A Cairns man who works as a marine pilot, guiding ships through the Great Barrier Reef, has also tested positive – the risk to others is lower because he has been fully-vaccinated with Pfizer – along with two returned travellers in hotel quarantine.

Chief Health Officer Jeannette Young today said the 16 new community-acquired cases in the south-east had all been linked, and involved students, family members and close contacts. The outbreak started at Indooroopilly State High and Ironside State School.

The outbreak has now spread to 63 people, most of them children, and sparked a record turnout by Queenslanders to get tested. More than 50,000 tests were done in a 24-hour period, well above Young’s target of 40,000, which has also helped provide her with some reassurance there are not other clusters that have spread undetected.

While 10 of the new cases only came through during the night, and have yet to be examined by contact tracers, four had been in the community during their infectious period. That keeps alive the risk to others and means more exposure sites will be listed today.

Young said it was a good sign that two of the new cases had been in home quarantine the entire time they had been infectious. But she would still need all cases to be similarly contained, and linked, for the south-east lockdown to be lifted on Sunday.

Based on the experience with the Delta variant interstate, Young felt that “if we don’t do something really, really, really special in Queensland, we’ll be extending the lockdown”.

Authorities have again raised concern that residents and workers in the south-east should be doing more to comply with the lockdown, and even go further than required by health directives.

Police are already patrolling public areas and have started RBT-style traffic stops to check if people have a valid reason for leaving home. That is despite an already improved level of community compliance, and fewer people being on the roads and public transport. There have also been complaints of police being over-zealous.

After newspaper and social media reports of people engaged in non-essential shopping in south-east Queensland, Young implored people in the 11 local government areas not to look for loopholes in the directives, and rather use their better judgement to stay home.

“Last year, I didn’t have any problems with Bunnings being open and people going and buying some pot plants and doing some gardening,” Young said.

“But that was with previous variants. This is Delta, it’s so much more contagious.”

While Young has suggested major chains such JB Hi-Fi and Cotton On have no business being open during the lockdown – they do not provide an essential service – the State Government has not moved to force the issue and Deputy Premier Steven Miles suggested the onus was on consumers.

“The rules are pretty strict,” Miles said today, when asked if the directives should be tightened.

“You can’t go out because you need milk and stop to look at EB Games or JB Hi-Fi.”

Miles said if people stayed home this week, “next week you can buy all the sun-loungers you think you need”.

Brisbane’s annual show, the Ekka, has been cancelled for the second year in a row, and the local public holiday will also be postponed to later in the year. That will allow for a post-lockdown long weekend.

Young said the missing link between the current outbreak, and two overseas travellers who arrived on June 19, may never be known.

She said the Cairns man was believed to have contracted the virus from the crew of a vessel, however genomic sequencing showed no link to the outbreak so the search for connections would go further afield.

The man’s partner and child have not been infected but because he visited a local childcare centre it has closed for deep cleaning.

“Although I believe the risk is low, it is not zero,” Young said.

“There was enough virus to sequence, so there is enough virus to infect someone.”

With 100 active cases, and a large number of health workers in quarantine due to school links, Queensland Health has altered its policy of putting all active cases in hospital. Some, particularly the children with barely any symptoms, are now being allowed to remain at home under ‘virtual treatment’ if they present no risk to others.

Health Minister Yvette D’Ath said she hoped health workers remained safe but was confident those in hospitals and medical centres would rise to the challenge.

“It puts strain on the system but I know that our staff have trained for this, they have prepared for it, they know what to do,” D’Ath said.

D’Ath remains in negotiation with the Commonwealth to bring forward deliveries of Pfizer vaccine, and have more AstraZeneca distributed to pharmacies and GPs.