About 1,200 children are being urged to undergo testing for infectious diseases after a Melbourne childcare worker was charged with a string of offences including child rape.

Joshua Dale Brown was arrested in May and faces 70 charges, with police alleging he abused eight children – including a five-month-old – between April 2022 and January 2023.

The 26-year-old has worked at 20 childcare centres since 2017, prompting local health authorities to notify parents of any children who may have been in his care, recommending many be tested as a “precaution”.

Joshua Brown is yet to enter a plea to the charges and has been remanded in custody. He is due to appear at Melbourne Magistrates Court in September.

The eight children who police allege were harmed were all under the age of two and attended one childcare centre in a suburb of Melbourne.

Joshua Brown is accused of child rape and sexual assault offences, as well as producing and transmitting child abuse material.

Detectives are also investigating alleged offences by him at a childcare centre in Essendon, another Melbourne suburb, “as a priority”.

At a press conference, authorities said he had a valid working with children check and was employed as a childcare worker when he was arrested.

Joshua Brown was not known to them before the investigation, they said, adding that they believed he acted alone and that the alleged offending only happened in Victoria.

Revealing his identity was an “unusual decision”, Victoria Police’s Janet Stevenson said, but this is a “unique” case.

“It’s very important to ensure that every parent out there that has a child in childcare knows who he is and where he worked,” she said.

Chief Health Officer Christian McGrath would not say if the accused man had tested positive to sexually transmitted infections, but said the manner of the alleged offending meant some children may be asked to undergo screening for infectious diseases.

About 2,600 families had been contacted, with 1,200 children recommended for testing, he said, adding that the infections that the children may have been exposed to can be treated with antibiotics.

Victorian Premier Jacinta Allan said she was “sickened” by the allegations.

“My heart breaks for the families who are living every parent’s worst nightmare,” she said.

Families across Victoria will be “angry and frightened” by the case, Allan said, adding that a dedicated website has been set up for those impacted.