People queue for a Covid-19 test in Adelaide
(Picture: Getty Images)South Australia has gone on high alert after its first coronavirus outbreak since April.
An outbreak of the coronavirus in the city of Adelaide has grown to 18 cases and prompted the closure of two schools and a fast-food restaurant.
Health authorities say they believe a worker at a hotel where people arriving from abroad are being quarantined caught the virus and then infected other family members.
Up to 13 infections are linked to that hotel worker alone, the BBC reported.
Authorities are scrambling to contain the outbreak and have opened a pop-up testing station and are tracing contacts of those infected.
Meanwhile, authorities in the state of Victoria notched a 17th straight day without any new cases on Monday, after they battled a major outbreak in Melbourne earlier this year.
A quarantine hotel breach also caused an outbreak in Melbourne
Getty ImagesAustralia had seen cases near zero after beating back the second wave in Victoria. Its outbreak also began from a quarantine hotel breach.
South Australia's chief health officer Nicola Spurrier said that quarnatine hotels posed the highest risk.
"It's obvious that the highest risk in Australia right now is this risk of (virus) importation in our quarantine hotels", she said.
State Premier Steven Marshall said that no effort will be spared in the battle against the virus.
"We are facing our biggest test to date", he said.
"We are working around the clock to stay ahead of this cluster - no effort will be spared."
