Brisbane hospital Covid-19 outbreak: missing link found

COVID-19 contact tracers have found the ‘missing link’ in a transmission chain that sent Brisbane into lockdown for three days.

Queensland Chief Health Officer Jeannette Young in Brisbane on Friday. Picture: Tertius Pickard

COVID-19 contact tracers have found the “missing link” in a transmission chain that sent Brisbane into lockdown for three days, reinforcing belief that the outbreak peaked before Easter.

The mystery of how the virus skipped from a doctor at Princess Alexandra Hospital to a 26-year-old landscaper with whom she could not possibly have had contact was solved when a third nurse from the hospital was belatedly identified as a COVID carrier.

Her boyfriend was part of the circle of friends forming the so-called northside infection cluster, Queensland Chief Health Officer Jeannette Young revealed on Friday. The nurse had been infected by a “superspreader” returned traveller from Europe who also gave the virus to the doctor on March 10 but, being asymptomatic, had no inkling she was contagious.

The virus was not detected in the community until last Thursday week, March 25, after the landscaper from Stafford became ill and tested positive. The young man’s brother and three associates went on to get it but Dr Young said serology results showed the nurse was “definitely the missing link”.

“She’s treated the same patient that the doctor who got infected treated,” Dr Young said. “So it’s clear that’s how she got it and she transmitted it to her partner and it moved into that circle of friends and colleagues.”

The nurse’s historical infection – testing showed she retained no live virus – was the only locally acquired case to emerge on Friday, after Premier Annastacia Palaszczuk sounded the all-clear for Brisbane to come out of lockdown. Traffic was snarled to both the Sunshine Coast and Gold Coast as thousands of holidaymakers hit the road.

The risk of lifting the stay-at-home order less than halfway through COVID’s 14-day incubation period appears to have paid off, with Dr Young voicing confidence the outbreak had been contained.

She said the eruption of a second cluster, centred on the contagious PA Hospital nurse who participated in a hen’s party at Byron Bay last weekend, tipped the scales to locking down the Queensland capital. The nurse had evidently been infected by a returned traveller from India admitted on March 22.

Six of the 10 women who travelled from Queensland to the northern NSW beach town for the celebration, including the nurse’s sister, as well as a male entertainer from the Gold Coast, contracted the virus along with a local man who tested positive on Wednesday. This forced the NSW government to cancel the Byron Bay Bluesfest music festival for the second year running.

The other contagious PA Hospital nurse is believed to have got the virus from the Indian patient – possibly indirectly through a surface transfer – before infecting her flatmate, tying them to the hen’s party cluster.

Dr Young said her alarm grew as contact tracing and genomic sequencing of the cases unravelled the spider’s web of connections. “So (for) the first cluster, I didn’t recommend to the Premier that we needed to lock down,” she said on Friday. “I felt we could just work through it. But then to get a second cluster that’s an enormous amount of risk … too risky.”

Dr Young said it was an “enormous relief” that the missing piece of the puzzle had been found, filling in the gap between the infection of the PA Hospital doctor and the northside group.

“When you don’t know the links, when you know there’s still something out there, you just never are … sure what else could be going on,” the CHO said. “What other chains of transmission, what other friendship groups there could be. What other venues?”

NSW reported no new locally-acquired cases on Friday, easing concern the hen’s party cluster involving the highly infectious UK variant of the virus had seeded a severe outbreak in Byron Bay.

Ms Palaszczuk stepped up her campaign for overseas arrival numbers to be cut, announcing that another seven cases had emerged in hotel quarantine in Brisbane overnight. She would pursue the risk this posed to the community with Scott Morrison and the premiers at national cabinet next week.