Frantic hunt for Melbourne Covid-19 ‘missing link’

Victorian health authorities are scrambling to find what they believe may be a ‘missing link’ after four people in Melbourne’s north tested positive for the coronavirus on Monday.

Police and Public Safety Officers enforce mask-wearing at Flinders Street Station in Melbourne following the new Covid outbreak. Picture: Andrew Henshaw

Victorian health authorities are scrambling to find what they believe may be a “missing link” after four people in Melbourne’s north tested positive for the coronavirus on Monday.

Thousands of Melburnians have been forced to quarantine after a swimming school in the city’s northeast and the busy Highpoint shopping centre were listed as exposure sites visited by members of the cluster — who are from the same family but spread across two households.

No direct link has yet been established between any of the four and a man in his 30s who returned three weeks ago to Wollert, on Melbourne’s northern outskirts, having contracted coronavirus in an Adelaide quarantine hotel.

However, state Health Minister Martin Foley said authorities’ “working thesis” was that the cluster was linked to the Wollert case, with genomic sequencing results expected to confirm or rule out that theory in coming days.

“The dates don’t line up immediately, so we can’t rule out if there is a missing link out there,” Mr Foley said.

The cluster comes after Victoria’s Health Department revealed on Friday that it had made a mistake almost a fortnight earlier when it declared Woolworths Epping, rather than Woolworths Epping North, as an exposure site the Wollert man had visited.

The revelation coincided with the detection of coronavirus fragments in sewage from the Epping and Wollert areas, with Mr Foley confirming on Monday that the wastewater result corresponded with the address of at least one of the new cases.

The cases have also emerged almost exactly a year after leaks from Melbourne quarantine hotels into communities of essential workers in Melbourne’s northern and western suburbs sparked Victoria’s second wave of coronavirus, which killed 800 people and prompted an 111 day lockdown.

Mr Foley said the first case to be diagnosed in the cluster of four was believed to have been infectious from May 18, eight days after the man from Wollert had gone back into quarantine in Melbourne after testing positive.

“In terms of incubation period, they don’t appear to cross over … and that fuels the thesis that there is perhaps a missing link,” he said.

“When that genomic sequencing is returned that will answer that question for us.”

News of the cluster first broke shortly after 10am on Monday, when Victoria’s Health Department issued an alert stating that two “likely” cases had been detected in Melbourne’s north.

On Monday afternoon, Mr Foley and chief health officer Brett Sutton confirmed that the first case in the cluster, an adult male who had developed symptoms on Thursday, had tested positive after visiting a testing centre on Sunday.

That man was accompanied at the testing centre by an asymptomatic adult male relative, who also tested positive.

Testing of close contacts through the course of Monday saw cases identified in a woman and a preschool-age child, with negative results returned from other family members.

The Jump swimming school in Bundoora between 8:55am and 10:15am on Saturday and Highpoint between 5pm and 8pm on Friday have been listed as exposure sites, with anyone who visited either venue at those times advised to get tested and isolate for 14 days or until further notice.

Health authorities were expected to list further exposure sites as contact-tracing interviews continued, with more specific information regarding affected venues within the large shopping centre also expected to be made public.

Professor Sutton said test results from the initial case in the cluster indicated that his viral load was “likely high”.

“With close contacts becoming positive, he’s likely (to have been) quite infectious,” he said.

Asked how contact tracers had listed the wrong Epping Woolworths as an exposure site for the Wollert case, Mr Foley said the man’s electronic bank receipts had listed “Epping Woolworths”.

“Where our team fell down is that it took us to the Epping Woolworths straight across the road from another primary exposure site, the Indian grocer. There is a Woolworths literally across the road,” he said.

“As a result of the wastewater positive last week, our team went back and went through all of that again … and that’s where, despite the banking app receipts saying Epping Woolworths, it was in fact Epping North Woolworths.”

Mr Foley said tests on all Epping North Woolworths staff had come back negative and there were no known links between the store and the latest cluster, but he was unable to rule out the bungle had contributed to the outbreak.

He urged Victorians to monitor for symptoms, get tested, ensure they used QR codes at public venues, get vaccinated if eligible and wear masks on public transport.