South Australia orders six-day statewide lockdown against fresh virus outbreak

South Australia announced a six-day lockdown of the state on Wednesday to stamp out a fresh coronavirus outbreak that has now expanded to 22 cases.

As of midnight, a series of wide-ranging mobility restrictions will be imposed on homes and businesses for six days to allow "breathing space" for contact tracing, South Australia state Premier Steven Marshall said.

The lockdown will mean people will be restricted from going outside of their homes, with only one person per household allowed to leave each day, but only for specific purposes.

Masks will be required in all areas outside of the home.

All schools, takeaway food, pubs, cafes and universities will be closed, along with the construction industry, which has been allowed to operate during past lockdowns in Australia.

Aged care and disability residential facilities, some of the most vulnerable to coronavirus, will be locked down.

Weddings and funerals will be banned, along with open real estate auctions and outdoor exercises. Factories other than food and medical products will be closed.

Regional travel is also not approved and FIFO (fly in fly out) resource work will be stopped for six days.

"We need this circuit breaker, this community pause," Marshall said. "We are going hard and we are going early. Time is of the essence and we must act swiftly and decisively."

The virus strain in the new cases was "highly contagious with short incubation period and limited symptoms. We have one chance, one chance, and will be throwing all our resources at it because we know the consequences of getting it wrong," he added.

Epidemiologist were unsure whether this was a genetically mutated virus strain.

"I haven't seen any official genetic data suggesting it's a new strain," said Professor Raina MacIntyre, head of the Biosecurity Program at the Kirby Institute, University of New South Wales.

The short incubation period "doesn't necessarily mean it's a new strain," he said. "Sometimes when you get a very, very high dose of virus you would become sick sooner. It could just be that."

The latest outbreak is linked to an Australian who arrived in the state capital Adelaide from overseas on November 2 and entered mandatory quarantine in a hotel. Hotel workers are believed to have contracted the virus after touching a contaminated surface.

South Australia state government did not immediately respond to questions from Reuters about the specific strain.