NSW records 20,087 new infections amid warning over Omicron BA.2 sub-variant

New South Wales has recorded a further 20,087 COVID-19 cases, as health experts urge residents to adhere to public health measures as the Omicron BA.2 sub-variant spreads.

While today's case numbers are down from Wednesday's 30,402 infections, NSW Health said a "data processing issue" from Sunday and Monday accounted for roughly 10,000 cases yesterday.

Five more lives have been lost in the state and 34 patients remain in ICU.

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Seven days ago 16,288 cases were reported in NSW, and health experts have warned the BA.2 sub-variant could cause infections to double in four to six weeks.

Infections have also risen in Victoria, where 9752 new cases were clocked.

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"It is probably just as severe and we have had more deaths this year in 2022 than in the whole of the previous two years," infectious diseases expert Professor Robert Booy told Today.

"We have to pay attention. We have to do clever things."

He said a return to lockdown would not be necessary, but people should consider a return to mask-wearing indoors, working from home if possible, and avoiding crowds.

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"I don't think we need to have lockdowns," he said.

"I think what we have got in place can be built upon, sensibly and simply. Wearing masks indoors, especially where it is crowded and poorly ventilated. Watching for crowds. Wearing masks on public transport.

"Working from home if you could do it, just as well as working in the office."

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