The Delta variant of Covid-19 circulating in Melbourne has been genomically linked to a returned traveller in hotel quarantine.
Acting Premier James Merlino confirmed public health teams had matched the strain to a man who arrived in Melbourne from Sri Lanka on May 8 and tested positive on the same day.
Genomic sequencing returned an “identical match” to the second of the two families at the centre of the West Melbourne outbreak, who have ties to North Melbourne Primary School.
“I can confirm today that we have now found a match between a returned traveller who entered hotel quarantine in Melbourne on May 8 and this cluster,” Mr Merlino said.
“While we have a genomic link, we do not currently have an epidemiological link, further investigations are underway to see if we are able to establish any contact between the returned traveller and these families.
“There’s currently no definitive understanding of where transmission events may have occurred but we are investigating all possibilities from the plane, to travel to the hotel.”
The man in his 40s, from the LGA of Glen Eira, was transferred from the Novotel Ibis quarantine hotel to the Holiday Inn health hotel on May 14, where he completed his quarantine and was released on May 23.
Acting Police Minister Danny Pearson said while investigations were ongoing, he could confirm there had been 24 people, including crew, on the traveller’s plane.
All other passengers and SkyBus crew tested negative to COVID-19.
Among the staff working at both hotels the man had stayed in, no positive tests have been reported, and all 12 residents on the same floor as the man in the Novotel tested negative.
“While we are continuing to review CCTV and incident logs again I can confirm that so far there is no reported or obvious breach of infection prevention control protocols or anything else that would indicate a transmission has happened inside the hotel,” Mr Pearson said.
Health authorities will follow up the man’s household contacts to ensure they did not get infected.
How the Delta strain could have entered the community
Victoria’s Deputy Chief Health Officer Professor Allen Cheng said there were several possibilities being investigated to establish how the Delta strain of COVID-19 entered the community.
The Delta cases among the second family at North Melbourne Primary School could be traced back to the returned traveller, but the “working hypothesis” is there may be a missing link.
“So what this does suggest is that there has been transmission either directly from person-to-person or indirectly via unidentified cases to the family and the community, or less likely perhaps, the source of infection for both cases, for example from another traveller from where this gentleman came,” he said.
“The investigation is continuing but there are four main theories and some of them are more or less likely.”