The man and woman in their 60s remain in a stable condition in isolation at the Royal Adelaide Hospital after tests confirmed the presence of the virus.

SA medical authorities said it was now known that one of the patients was showing symptoms while aboard China Southern Airlines flight CZ663.

It was initially thought that neither were showing symptoms of the flight from Guangzhou in southern China.

"Anybody who was on this flight is encouraged to contact the communicable disease branch of SA Health and discuss whether or not they have developed symptoms themselves," Chief Medical Officer Nicola Spurrier said on Monday.

"We will be trying to make contact with as many people on that flight as possible, particularly people who were situated close to these two cases."

It was also confirmed two people showing symptoms were taken from a domestic flight that arrived in Adelaide from interstate on Monday and would be tested for coronavirus.

Previously all samples gathered from people in Adelaide for testing were being sent to Melbourne, but SA Pathology has now set up a new testing facility at the Royal Adelaide Hospital.

It is already performing some tests and is expected to be fully operational by the end of the week.

SA Pathology clinical services director Tom Dodd said the new facility could be scaled up as necessary and would reduce the turnaround time on tests to about 24 hours.

Australian Associated Press