NSW tracers rush to track Kiwi travellers

New South Wales contract tracers are racing to reach 455 travellers from New Zealand after a positive case was confirmed in Auckland.

Those who arrived in NSW from New Zealand since November 5 have been sent a message with NSW Health advice and are being contacted and alerted about a number of venues of concern in Auckland.

NSW Health said in a statement no passengers arriving in Sydney from New Zealand on Friday evening reported having visited the locations and none had symptoms.

"Airlines will ascertain if passengers have attended these venues before they leave New Zealand and if they have, they will be not allowed to travel," the department said.

All arrivals from New Zealand will be asked to monitor for even the mildest of symptoms and get tested and isolate if they appear unwell, NSW Health said.

NSW has now gone a week without a locally-transmitted virus case but health authorities are still urging the community to keep getting tested.

Positive cases continue to be detected among overseas travellers in hotel quarantine, with the state recording four on Saturday.

Some 17,184 people were tested for the virus between Friday and Saturday.

NSW Health's Dr Jeremy McAnulty thanked the community for the increase in testing numbers but urged people in the Rouse Hill, Bowral and Moss Vale areas to get tested after virus traces were found in sewage.

"Anyone in these areas is urged to get tested immediately if they have any symptoms at all that could signal COVID-19," he said on Friday.

While detection in sewage samples could reflect the presence of older cases in those areas, NSW Health fears there could be other active cases in the local community.

NSW will reopen its border with Victoria on November 23. The southern state has recorded more than two weeks of consecutive zero-transmission days.

No quarantine will be required upon arrival or departure from the state.