Household cluster sounds new alarm

A new mystery cluster of four cases in a household in Melbourne has prompted a backflip on plans to ease rules on masks outdoors.

People wearing masks on Chapel st, Prahran. Picture: Alex Coppel

A new mystery cluster of four cases in a household in Melbourne’s north has spooked Victorian health authorities, prompting a backflip on plans to ease rules governing the wearing of masks outdoors.

The about-face came despite an admission from Victoria’s Covid logistics chief, Jeroen Weimar, that there has been no evidence of outdoor transmission of the virus this year.

Victoria’s health department is also investigating a possible link between a coronavirus-positive couple who left the outer northwestern suburb of Melton on June 1 and travelled through NSW to Queensland, and a shopping centre in Melbourne’s outer north visited by nine other cases.

Victoria’s latest cases include a man in his 80s, a woman in her 70s, a man in his 50s and a man in his 20s who all live in the same household in Reservoir in Melbourne’s northern suburbs.

How they caught the virus remained a mystery on Thursday, with the man in his 80s the first to return a positive test result on Wednesday, followed by the others. Victoria’s health department said authorities had also tested “a number of high-risk primary close contacts of the cases outside of the household” and all had returned negative results, although no detail was provided on the nature of the “high-risk”.

Exposure sites visited by household members included a shopping centre in Bundoora and a service station in Thomastown on Monday, and a grocery store in Reservoir and Bunnings in Thomastown on Tuesday.

Ahead of an easing of Melbourne’s lockdown on Thursday night, Acting Premier James Merlino warned Victoria remained on “high alert” for undetected community transmission.

“I can confirm the easing of restrictions that we announced yesterday will proceed as planned from 11.59pm tonight with one small exception for Melbourne: masks will continue to be required to be worn outdoors in all circumstances,” he said.

Mr Weimar was asked if there had been any recent examples of coronavirus being transmitted outdoors in Victoria. “No. We have no evidence that we have seen in this … outbreak or the most recent ones, of outdoor transmission,” he conceded.

Acting deputy chief health officer Allen Cheng said instances of outdoor transmission had been confirmed during Victoria’s second wave of coronavirus last year.

“They’re not very common but they do occur. When there are active cases in the community, I think it’s a small thing to ask for people to continue to wear masks at all times when outside of home,” Professor Cheng said.

He said Victoria’s public health team estimated “perhaps 5 per cent” of cases in the second wave had been transmitted outdoors “but, again, it can be very difficult to tell”.

More than 24 hours after Queensland broke news of a positive test from a traveller from Victoria, and NSW issued a list of sites visited in that state, Victoria was yet to release details of any exposure sites.

The state’s health department said a contact tracing interview was ongoing late on Thursday.

The first member of the couple to test positive, a 44-year-old woman, is believed to have been infectious when they left home on June 1 and developed symptoms on June 3.

Contact tracers are investigating a potential link to the Craigieburn Central shopping centre, where one of the couple checked in on May 23, given nine other cases have visited the site during the current outbreak.