Across the weekend there were seven cases reported in overseas travellers, all in hotel quarantine.

The new locally acquired case of the virus is a household contact of a confirmed case in Moss Vale. Contact tracing and investigation into the source of the infection continues.

Meantime, an alert has been issued for Big W customers in the Southern Highlands after a person with COVID-19 visited their Mittagong store on October 31.

The chain-store giant issued a statement, explaining the store had since undergone a "deep clean".

"Any customers who shopped in our Mittagong store since Saturday, October 31 and feel unwell in the two weeks that follow should make contact with the Department of Health and Human Services for advice," the statement said.

The customer visited the store on Saturday October 31, between 12pm and 12:10pm.

NSW Health said due to these and other recent cases, in line with previous advice the call for testing continues to apply particularly to people in South Western Sydney, including in and around the communities of Leppington, Hoxton Park and Prestons; and to people in the Southern Highlands region, including the communities in and around Moss Vale, Mittagong and Bowral.

Extra testing capacity has been made available in these regions.

To help stop the spread of COVID-19:

- If you are unwell, get tested and isolate right away - don't delay.

- Wash your hands regularly. Take hand sanitiser with you when you go out.

- Keep your distance. Leave 1.5 metres between yourself and others.

- Wear a mask when using public transport, rideshares and taxis, and in shops, places of worship and other places where you can't physically distance. When taking taxis or rideshares, commuters should also sit in the back.

There are more than 300 COVID-19 testing locations across NSW. To find your nearest clinic visit https://www.nsw.gov.au/.../how-to-protect.../clinics or contact your GP. Most people receive their test results within 24 hours.