UPDATED: Two John XXIII high-school students have returned negative coronavirus tests, while a third student in Year 12 is awaiting results, the school announced. It comes after one of the children's parents tested positive to COVID-19 on Tuesday.
The school said it was maintaining regular contact with the family, who have reported they are all feeling well, John XXIII said on March 19.
John XXIII announced the parent tested positive to COVID-19 the same day an aged care facility is in lockdown after an employee returned to work following overseas travel and was later diagnosed with the virus.
The family of the John XXIII College parent then went into self-isolation, and the school remained open.
In a statement sent to parents on March 17, the college said it was taking measures to ensure the safety of students, staff and families and was following Catholic Education WA protocols.
"This development may make your child feel worried or anxious," the statement said.
"It is important to remember that you can help your child at this time, first by listening attentively to their concerns, and then by providing some reassurance.
"As a Catholic College, it is important for us to show care and support for all members of our community.
"I ask that you pray for our community members who are now having to self-isolate, and thank you for your support at this time."
According to the BNiQ database, John XXIII College is ranked as the 11th largest school in Western Australia with 1,558 students.
Meanwhile, an employee from a WA aged care facility and two health workers from Joondalup Health Campus have tested positive.
The three workers returned to work in Perth after contracting COVID-19 overseas, with one of them completing several shifts at an Aegis Aged Care Group facility before testing positive and prompting a lockdown.
An Aegis Aged Care Group spokesman told AAP the man worked at a transition facility in Bayswater before returning positive test results.
He was among 10 cases confirmed on Monday, when the facility was close to its capacity of 30.
"We are working closely with the Department of Health to ensure that all relevant tracking is taking place for all who may have had any contact with the staff member," a company statement read.
"No other Aegis facility is affected by this single COVID-19 case and we are maintaining our already strict infection control protocols."
The spokesman said no residents were currently showing any symptoms.
The two other infected healthcare staff work at Joondalup Private Hospital, and Health Minister Roger Cook said operator Ramsay Health Care would comment further.
Special testing arrangements have been introduced for healthcare workers with fever or flu-like symptoms.
Another aged care facility, Regis Aged Care, has announced all its facilities will enter into a lockdown period for two weeks, effective at 5pm today.
In a statement, the organisation said visitors would not be allowed and outings have been cancelled, but some internal lifestyle activities would go ahead, in line with social distancing recommendations.
New residents will be accepted, subject to them being well and going through a 14-day isolation period.
As of 1pm AWST today, 6,582 people in the state have been tested for COVID-19, and 31 positive cases have been recorded.
There are now 378 cases nationally and five deaths.
By AAP and Madeleine Stephens
