After some final questions to Victoria Police the press conference has ended. 

We'll leave our live coverage there. 

Minister for Children Lizzie Blandthorn is now being asked about why there was a lag between the government being briefed on the allegations and launching its own investigation.

She says the government did not want to interfere with the police investigation.

She reiterated that the investigation was being managed by Victoria's early childhood regulator and will begin immediately.

She says the investigation will determine whether there was anything that could be done differently.

CHO Christian McGrath is now taking questions and says he will not be detailing the specifics of the infectious disease.

He says this is sensitive health information for families.

Earlier Dr McGrath stressed that the infection was one that could be treated with antibiotics. 

He says he can't elaborate much on how authorities reached the 1,200 number, but says the approach was cautious and that authorities are very confident that those who have not been identified will not need the screening.

He says families who are not in the 1,200 but may be worried should call the advice line.

He says he anticipates the testing of the 1,200 children may take "days to weeks".

Premier Jacinta Allan is asked how parents can be confident about the safety of their children in childcare.

She stresses that the accused is one alleged offender and did have a working with children check, but acknowledges that parents across the state will be asking that question, and that "parents do deserve answers".

"The safety of our kids when we place them in the care of professional centres has to be of paramount importance," she says.

Commander Stevenson is answering more questions.

In response, she reiterates that the accused was not known to police.

She says "basically" all the 70 charges relate to the eight alleged victims.

She also says the alleged victims were aged between five months and two years old.

Commander Janet Stevenson is now taking questions.

In response to a question about why there was a lag between the alleged offences being indentified and alleged victims being noticed, she says it took police some time to identify the alleged victims.

Ms Allan says that as well as families directly impacted by the allegations, the news would impact families across Victoria and people in the childcare industry.

She says the early childhood regulator will be investigating the conduct of the early education providers for which the alleged offender has worked.

"The safety of our children is our number one priority," she says.

Premier Jacinta Allan is now speaking. 

She says that as a parent, her heart breaks for families who may be impacted.

She says every health and mental health support will be provided to these families.

Dr McGrath says a dedicated advice and support hotline for affected families has been set up.

The hotline is 1800 791 241, and it is open 7 days a week from 8am to 9pm on weekdays and 8am to 5pm on weekends.

Dr McGrath says that when families call this number, they will be given health advice, including whether testing is recommended for their children. 

Dr McGrath says 2,600 families who had attended the relevant childcare centres while the accused was working there have been contacted.

He says they are recommending some children undergo testing for infectious diseases due to a potential exposure risk.

He says authorities believe this is a "low" risk, and understand this is distressing. 

About 1,200 children have been recommended to undergo testing.

He says the infections children have been potentially exposed to can be treated with antibiotics.