Mystery COVID-19 infection one of four new cases confirmed in South Australia
Health authorities are investigating the unlinked case, but said the person spent time in the Port Noarlunga region.
People from the area are being encouraged by SA Health to get tested if they display COVID-19 symptoms, and isolate immediately.
Three of the cases are men aged between 20 and 70, while the fourth is a woman in her 30s.
The daily total of four new infections is a considerable drop from Thursday, when 18 cases were recorded.
Some companies have started cancelling end of year events.
Dr Chris Moy from the Australian Medical Association said the new outbreak is likely to cause hesitancy for some people to go out.
"I think everybody's feeling that, I suppose we haven't had the same reality as the eastern states," Dr Moy said.
Among the venues cancelling events is Ayers House.
It cancelled a large-scale event that was supposed to happen on Saturday night.
Ayers House director Richard McLeod said he did not think the outbreak could be contained now.
"I just think we have to run with it," Mr McLeod said.
"I just hope the government doesn't shut us down. I think they government should stand by what they said, they should keep us open, this is their decision.