A potential case of COVID-19 in a teenager who recently travelled from South Australia to New South Wales has been ruled out, with his initial test result deemed a "false positive" by health authorities.
SA Health sent close contacts into quarantine as they awaited further test results from NSW Health, but said the group of five had now been allowed out.
SA Chief Public Health Officer Nicola Spurrier said the young man left South Australia on Thursday, and that SA authorities were informed last Friday about the potential case after the man had taken a COVID-19 test in NSW.
"It was very weakly positive. When we do our PCR testing, we look at two different parts of the gene and there was only one part of that positive, so it was a very weak positive," Professor Spurrier said.
"That young person went on to have two subsequent swabs which were negative."
Authorities were investigating any "overlap" in the man's movements with six interstate truck drivers who recently tested positive, but earlier said there was no evidence he had attended any of the exposure sites linked to those cases, which included two hotels.
"As everybody knows, we've had truck drivers who have been positive in our state," Professor Spurrier said.
The man has family in both South Australia and New South Wales, and Professor Spurrier earlier said blood tests were expected to shed further light on the man's case.
She said the five close contacts had all been tested and returned negative results.
SA Health confirmed suspicions the young man's test was a "false positive".
"NSW Health has reviewed results regarding a teenager who travelled from South Australia to New South Wales last week and determined it is a false positive," SA Health said in a statement.
There were no new COVID-19 cases reported in SA on Tuesday, and authorities announced an easing of social distancing measures.
South Australians will be able to stand up and drink in beer gardens and other outdoor venues from Thursday, with the state's authorities also set to ease COVID-19 testing requirements for travellers from south-east Queensland.
