Spread of UK coronavirus variant limited to close contacts

Despite Daniel Andrews’s cliams the UK virus variant is ‘hyperinfective’, it has has infected no one other than close contacts of the Holiday Inn.

The Holiday inn on Flinders Lane in Melbourne. Picture: David Crosling

Victorian Premier Daniel Andrews says the UK variant of COVID-19 is “hyperinfective” and travels at “light-speed”.

Yet the coronavirus mutation has infected no one other than close contacts of cases linked to the original source of the latest outbreak, the Holiday Inn at Melbourne Airport.

At crucial points in the ­decision-making process over how to manage the cluster, the Victorian government assumed the virus may be spreading un­detected, with asymptomatic cases seeding further spread. But as it happened, infected cases visited a large number of exposure sites without spreading the virus.

The Holiday Inn cluster — which as of Friday comprised 22 cases linked to 3515 primary close contacts — is believed to have begun when a 38-year-old man used a nebuliser to inhale asthma medication on February 3 and 4.

Late the following Sunday, February 7, an authorised female officer in her early 50s became the first Holiday Inn worker to test positive for the virus.

Despite the woman visiting a series of locations in Melbourne’s west over the course of the weekend, the only community member she is believed to have infected is a member of her household who tested positive in the early hours of February 12.

Two days later on Tuesday February 9, a guest who had been staying opposite the nebuliser user and his family tested positive, as did a female food and beverage ­attendant who had been working on the floor. Despite visiting a ­series of exposure sites for several days before testing positive, the only person to whom the food and beverage worker transmitted the virus is her male spouse.

On Wednesday February 10, a second former hotel resident and a second female food and beverage attendant tested positive despite having returned a negative swab during her last shift on February 7. This food and beverage attendant transmitted the virus to her male spouse — a cleaner who tested positive on February 11 after visiting several sites across Melbourne, none of which has since been linked to any transmission.

The second food and beverage attendant and cleaner also lived with a female worker at Melbourne Airport Terminal 4’s ­Brunetti cafe, who would test positive on February 11. All three had attended a private dinner at ­Coburg function centre in Melbourne’s north on February 6, to which nine positive cases have since been linked.

It was on the night of February 11 that the Andrews government and Victorian health authorities — not yet aware of the Coburg gathering — held urgent talks to decide whether to impose a snap lockdown on Victorians.

Weighing on their mind was the case of the Brunetti worker, who worked at busy Terminal 4 from 4.45am to 1.15pm on Tuesday, February 9, as up to 2500 interstate travellers passed through on their way to destinations as far afield as Cairns in far north Queensland, Mount Gambier in South Australia, Merimbula on the NSW south coast, and Burnie in Tasmania.

The reality is that, had Victorian health authorities moved rapidly to isolate the households of all Holiday Inn workers — or even just those of the workers on the ­affected floor — as soon as they became aware of the first case on the Sunday, the Brunetti worker would have been isolating at home on the Tuesday and not at work.

It was not until the Tuesday afternoon, after her shift, that authorities moved to classify all Holiday Inn workers as close rather than casual contacts, and ­required all their households to quarantine.

Following the announcement of the lockdown, the first person to test positive was a man in his 30s from Point Cook, in Melbourne’s southwest, whose positive swab was returned late on February 12. The man was the first case identified with a connection to the February 6 Coburg private function.

The following day, Saturday February 13, a three-year-old child who had visited a kindergarten, an early learning centre and two public swimming pools and a woman who had visited the Queen Victoria Market while likely infectious became the fifth and sixth attendees of the Coburg function to test positive. The child’s mother — a mental-health practitioner with more than 150 primary close contacts across three Melbourne hospitals — tested positive last Sunday, despite having returned two negative tests and one weak positive previously.

On Monday two more Coburg guests who were household contacts of other members of the cluster tested positive, and on Friday, results were publicly confirmed for a parent and child who had been quarantined not far from the man with the nebuliser on the third floor of the Holiday Inn.

The child’s other parent, with whom they had been living since exiting quarantine, also tested positive.

Despite the rhetoric of the ­variant moving at “light-speed”, microbiologist and infectious diseases physician Peter Collignon said it was not a surprise that the UK mutation spread only among close contacts of confirmed cases.

“This variant has not behaved any differently to any of the other strains,” Professor Collignon said.

“The closer and more prolonged your contact with somebody, the greater the risk. But generally, the reputation for this UK strain outstretches its actual ability to transmit.”

Professor Collignon said in retrospect, the Melbourne lockdown was unnecessary.

“From my perspective, if you’ve got very little community transmission, I’m not sure that a short lockdown achieves much extra, if you’ve got good contact tracing and good testing,” he said.

“If I look at the lockdowns done in Adelaide, Brisbane, Perth, and now Melbourne, it didn’t turn up one more case than contact tracing did.

“The UK strain has not spread uncontrollably and wildly.”