Key points from Victorian Premier Daniel Andrews' press conference on Friday - ABC News

Friday's case numbers rose by almost 100 over Thursday's and 14 more people have died, including a man in his 20s — Australia's youngest death from COVID-19.

Victorian Premier Daniel Andrews has just given his latest press conference. Here are the key points.

The key case numbers:

Victoria recorded 372 new cases overnight. That's up from 278 yesterday.
Fourteen people have died, including a man in his 20s. It's Australia's youngest death from COVID-19.
The other deaths are three women and two men in their 80s, and four women and four men in their 90s.
There are 659 people in hospital. Of those, 41 are in intensive care, with 26 people on ventilators.
There are a total of 3,119 mystery cases, that's 51 more than yesterday.
There are 7,842 active cases across the state. Of those, 1,188 are in healthcare workers, and 2,034 are in aged care settings.
In regional areas, there are 492 active cases, down from 512 previously
There are 167 cases in Geelong, 56 in Bendigo and 25 in Ballarat

One in five cases from an unknown source

Victoria's Chief Health Officer Brett Sutton said that in metropolitan Melbourne, 20 per cent of cases are a mystery: we don't know how the COVID-19-positive person became infected.

In regional areas, the unknown transmission is at 13 per cent.

"But the 13 per cent is still of concern because it does represent those mystery cases that might've been picked up locally in those local government areas," Professor Sutton said.

He said the number of mystery cases had plateaued in the past week or so, and defended the state's contact tracing efforts.

"We are still contact-tracing every single case that comes in," he said.

"When you've got 300, 400 cases a day, that stretches any system."

He added the average time between someone getting tested and notified of their test result was 1.6 days on average, but there were people waiting five days to hear their diagnosis.

Young people make up a quarter of mystery cases

People in their 20s are over-represented in the mystery cases, Professor Sutton said.

A graph showing 27 per cent of mystery cases are in people aged 20-29. — Age group data shows people in their 20s dominate the number of mystery cases in Victoria.(Supplied)

More than a quarter of mystery cases are in 20-29-year-olds, representing the majority.

Professor Sutton said that was largely due to their mobility — they are more likely to carry out essential activities for their household and be engaged in the workforce.

"There are more opportunities for the age group to become infected and to be exposed to transmission," he said.

Premier Andrews was asked if the higher proportion of youth in mystery infections was because of rule-breaking.

He said it was important not to make broad statements about any age group and it was probably due to their level of movement.

"They are the people doing the shopping, they are the people who are working in permitted industries and are going out. They're people who are out and about for lawful reasons, as much as they are out and about breaking the rules," he said.

"In a general sense, a high percentage of Victorians are doing the right thing and I'm grateful to them."

'We've seen the peak'

Professor Sutton said Melbourne appeared to have "turned the corner" with masks and stage 3 restrictions, but stage 4 measures are still yet to be played out in the numbers.

"It's going in the right direction. I'm very confident we've seen the peak. But it's got to come down quickly," he said.

Brett Sutton stands in front of a purple and black background. — Victorian Chief Health Officer Brett Sutton said he's confident Victoria has passed the peak in its second wave.(AAP: James Ross)

"It would be terrific if it's true. I'm very confident it's true. But we always watch the numbers every day.

"Today's number is bigger than yesterday, and we don't know what tomorrow will necessarily bring.

"But the trend is definitely downwards. The five-day trend, the seven-day trend indicates that the peak was probably four or five days ago."

He urged Victorians to "keep at it".

The Premier said he wasn't going to make predictions.

"I'm not trained to do that. I want to see the data, I want to see the numbers continue to fall," he said.

He said it was important to do the job properly to ensure there wouldn't be a third or fourth wave, and said there would be "inevitable" outbreaks in the future.

Virus needs to be 'completely snuffed out'

Professor Sutton added we cannot conceive of opening up with 200 cases a day or even 100 cases a day.

"We really need to drive numbers down to the lowest possible level, including zero, to give us the greatest confidence that we can ease restrictions and not see an upsurge that would have us heading back to restrictions again," Professor Sutton said.

"We have to get to a point where it's entirely manageable, if not completely snuffed out."

He was asked if it was an "automatic rule" that anyone who got tested had to self-isolate.

"Anyone symptomatic who gets a test absolutely needs to self-isolate," he said, but asymptomatic individuals do not have to — unless they are a close contact, who needs to quarantine for 14 days.

"If we are a close contact, then we are always self-isolating," he said.

Who is patient zero?

There are questions swirling about who is "patient zero" after The Age revealed the first person to contract coronavirus at the Rydges Hotel was not a private security guard but a night manager at the hotel.

The sign outside the Rydges on Swanston Hotel. — Rydges on Swanston was one of two hotels used to house returned travellers for quarantine during the coronavirus pandemic in Victoria.(AAP: Scott Barbour)

Mr Andrews was asked if "patient zero" was a security guard or hotel employee.

He said that level of detail would be determined by former judge Jennifer Coate and her inquiry.

"I don't have any advice about who that person might be," he said.

"I think that whole notion that, necessarily, we could have, to the degree of certainty, clarity, about one particular person, I don't know that the science would ever lead you to that. It could, but it may not."

Professor Sutton was asked if he knew and said he wasn't able to provide "potentially identifying details".