The Minnesota Department of Health (MDH) said it’s investigating several severe cases of hepatitis among children, and has reported the cases to the Centers for Disease Control and Prevention. The CDC continues to investigate cases of the sudden liver disease in nearly 200 children in several countries.

M Health Fairview reported two cases to MDH, which involve an infant and a two-year-old. Hospital officials say one of the patients was treated several months ago, which included a liver transplant.

The illness is being called hepatitis of unknown origin. The cases have no known connection, although a link with a virus that can cause colds is being investigated.