‘No evidence’ family caught Covid in NSW

Health authorities are yet to determine how a Victorian family who holidayed in NSW contracted a strain of coronavirus not linked to any other local case amid concerns about the unknown source of the infection.

The strain – the more infectious Delta variant that originated in India – has been detected in the family of four who returned to Victoria from Jervis Bay, on the South Coast, last week and is a different variant to the other cases in the Melbourne outbreak.

Contact tracers are still to determine if the source of the variant is in Victoria, NSW or elsewhere and it is yet to be genomically linked to coronavirus cases in hotel quarantine. The mystery outbreak threatens to derail hopes of an early end to Melbourne’s lockdown. Victorian Chief Health Officer Brett Sutton said the family had tested positive to the Delta variant, known as B1.617.2, while other local cases in Victoria have been found to have the Kappa variant of the virus, known as B1.617.1.

Sutton said it was ‘‘within the balance of possibility’’ that the family had acquired their infection in NSW during their holiday. It was a very significant concern, Sutton said. ‘‘It has not been linked to any sequence cases across Australia from hotel quarantine or anywhere else.’’

But NSW Health Minister Brad Hazzard said there was ‘‘no evidence whatsoever’’ the family caught Covid-19 while in NSW.

‘‘No one knows where they got this, particular, precise [infection] from,’’ Hazzard told radio station 2GB.

Unlike Kappa, the variant at the centre of Melbourne’s outbreak, Delta is now considered a variant of concern by the World Health Organisation. Evidence suggests it is substantially more transmissible than the virus circulating at the start of the pandemic and is able to slightly reduce the effectiveness of vaccines.

The outbreak has put communities on the South Coast and along the Hume Highway on alert after the family from western Melbourne tested positive after visiting the area from May 19 to May 24.

Last month, an eastern Sydney man and his wife tested positive to the Delta variant. However, NSW Health confirmed there was no genomic link between that case and the Victorian family.