Coronavirus fragments have been found in South Coast and Northern Beaches sewage systems, health authorities say, and that could be a sign there are undetected cases in the community.
NSW Health said in a statement on Saturday that virus fragments had been detected in sewage systems at Merimbula on the South Coast and Allambie Heights in the Northern Beaches.
The authority said the Allambie Heights sewage system serviced about 83,400 people in the Northern Head catchment.
The catchment included the suburbs of Allambie Heights, Balgowlah, Curl Curl, North Curl Curl, North Manly, Freshwater, Collaroy, Collaroy Plateau, Narrabeen, Wheeler Heights, Oxford Falls, Dee Why, Cromer, Beacon Hill, Narraweena, Brookvale, and Frenchs Forest.
The Merimbula sewage system serviced about 15,000 people on the South Coast.
NSW Health said the fragments could signal there were people in the area who had recently recovered from COVID-19, as they could continue to shed the virus for several weeks after their recovery.
But, it also warned the fragments could mean there were undetected cases in the community.
"[NSW Health] asks people in these areas to be alert for any cold-like symptoms that could signal COVID-19, including sore throat, runny nose, cough, fever or headache," the authority said.
"If symptoms appear, please isolate and get tested immediately, and remain isolated until a negative result is received."
NSW Health urged everyone in the state to scan QR codes when they checked into venues, practise good hand hygiene, and stay home after they got tested for COVID-19 if they were feeling unwell.
