Residents in suburbs including Riverstone, Marsden Park, Schofields and Vineyard have been urged to get tested if they have even the mildest COVID-19 symptoms, after traces of the virus were detected at a sewage treatment plant in Riverstone.
The call by NSW Health follows the finding by the state's sewage surveillance team from samples taken on Sunday, November 29.
Other residents on alert are those in Shanes Park, Quakers Hill, Oakville, Box Hill, The Ponds, Rouse Hill, Nelson and Colebee.
"Detection of the virus in sewage samples could reflect the presence of known cases of COVID-19 diagnosed in recent weeks in the area served by this sewage treatment plant," NSW Health said via a statement.
"However, NSW Health is concerned there could be other active cases in the local community in people who have not been tested and who might incorrectly assume their symptoms are just a cold.
"Particularly in light of the easing of restrictions on gatherings announced earlier today [Wednesday, December 2], it is important that people in these areas be aware of any symptoms of illness, and immediately isolate and get tested should even the mildest of symptoms appear."
NSW Health reminded that the following "cold-like symptoms" would warrant getting checked: a runny nose or scratchy throat, cough, tiredness, or fever.
"After testing, you must remain in isolation until a negative result is received," the statement continued. "The only way to find new cases and prevent further transmission is to increase testing. There are more than 300 COVID-19 testing locations across NSW. To find your nearest clinic visit COVID-19 testing clinics or contact your GP.
"Sewage testing for genetic material of SARS-CoV-2, the virus that causes COVID-19, started in July, adding another tool in the fight against the global pandemic.
"There is no evidence COVID-19 is transmitted via wastewater systems."
