How insidious Covid-19 Delta strain spread so far, so fast, in Melbourne

It‘s a classic Melbourne story of footy – Aussie rules, soccer and rugby – and a funky restaurant, played out over just 72 hours.

The Crafty Squire pub in Melbourne. Picture: Rebecca Michael.

It‘s a classic Melbourne story of footy – Aussie rules, soccer and rugby – and a funky restaurant, played out over just 72 hours.

Those most innocent of pursuits in the life of a fit eastern suburbs teacher in his 30s have resulted in dozens of Victorians being infected with coronavirus, and helped plunge seven million people into lockdown.

As one of very few Delta strain outbreaks in the world with which contact tracers have so far been able to keep pace, Victoria’s Maribyrnong cluster offers unique insights into the transmission patterns associated with the notoriously infectious variant which has three states locked down.

The tale begins on the afternoon of Saturday, July 10, when the Trinity Grammar teacher headed to the MCG to watch Geelong play Carlton.

Among the crowd on Level 2 in the MCC members reserve was a highly infectious man in his 60s.

Just two days earlier, the older man had caught the virus from three Sydney removalists as they helped his neighbour move out of a third-floor apartment in the Ariele complex in Maribyrnong, in Melbourne’s west.

In the early hours of the following Monday, the Trinity teacher headed out to catch Italy’s victory over England in the Euro soccer final. He had no idea he was among 14 people now known to have been infected at the AFL game.

But less than 36 hours after the final siren at the MCG, he transmitted the virus to a fellow patron among a crowd of more than 400 watching the soccer match between 3am and 8am at the Crafty Squire pub in Melbourne’s CBD.

He spent the rest of the day at work in the classroom, unwittingly setting off a new chain of transmission in which at least 22 staff, students and household contacts of the Kew school were infected. Thousands more have been isolated, including families associated with nearby Ruyton Girls’ School and Methodist Ladies’ College.

The following day – Tuesday, July 13 – the teacher headed out for dinner as one of a party of 12 at the Ms Frankie restaurant in Cremorne. The venue has been repeatedly praised by health authorities for exemplary use of the QR code check-in system, but by Friday 33 cases had been linked to it, among staff, patrons and household contacts. One staff member managed to catch the virus on the Tuesday and pass it on to patrons on the Thursday, despite having worn a mask for both shifts.

Having finished his Ms Frankie dinner, the teacher headed to the final match in his footy code medley: the Wallabies rugby union clash against France at nearby AAMI Park. There he infected at least seven people, including at least two initially classified as Tier 2 contacts, because they had not been sitting near him.

It has since emerged that they likely caught the virus during brief contact with the teacher at “pinch points” at Gates 6 & 7 on their way into the ground.

In a demonstration of the insidious nature of the Delta variant, one of these people initially tested negative for the virus, and was released into the community.

Following a reclassification of his exposure, he returned to quarantine, but not before potentially exposing more than 900 people at busy Prahran Market in Melbourne’s inner southeast last Saturday, ahead of a positive test on Wednesday.

For his part, the Ariele resident in his 60s unwittingly spread the virus to more than 20 direct contacts during just four engagements.

These include his parents aged 89 and 90, a social contact, and patrons at the Young & Jackson pub in the Melbourne CBD on his way to the MCG.

His footy outing on July 10 took place in the company of a friend in his 50s who lives at Barwon Heads, 110km southwest of Melbourne near Geelong, and works at Bacchus Marsh Grammar, 60km west of Melbourne.

Ten cases have been linked to Bacchus Marsh Grammar, and four to the Barwon Heads family, including one of two people who was in intensive care with the virus on Friday.

The stop at Young & Jackson resulted in the infection of four other patrons, two of whom have started their own clusters of three and four cases respectively on the West Gate Tunnel road project and at a cabinetry business.

Another Young & Jackson case was a student in her 20s who subsequently flew to Queensland. Other clusters linked to the MCG include 10 cases sparked by a nine-year-old at St Patrick’s Primary School in Murumbeena in Melbourne’s southeast, eight people linked to a group who spent three days holidaying together on Phillip Island, 140km southeast of Melbourne, and a household of four in Mildura, 540km northwest of Melbourne.

Such is the capacity for the Delta variant to rapidly and covertly spread far and wide, the vast majority of Victoria’s caseload of almost 150 people had already caught the virus before the state went into lockdown with 18 known cases on Thursday July 15.

The lockdown came just three days after the first cases emerged, and a week after the Sydney removalists had visited.

The inadvertent superspreading activities of the Trinity teacher and the Ariele apartments resident who gave him the virus account for all but 18 of Victoria’s 147 community-acquired cases as of Friday.