Hunter New England Health said on Monday afternoon that a man in his 20s and a man in his 60s had contracted the virus but were doing well in home isolation.

A woman in her 60s was infected and was doing well but had been admitted to John Hunter Hospital as a precaution.

The man in his 20s is the source of the infection for a woman in her 60s identified on Saturday as having the disease and the man in his 60s announced on Monday.

HNEH has identified close contacts of the new cases and asked them to self-isolate for 14 days.

The male in his 20s works at Pokolbin's Oakvale winery and was likely exposed through interaction with an international tour group.

As a precaution, anyone who visited Oakvale from March 4 to 13 should be alert for fever or respiratory symptoms.

If they develop any of these symptoms, they should contact their GP or present to an emergency department.

"As a precaution, I'd like to point out that anyone who visited Oakvale winery at Pokolbin between the fourth of March and the 13th of March should be alert for fever or respiratory symptoms for 14 days after their visit," Mr Hazzard said at a media conference on Monday.

He said people did not have to avoid the Broke Road winery.

"I stress, though, that at Oakvale wines there was an issue. I'm stressing that each of these once the risk has passed there is no further risk," he said.

The woman in her 60s who was confirmed on Monday has not travelled internationally and the source of her infection is unknown.

She is in a stable condition and has been admitted to John Hunter Hospital for monitoring.

HNEH public health physician Dr David Durrheim said there was no reason for people to avoid the hospital.

"All the necessary precautions have been taken to prevent the spread of infection while the patient is in our care," he said.

"We ask everyone in Hunter New England to play a part in containing the spread of COVID-19 by washing your hands often, covering coughs and sneezes and staying home if you're unwell.

"Visit the NSW Health website for more advice."

The number of cases in NSW now stands at 171 after 37 new cases in the 24 hours to 11am on Monday.

It is the biggest daily jump in cases since the outbreak began.

Two more people have died from the illness in NSW and the number of cases nationally stood at 298 at 1pm.

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