SPRINGFIELD, Ill. — Illinois health officials have issued an update on a severe hepatitis warning after announcing three suspected cases in children last month.

The Illinois Department of Public Health (IDPH) announced Wednesday that nine children, all under the age of 10, are suspected of severe hepatitis, up from the three reported in April.

IDPH says the cases date back to January, with the most recent in May.

State health officials say they have been working with the CDC to identify additional U.S. cases and learn the cause.

Symptoms of hepatitis, or inflammation of the liver, include fever, fatigue, loss of appetite, nausea, vomiting, abdominal pain, dark urine, light-colored stools, joint pain, and jaundice and can be caused by viruses. These cases appear to have an association with adenovirus 41. 

Symptoms of adenovirus type 41 typically include diarrhea, vomiting and fever, and are often accompanied by respiratory symptoms.

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