Queensland has recorded one new case of coronavirus overnight, bringing the state’s total number of active cases to 18.

The newest case is a relative of a previously confirmed case that was linked to the Brisbane Youth Detention Centre at Wacol. Five staff have tested positive, along with five family members, which Young said justified her decision to restrict the size of household gatherings last week.

Young urged Queenslanders living in the Greater Brisbane region, particularly in Ipswich, to start wearing face masks.

The Metro North, Metro South and West Moreton health districts will be urged to roll out masks across facilities and Young said people in the community should do the same.

“It’s time to use a mask,” Young said.

“I’m not going to mandate it because I don’t believe we have broad spread community transmission, but certainly we’re in a risky period at this time.

“If you’re in a crowded situation that you can’t get out of, put a mask on.

“[Keep] a bit of hand sanitiser in your back pocket or your handbag, and a mask with you.”

Only 16 staff at the centre have yet to be tested – no detainees have tested positive – and Young said it was hoped laboratory tests would help trace back the origins of the cluster.

“I hope to get that answer fairly soon,” Young said.

“We’re waiting on the genomic sequencing of these cases and the cases from Melbourne.”

Young said Brisbane and Ipswich had been declared a “restricted area”.

“It’s an area where I’ve put restrictions in place in terms of hospitals, gatherings and in terms of getting people to be alert to come forward and get tested,” she said.

Deputy Premier Steven Miles said health officials were “really worried” about the outbreak, hence the need for people to take precautions by wearing masks.

“We really hope that we are able to get on top of it as we have with other recent outbreaks but we won’t know really for a couple of weeks,” Miles told ABC Radio Brisbane.

“This is the largest number of community-acquired cases that we’ve had in months in Queensland and so we’re monitoring it very closely.”

Miles said anyone who had been to the areas listed in the current health alerts should not ignore minor symptoms.

“If they get the slightest tickle at their throat or a bit of a headache — any symptom at all, go and get tested,” Miles said.

“Often the symptoms of this virus, particularly early on, can be really, really mild.”

Premier Annastacia Palaszczuk said there was no need at this stage to tighten any of the restrictions or impose bans on certain activities. The Government continues to grant exemptions to cross the restricted border and has expanded eligibility to include farmers.

Queensland remained on high alert as Victoria recorded its lowest daily increases in cases since July 5, when 74 cases were reported. Overnight, 116 new cases were announced, along with 15 deaths.

NSW reported three new cases in the 24 hours to 8pm Sunday, including one locally-acquired case.