases were announced on Saturday, there has been no further infections identified.
Last week's snap, three-day lockdown after the emergence of earlier cases gave confidence to health authorities the latest outbreak had not widely spread.
Mr McGowan avoided implementing another lockdown however mandatory mask-wearing both indoors and outdoors was reinstated, nightclubs were closed and and fans were prevented from attending Sunday's AFL western derby at Optus Stadium.
'No obvious reason' how Perth leak happened
The guard in his 20s worked at the Pan Pacific Hotel, where it's believed he contracted the virus from a returned traveller from the United States.
Mr McGowan said officials didn't know how the transmission had occurred, but insisted it was not caused by ventilation issues which had been detected in other quarantine hotels, three of which will close in coming weeks.
"As you've seen in other states, sometimes you'll never know," he told reporters.
"It appears that there's no obvious reason why it spread from one of those passengers to the security guard."
Health Minister Roger Cook said the guard had been stationed near a lift and it was possible the virus had spread through surface contamination.
Genomic testing has indicated the guard has the same US variant of the virus as two returned travellers who were staying on the same floor.
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