West Australian contact tracers are working to ring fence any COVID-19 infection spread from a hotel quarantine security guard and two of his housemates.

The Perth and Peel region is on standby for another lockdown, depending on health authorities’ risk assessment of infection spread through the community.

Premier Mark McGowan says the guard in his 20s worked at the Pan Pacific Hotel between April 24 and 26 and tested positive on Saturday.

On his days off work from April 27 to 30, he moved through the community going shopping, seeing friends and visiting Mirrabooka Mosque.

After a weekly routine PCR test on Friday, a positive COVID-19 test result was received on Saturday morning, prompting the guard and his seven housemates to be moved immediately to hotel quarantine.

The guard had received his first dose of the Pfizer vaccine just days earlier.

Two of his housemates – a roommate and a guest from Canberra – also returned positive tests on Saturday.

Mr McGowan did not impose a lockdown on Saturday, but warned that could change by Sunday or Monday.

“We are effectively in a holding pattern and I hope we can avoid going back into lockdown,” he said.

The premier said health authorities had asked for time to conduct contact tracing over the weekend.

The early detection of the cases, combined with WA’s interim restrictions following a snap three-day lockdown last weekend, were the factors that justified holding off on another lockdown, the premier said.

On Saturday, authorities were more optimistic than they would otherwise be because of attendance limits at venues, takeaway at eateries, and mask rules.

All Perth and Peel residents must wear masks indoors and outdoors, regardless of proximity to others.

The security guard, dressed in PPE, worked on the same floor as two travellers – one from the US and one from Indonesia – who were transferred to the Pan Pacific Hotel on April 24 and tested positive.

“CCTV vision is being reviewed, however there is no clear explanation at this point as to how this security guard could have been infected,” Mr McGowan said.

He asked residents to get tested if they were exposed to the security guard at any of the locations he visited while infectious.

The locations the guard visited are listed on the healthywa.wa.gov.au website.

Any exposure sites relating to the two COVID-19-positive housemates are yet to be published, however authorities are most concerned about the security guard because he would have been infectious for longer.

Mr McGowan said he’d been told the security guard had been “very responsible”.

-AAP