In Queensland, waste water research has reported potential undiagnosed cases of COVID-19.
On Saturday, the state announced that no new coronavirus cases and four active cases were reported.
But there may be more diagnoses that are lurking.
“Samples taken at the Sandgate wastewater plant on (October) 12 and the Maroochydore and Wynnum wastewater plants on the 13th both returned positive results for virus fragments,” Deputy Premier Steven Miles said.
The plants are in suburban Brisbane and on the Sunshine Coast is Maroochydore.
“It could, of course, be someone who’s recently had the infection and then has gone to those places, so they’re not infectious but they’ve recovered, but they’re still shedding virus,” Chief Health Officer Jeannette Young said.
“But it could, of course, be a person that we’ve not picked up, that’s out there in the community.”
Health officials advise people to be tested if they feel unwell, and 4722 tests have been performed across Queensland in the past day or so.