Queensland has breathed a sigh relief with Brisbane’s first night of home lockdown revealing no new community cases of the highly transmissible UK COVID-19 variant.

However the mutant strain has been detected in a woman from Victoria who arrived in Brisbane on a Jetstar flight on January 5.

Victorian authorities cleared her for travel after completing 10 days’ quarantine but she has since tested positive at her family’s Maleny home.

“This is very, very, very low risk but it is not zero risk, so we are just taking all of those precautions,” Queensland Chief Health Officer Jeannette Young said.

“However anyone in that area around Maleny or on that flight, if they develop any symptoms, could they please come forward immediately and get tested.”

Queensland remains on high alert after a cleaner at one of Brisbane’s quarantine hotels was initially diagnosed with the highly-infectious UK virus strain.

Authorities fear the woman in her 20s was infected and active in the community from January 2.

Residents in the council areas of Brisbane, Logan, Ipswich, Moreton Bay and Redlands must stay at home until 6pm on Monday except for essential work and shopping, exercise, to access healthcare or look after the vulnerable.

As Queenslanders eye a return to ‘normal’ life from Monday evening, Young was non-commital.

“We have to wait and see. I know it’s frustrating for people and I apologise for that but we have to take this day by day,” she said.

“Anything is a possibility but I won’t say how likely any scenario is. We’ve seen that at the moment down in Sydney with some very lengthy periods and then another case pop up. We just have to take each day and get the best information we can.

“The best information is when people are out there getting tested.”

The three-day lockdown prompted panic buying on Friday as crowds flocked to supermarkets stripping shelves of toiletries, perishables and canned goods with lines stretching for hundreds of metres.

Authorities continue to stress supermarkets will remain open and panic buying is unnecessary.

“I know some people are concerned that this may go beyond three days – irrespective, we have never shut our supermarkets,” said health minister Yvette D’Ath.

“For those who are lining up and hoarding food, can I say the only people who are going to suffer from this are our elderly people who will be getting anxious because they’re worried they might not be able to get food items who live from week to week.”

Masks also will be mandatory for people leaving home aside from children under 12 for the first time in Queensland.

Premier Annastacia Palaszczuk said there had been a fantastic repose with most people wearing masks and more than 14,700 tests in the previous 24 hours.

All 91 close contacts of the infected hotel cleaner have tested negative.

“Please continue to wear your mask if you are in the Greater Brisbane region. Please, everyone, stay strong and stay calm and we will get through this,” Palaszczuk said.

“We are monitoring the situation very closely over the next two days.”

Meanwhile, fragments of COVID-19 have been detected in sewage at four more Queensland sites: South Brisbane, Townsville, Hervey Bay and Maryborough.

“This does not mean we have new cases of COVID-19 in these communities but we are treating these detections with absolute caution,” Young said.

“A positive sewage result means someone who has been infected was shedding the virus. Infected people can shed viral fragments, and that shedding can happen for several weeks after the person is no longer infectious.”