On Friday, Victoria state authorities said they had detected the highly infectious Delta COVID-19 virus strain for the first time in the latest outbreak in Melbourne, raising concerns over a major spike in new cases.

The World Health Organization (WHO) has classified the Delta COVID-19 virus variant under the four variants of concern due to evidence that they are highly contagious and spread more easily.

The Delta strain is likely responsible for causing the latest devastating outbreak in India.

Brett Sutton, Chief Health Officer, Victoria, told reporters in Melbourne, “It is a variant of significant concern. The fact that it is a variant different to other cases means it is not related, in terms of transmission, with these cases.”

He said the new strain had not been associate with any sequenced infections across Australia from hotel quarantine or elsewhere, according to Reuters.

Sutton said, “It is a concern that it is not linked to other cases but we are chasing down all those primary case contacts … and looking into where it might have been acquired.”

The new Delta strain was detected in two members of a family who traveled to neighboring New South Wales (NSW) two weeks ago while likely infectious and visited several popular tourist locations in the state’s south, per the news outlet.

The chief health officer explained that it was “within the bounds of possibility” that the cases could have contracted the Delta strain in NSW, adding that more tests are needed.

NSW is one of Australia’s most populous states, which has not reported any locally acquired cases in a month.

On the other hand, Victoria is battling to contain its latest outbreak of 64 cases since May 24 after reporting no cases for three months. The state has placed tough restrictions on the movement of people and shutting down large parts of its economy.

Public health officials have linked all the cases to a single traveler who was released from quarantine after testing negative.

Meanwhile, Melbourne is into its second week of strict lockdown after it was extended for another week until June 10. However, some restrictions have been eased in the state from Thursday night.

The officials have blamed the extension of tough restrictions in Melbourne on the Kappa COVID-19 virus variant, which was first detected in India.

Sudden lockdowns, regional border restrictions, and strict social distancing have played key roles in Australia’s efforts to curb the pandemic.

Nearly 20% of Australian adults have had their first dose of a COVID vaccine, with more than 4.8 million total shots administered so far. The article was published on Reuters.