One of South Australia’s positive COVID-19 cases from yesterday has been revised as a false positive.

The case, in a woman in her 20s, had been the cause of some concern with health authorities unable trace the virus to a known cause.

Fears of community transmission had been raised, however, the state’s chief public health officer Dr Nicola Spurrier says that health authorities are now absolutely sure that she is negative.

SA Health officials now turn their attention primarily to a cluster patient in her 20s who visited several businesses and two Adelaide schools while infectious.

Yesterday, health alerts were issued for people who visited three businesses in Adelaide’s inner northern suburbs over the past week.

The revision of the case to a false positive means that South Australia has now recorded a total of 457 cases of the virus.

14 of those cases have been confirmed in SA over the past fortnight.