COVID-19 has been found in the wastewater of 31 Melbourne suburbs despite no locally acquired cases being reported in almost two months.
On Tuesday (local time) Victoria's health department revealed coronavirus fragments were found in the wastewater of suburbs in the north and east of the city.
The fragments were found in samples taken from sewer catchments in Moonee Ponds and Ringwood.
The affected suburbs include Ascot Vale, Brunswick, Brunswick West, Coburg, Essendon, Essendon Fields, Flemington, Kensington, Moonee Ponds, North Melbourne, Parkville, Pascoe Vale, Pascoe Vale South, Strathmore and Travancore.
The eastern suburbs include Bayswater, Bayswater North, Boronia, Croydon, Croydon North, Croydon South, Heathmont, Kilsyth, Kilsyth South, Montrose, Ringwood, Ringwood East, Sassafras, The Basin, Tremont and Wantirna.
Residents or people who have visited the areas are being urged to monitor for symptoms and get tested if they develop any.
COVID-19 symptoms include fever, coughing, sore throat, shortness of breath, runny or blocked nose, headache, muscle or joint pains, nausea, diarrhoea, vomiting, loss of sense of smell, altered sense of taste, loss of appetite and fatigue.
On Wednesday, Victoria's chief health officer Brett Sutton told The Australian the wastewater fragments could be from a positive case in the early infectious stage.
"While it is possible that these detections are due to a visitor or visitors to these areas who are not infectious, a cautious approach is being taken."
On Wednesday, Victoria recorded no new cases. It hasn't had a locally acquired case in 53 days.
It follows a trans-Tasman quarantine travel bubble between Australia and New Zealand opening on April 19. The bubble allows New Zealanders and Australians to fly between the countries without entering managed isolation.