NSW announced 11 new Covid-19 cases on Friday – seven from overseas travellers and four acquired locally.
Two of the local infections, a woman in her 50s and a teenage boy who live together, are linked to the Berala cluster.
Another is a child who is a close contact of a previously recorded case in Croydon. The Croydon cluster now totals 11.
The fourth locally acquired case is a man in his 40s from the northern zone of Sydney’s Northern Beaches who NSW Health officials announced on Thursday morning.
It is believed he is linked to the Avalon cluster but health officials are still searching for the confirmed source.
Fragments of the coronavirus have been detected in a sewage treatment plant at Ulladulla for the first time.
This catchment serves a population 32,000 people and takes sewage from Narrawallee, Milton, Mollymook Beach, Ulladulla, Kings Point, Burrill Lake, Dolphin Point, Lake Tabourie.
“There have been no recent locally acquired cases or returned travellers who tested positive from this area,” NSW Health said.
“This could mean there are undetected cases of Covid in the community or someone with the virus visited the area.”
Everyone in that area should monitor for symptoms, and if they appear get tested and isolate immediately.
Northern Beaches northern zone lockdown to end
NSW Health Minister Brad Hazzard said the northern zone of the Northern Beaches will come out of lockdown at 12.01am on Sunday but said NSW Health did have reservations given the new case in that area.
The suburbs north of Narrabeen Bridge have been under stay-at-home orders since before Christmas.
“The gentleman who returned to the positive case yesterday, had previously shown negative results,” he said.
“It is concerning, and there is no clarity here, perhaps he had a second infection of the virus, it is possible.
“It is really the unknown that is worrying.”
Mr Hazzard said the man’s infection “could be an indicator of unknown chain or chains of transmission still circulating in the far end of the Northern Beaches.”
NSW on Thursday reported no locally acquired cases of Covid-19 in the 24-hour period to Wednesday night. Six cases were confirmed in returned travellers.
Alerts remain in place for a supermarket and discount chemist in Sydney's Avalon area.
They apply to anyone who shopped at Woolworths in Avalon at certain times between January 2 and January 6 and was at Chemist Warehouse for 15 minutes to 1.15pm in Avalon on January 3.
"Anyone who attended the following venues at the times listed must immediately get tested and self-isolate until you receive a negative result," NSW Health said.
Across the border, Greater Brisbane will enter a hard lockdown from 6pm on Friday after a cleaner at a quarantine hotel was diagnosed with the highly contagious UK strain of COVID-19.
Deputy Premier John Barilaro urged anyone from the lockdown areas of Brisbane, Logan, Ipswich, Moreton, and Badlands who are travelling to NSW to immediately isolate for two weeks.
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