South Australia expects the worst of the COVID-19 pandemic to hit late April or early May, though Premier Steven Marshall says the modelling is changing constantly.

SA Health today revealed a sharp jump in confirmed cases in South Australia, with an additional 17 bringing the total number to 67.

It came as a party of 18 US tourists was quarantined in the Barossa Valley after 10 members of the group returned positive COVID-19 tests after spending the past few days in self-isolation.

Chief public health officer Dr Nicola Spurrier told reporters there was “absolutely no need for people in the Barossa to panic”, saying her team was working through the process of interviewing the group and ascertaining where they had been in SA.

Marshall today said work to put the extra beds in place will start on Monday but it’s hoped the extra capacity is never needed if other measures are successful in reducing the extent of the outbreak across SA.

“We need to do two critical things. One is to slow the spread of this disease and to reduce the peak, pushing it as far into the future as possible,” Marshall said on Saturday.

“The second is to increase the hospital capacity in South Australia.”

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The premier conceded that while the government and other authorities were taking the virus seriously, there had been a mixed response across the wider community.

“There are still people who say that if I get this (virus) it’s going to be like a mild cough,” he said.

“And they’re right for a large part of the population.

“Eight out of 10 people that contract the coronavirus will have very mild symptoms.

“But they’re not the cohort that we’re concerned about. We’re concerned about the other 20 per cent.”

Marshall said modelling suggested about 14 per cent would require some form of medical intervention and six per cent would require intensive care and ventilation.

“We can’t be too prepared for this event. I hope we never need to activate these beds but we need to be ahead of the curve,” he said.

Also on Saturday, the SA Opposition said strict new protections were needed to protect students if schools were to stay open.

Opposition Leader Peter Malinauskas said that should include daily temperature checks for students and staff, hand sanitiser in every classroom and staggered recess and lunch breaks.

“This will not only protect staff and students, but the wider community as well,” Malinauskas said.

So far South Australia has recorded 50 coronavirus cases though that number is expected to increase when an update is provided on Saturday afternoon.

– AAP