MILDURA testing of wastewater unexpectedly detected COVID-19 fragments this week.
The positive detection followed sampling at Mildura’s wastewater treatment plant, which covers one-third of the city, on Tuesday.
The Mildura plant had not had positive detections in 10 previous samples dating back to September 8, when the last unexpected detection of COVID-19 fragments was discovered.
This week’s finding was just the second time COVID-19 fragments had been found in Mildura’s wastewater in 12 months, despite frequent testing.
The treatment plant at Koorlong, which serves two-thirds of Mildura as well as the Irymple and Red Cliffs areas, also returned expected viral fragments on Tuesday.
It was the 13th time fragments had been found at the Koorlong plant since September last year and followed an unexpected detection in May this year.
Mildura has only one known active case and no known exposure sites.
The Department of Health and Human Services said the detection could be an undiscovered new case or cases or could be the result of one or more people in the area who had recovered from COVID-19 still shedding the virus.
The department said anyone who lived in, worked in or has visited the region should watch for the mildest of COVID-19 symptoms and get tested as soon as possible if they developed.
Wastewater testing at Dareton also returned a positive result for COVID-19 fragments.
The most recent result, from testing on Tuesday, followed earlier unexpected detections on September 16, 20, 21 and 23.
There has been no confirmed cases in the Wentworth local government area since the pandemic began.
The successive detections of Dareton wastewater fragments prompted health authorities to take the unusual step of urging residents to get tested, even if they did not have symptoms.
The Far West Local Health District (FWLHD) introduced voluntary surveillance COVID-19 testing in Dareton as part of an effort to increase the region’s testing rates.
Under the new measures, anyone in Dareton who does not have symptoms, and has not been identified as a contact, may be tested but will not need to self-isolate while awaiting their COVID-19 test results.
Anyone who has symptoms, or has been identified as a casual contact of someone with COVID-19, will still need to isolate until they receive a negative test result.
Close and household contacts need to isolate for 14 days regardless of their test results.
The FWLHD reported seven new cases of COVID-19 to 8pm Thursday, all of which were in Broken Hill and were household contacts.
