The number of new COVID-19 infections in NSW has dropped slightly to 5612, as the mandate on wearing masks indoors resumes.

The cases were diagnosed from more than 164,000 tests in the 24 hours to 8pm on Thursday and represent a decrease of 103 from Wednesday.

One death was also reported.

The number of people in hospital has climbed to 382, up 35, with 53 in intensive care, an increase of eight.

NSW is battling by far its most widespread outbreak, spurred on by the highly transmissible Omicron variant, forcing NSW to scale back contact tracing efforts.

Just over one in two – 54 per cent – of people who test positive were fully interviewed by health bureaucrats within a day last week.

The week prior, that figure stood at 94 per cent.

To help NSW Health direct resources to the most vulnerable or high risk cases, people who test positive will get a text message asking them to fill out an online questionnaire.

About four in five people fill it out, said NSW Chief Health Officer Kerry Chant on Thursday.

Those who are only contacted by text are asked to let their contacts know about their diagnosis, a task which used to be performed by bureaucrats.

Only those who work at or have visited a high-risk setting like a disability group home, Aboriginal community or jail will get a phone call from NSW Health. 

The spike has also forced the government to reintroduce some restrictions the were only wound back under two weeks ago.

Premier Dominic Perrottet reinstated an indoor mask mandate from Friday morning.

From December 27, hospitality venues will return to the one person per two-square metre rule and QR codes will again be compulsory in all settings.

The restrictions will last at least a month.

AAP

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