Breakthrough in Melbourne’s Mystery ‘Delta’ Cluster

Victoria’s concerning outbreak of the Delta strain of Covid-19 has been linked to a returned traveller, though questions still remain about how it leaked into the community. The Health department confirmed this morning (Tuesday).

Acting Premier James Merlino confirmed they have now found a genomic match between this cluster and a returned traveller who entered hotel quarantine on May 8 after arriving from Sri Lanka.

“While we have a genomic link, we do not currently have an epidemiological link, and further investigations are under way to see if we are able to establish any contact between the returned traveller and these families,” he said.

The outbreak, known as the West Melbourne cluster, now has at least 14 confirmed cases linked to it, all of which are the highly-infectious Delta strain.

A genomic link has been made between a person who was in hotel quarantine in Melbourne and the West Melbourne ‘Delta’ COVID-19 cluster.

However It remains a mystery how the virus was transmitted, with no known link between the returned traveller and positive cases.

The returned traveller tested positive to the virus the same day he arrived in Melbourne and was transferred from the Novotel Ibis quarantine hotel to the Holiday Inn health hotel on May 14 before being released from quarantine on May 23.

Investigations have so far revealed there were 24 people on the same plane as the case, with all crew and passengers testing negative.

Of the 268 staff who worked at the Ibis hotel on May 8 an 9 and the 360 staff at the health hotel, there were no positive tests identified. All 12 residents housed in the same Novotel Ibis have tested negative.

Deputy Chief Health Officer Allen Cheng said there were currently four main working theories.

1. The case transmitted to, or was infected by, another passenger or staff on the flight and that person has gone into the community (there were 24 people in total on the plane).
2. The case transmitted the coronavirus after serving 14 days in hotel quarantine.
3. The case unknowingly transmitted to a staff member on the plane, airport or hotels.
4. The case transmitted to another resident in hotel quarantine, who then took the virus into the community.