South Australia's public health system has entered into what the SA Government has described as an historic emergency agreement with the private sector to help treat coronavirus patients.

Key points: The SA Government says the deal will free up beds for public patients across the state

The SA Government says the deal will free up beds for public patients across the state Premier Steven Marshall says travel over the upcoming Easter break is "completely and utterly off"

Premier Steven Marshall says travel over the upcoming Easter break is "completely and utterly off" Another 11 people, including a teenager, have tested positive to coronavirus, taking the SA total to 407

The Government said the deal with the operators of about 60 private hospitals and healthcare facilities across the state would make more beds available to public patients during the pandemic.

Premier Steven Marshall said the sectors had effectively "joined forces".

He said there were currently 1,700 beds in private hospitals, including 40 per cent of the state's intensive care capacity.

"For the first time in history, South Australia will mobilise the private hospital sector along with the public hospital sector," he said.

"We'll be working together, hand in hand, shoulder to shoulder."

Mr Marshall also announced an Easter travel ban, saying his biggest concern at the moment was complacency.

"As we see the number of new infections stabilise, I don't want anybody to think we can relax the restrictions," he said.

"This Easter, this school holidays, travel around this state is completely and utterly off. We do not want people heading out.

"I know this is very tough on many families … it's really important we follow this restriction. By doing so we will unequivocally save lives."

The hospital deal, which Mr Marshall said would be "in the order of tens of millions", is being supported with Federal Government funding.

"We have significant capacity," Calvary Care regional chief executive Sharon Kendall said.

"These are unprecedented times and it's really important that the public and private sectors stand side by side to deal with this crisis."

The number of COVID-19 cases in South Australia stands at 407 — an increase of 11 since yesterday.

That includes one who travelled on the Ruby Princess cruise liner, which now accounts for 85 cases in SA.

There are now 16 Adelaide Airport baggage handlers and nine of their close contacts who have been diagnosed with the coronavirus.

"We haven't seen the scale in growth in the number of cases that had been feared," Deputy Chief Public Health Officer Michael Cusack said.

"In the 11 [latest cases], the ages range from a person in their teens through to someone in their 70s.

"We've only just had the test result back from the person in their teens and the interviews are still taking places.

"If there are any school links, we will inform you."

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Bus passenger made coronavirus threat

Earlier today, the State Opposition said it would introduce new legislation to better protect frontline workers from coronavirus-related assaults or threats.

Under the legislation, any person who assaulted a worker and either had COVID-19 or claimed to have it would face up to 10 years in jail.

Frontline workers include healthcare staff, emergency service personnel, retail and public transport workers.

Opposition Leader Peter Malinauskas said police had to remove a passenger from an Adelaide Metro bus this week, after the man said he had coronavirus.

"This should be subject to criminal sanctions," he said.

"These are unacceptable actions, particularly if they're against frontline workers who are simply trying to protect our community. They're looking after us. It's really important we look after them.

"There is no way we can tolerate anyone using the threat of COVID-19."