They were among 78 new local cases of the virus recorded in NSW in the 24 hours to 8pm Monday.

The new case in the Wollongong area is linked to the two cases reported on Monday, and all three are isolating at home.

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"Case investigations are underway, however it is believed there are links to employment in the Sydney area," an Illawarra Shoalhaven Local Health District spokesperson said.

NSW Health data shows that all three people reside within the 2530 postcode, which includes Dapto, Horsley and Koonawarra.

The 78 new cases in NSW were detected from 62,860 tests.

Twenty-one cases were in the community for their entire infectious period, while eight cases were in isolation for part of their infectious period.

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The isolation status of 12 cases remains under investigation.

Premier Gladys Berejiklian said the number of people who were out in the community while infectious needed to come down.

"It's always pleasing when you see a drop in those numbers, but we still had about 27 people infectious in the community in those numbers," Ms Berejiklian said.

But she said the efforts of the community were making a difference.

"That 78 number would have been much, much higher had people not been doing the right thing," Ms Berejiklian said.

There are 95 COVID-19 cases in hospital, with 27 people in intensive care, 11 of whom are ventilated.

A total of 1418 people have now been diagnosed with the virus since the first case of the current outbreak was reported on June 16.

Wollongong, Shellharbour and the rest of Greater Sydney are now in the fourth week of lockdown, which is currently scheduled to end on July 30 - although an extension has not been ruled out.

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Construction is also on pause until that time, and builders, unions and construction companies have formed a united front to lobby the government to allow some workers back on sites before the end of the month.

Ms Berejiklian defended the construction shutdown as necessary but said the government was working with the sector on safe ways to open up again on July 31.

She flagged the industry would have extra safety measures including on-site COVID testing.

"It was important for us to take a pause so that the industry can resume and continue safely and indefinitely," she said.

- With AAP

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