The CEO of Tusla has said the significant challenge for the Child and Family Agency, following last week's cyber attack, is that social workers do not have access to the background sensitive information contained in case files.
The Health Service Executive was forced to shut down all of its IT systems following the "significant" ransomware attack, which focused on accessing data stored on central servers.
Speaking on RTÉ's News at One, Bernard Gloster said Tusla has about 20,000 open cases including child protection and welfare and children in care, as well as many tens of thousands of other interactions, but all of that information is on the National Childcare Information System (NCCIS), and not available to them.
He said Tusla does not at this stage have any indication that the data is compromised other than being potentially locked by the attack, but will not know for sure until the system comes back as part of the HSE recovery process.
Mr Gloster said that over 90% of Tusla's connectivity is gone, and its databases and operating systems have been affected.
He said he is confident that the child protection work that needs to happen today is happening and the knowledge available to its local social workers is quite significant.
He said Tusla would usually receive about 1,500 referrals a week, and people can still make referrals about a child by ringing their local duty social work office and these numbers are available on the Tusla website.
Speaking on the same programme, the CEO of the Saolta University Health Care Group said all elective procedures and outpatient services have been cancelled for the coming week.
Tony Canavan said patients are being contacted directly if their scheduled appointment is going ahead.
"All other services and appointments are cancelled, unless you hear from us", he said.
Mr Canavan said there will be delays associated with radiology, but the situation is being "assessed every hour" and that systems will be back up and running "when we can ensure that it is safe".
He said the hospital group is able to access support from three private hospitals in the region "to help share the burden of patient care."
The Saolta University Health Care Group includes University Hospital Galway, Letterkenny University Hospital, Mayo University Hospital and Sligo University Hospital.
UL Hospital Group CEO Colette Cowan said clinics are running today but there will be significant cancellations for the rest of the week to ensure patient safety.
She said that access to diagnostics including x-ray and bloods is impacting the provision of services, including surgery appointments.
The hospitals will continue to deal with all time-critical patients in emergency care and will contact patients directly about attending appointments from tomorrow.
Ms Cowan said emergency departments, maternity emergency, injury and chemotherapy units are still operating despite the difficulties and the group has discussed outsourcing emergency care to the Bons Secours private hospital if required to do so for time-critical, emergency care.
Hospitals in the group are University Hospital Limerick, University Maternity Hospital Limerick,
Nenagh Hospital, Ennis Hospital, Croom Orthopaedic Hospital and St John's voluntary hospital.
Meanwhile, the director of St Luke's Radiation Oncology Network urged people who are feeling unwell to contact one of their three centres and said arrangements will be made for patients to be reviewed by medical teams.
Dr Claire Faul said the network, which is part of the Dublin/Midland Hospital Group, treats around 300 cancer patients a week.
She said they have been unable to use their machinery since Friday morning due to the ransomware attack and patients have not been able to receive treatment since then, but a "short break" in treatment has a "negligible" impact, "if at all", she added.
Dr Faul said the network has a contingency plan which has allowed for patients to be treated in the private sector since Friday and over the weekend, for emergency care.
She said the network's record system was isolated so patient lists and numbers were not affected and said she is "hopeful" that machinery will be back up and running this week.