Masks will be mandatory at all public indoor spaces and on public transport from 6pm on Thursday until 6am Tuesday, December 28.
The new restrictions come after an unvaccinated backpacker travelled from Queensland into Western Australia on December 12 when Queensland was classified as a 'very low risk' state – meaning he was not required to be tested prior to arrival.
The man arrived an hour before WA's border controls with Queensland were strengthened on Monday, December 13.
The backpacker started developing symptoms on Sunday, December 19 but did not get a test until Wednesday.
On Thursday morning the man tested positive to COVID-19.
His partner is also symptomatic and has been tested and moved into hotel quarantine along with four people he has been living with.
Premier Mark McGowan confirmed the four people had been camping in the Mandurah area.
A number of potential exposure sites have been identified across Perth, including in Mirrabooka, Joondalup, Girrawheen, Perth and the CBD, Subiaco, Northbridge and Scarborough – with more likely to be identified in the coming days.
A full list can be found at https://www.healthywa.wa.gov.au/.../Locations-visited-by...
Certain large-scale events have also been cancelled and nightclubs will be closed.
Dancing is banned except for weddings and anyone who has been in Perth and Peel since December 16 and enters another regional area is required to wear a mask in all indoor settings.
The Department of Health is working through the case and is in the process of identifying close and casual contacts, and locations visited.
People are asked to check the exposure sites list regularly and monitor their health and get tested immediately and self-quarantine, if they develop symptoms.
"This is a very concerning situation and over the next few days it is more important than ever for the WA community to follow the health advice and do everything we can to minimise community spread," Premier Mark McGowan said.
"The individual involved has visited a number of locations including nightclubs and events with hundreds of people.
"We've done it before, the WA community has banded together at difficult times like this, and we've seen it through together."
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