The HSE has identified 16 probable cases of children with hepatitis from unknown causes since March.
All the children involved are aged between 1 and 12, and all but one of them have been hospitalised.
Two children received a liver transplant and there has been one death associated with the disease.
Parents are advised to visit a GP if a child produces a grey stool, dark coloured urine or if it has yellowing eyes or skin.
