It started with a family of four: Rydges seeded 90% of Victoria's second-wave COVID cases
More than 90 per cent of COVID-19 cases in Victoria's deadly second wave have been traced to a family who arrived back from overseas in May and were quarantined at Melbourne's Rydges on Swanston hotel.
Dr Charles Alpren, an epidemiologist at the Department of Health and Human Services, told the inquiry into the state's hotel quarantine program on Tuesday that the rest of the cases could be traced back to three more travellers who were quarantined at the Stamford Plaza the following month.
The epidemiologist told the inquiry that Victoria's efforts to control its second surge of COVID-19 could have been improved by a better understanding of at-risk and marginalised communities and that although Victoria had a large scale testing program while the second wave developed, "you've got to test the right people".
Dr Alpren said he and his colleagues had been unable to pinpoint the exact "transmission events" at either hotel when the virus escaped from the quarantined travellers to staff, although "opportunities for transmission" had been identified.
Monday's hearings heard that returned travellers, quarantined the Rydges on Swanston and Stamford Plaza, were the source of more than 99 per cent of the state's current COVID-19 cases.
But the DHHS specialist provided more detail on Tuesday morning about how the outbreaks, which have forced Melbourne into a strict stage four lockdown and claimed dozens of lives, spread from returned travellers, via hotel workers and security guards and into the community.
Dr Charles Alpren said the Rydges hotel outbreak started with a family of four who arrived in Australia from south Asia on May 9 and who all fell ill and were diagnosed in the subsequent nine days.
The Rydges on Swanston hotel - the source of 90 per cent of COVID-19 cases in Victoria's second wave.Credit:Getty Images
On May 25, three members of staff, identified in Dr Alpren's evidence as a "mixture of Rydges employees and external staff", were then diagnosed with COVID-19.
When asked by a lawyer for Rydges if the external staff were government-contracted security guards, a DHHS lawyer objected to the question and the inquiry upheld the objection.
Dr Alpren referred in his witness statement to a suggestion that the family was taken by security guards for a walk outside the hotel on May 18, but there is no conclusive evidence that the virus was passed on during the walk.
By June, 17 staff members and people close to them, such as their family members, contracted coronavirus.
It all stemmed from the family of four, Dr Alpren said.
The Stamford Plaza outbreak has been traced back to a couple and another returned traveller.
The returned traveller – a man – returned to Australia from overseas and commenced mandatory quarantine on June 1, Dr Alpren said.
He became symptomatic the same day and was diagnosed with COVID-19 on June 4.
The couple returned to Australia on June 11 and were diagnosed on June 15 and 16.
The $3 million inquiry into the hotel quarantine system, set up by the Andrews government and led by former judge Jennifer Coate, also heard on Monday that DHHS advice to guards at quarantine hotels was "inappropriate" for use in a high-risk setting.
Asked for his view about what might improve the state's response to outbreaks of transmissible diseases, Dr Alpren said community understanding was crucial.
"There is nothing as far as case and contact tracing that beats local understanding," Dr Alpren said.
"Understanding the communities that are affected by whatever disease you are seeking to control is crucial to be able to bond with those communities and work with them to reduce disease transmission."
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