Western Australia's sixth case of coronavirus has been confirmed, just hours after health authorities detailed the state's first person-to-person transmission of COVID-19.

WA chief medical officer Andrew Robertson told reporters the latest case was the adult son of a woman who flew from Jakarta to Perth, spent six days in the city, then travelled to Melbourne.

Earlier on Monday, WA Health Minister Roger Cook said a woman aged in her 60s had contracted coronavirus from her husband after he returned from Iran in the past fortnight.

Australia imposed a travel ban on Iran on February 29.

"Community spread is an inevitability - it's a question of when not if," Mr Cook said.

WA's fourth case was confirmed on Sunday.

The woman, in her 70s, had returned to Perth from Cuba via London on Thursday, was tested the next day after suffering mild symptoms and went to a show at the Perth Concert Hall on Saturday, before the test returned a positive result.

UK comedian Russell Brand was supposed to perform at the same venue on Monday night but said on Twitter the show would be cancelled.

"I am not happy with risk for me or for any of you," he wrote.

"My apologies, I hope I see you soon."

The Department of Health has urged people undergoing testing to remain at home and self-isolate, with results taking up to 48 hours.

The state government will open COVID-19 clinics within Sir Charles Gairdner Hospital, Royal Perth Hospital and Fiona Stanley Hospital on Tuesday.