Patients Under Investigation

Children with Acute Hepatitis of Unknown Etiology

While rare, children can still have serious hepatitis, and we don’t always know the cause. That’s why investigators continue to look at possible causes and investigate.

Numbers of patients under investigation (PUI): 398

PUI does not mean this patient is a confirmed case. The states and CDC are looking broadly (including hepatitis cases of unknown origin in children under 10 years of age, since October, 2021), so this number may go up or down as CDC and states review medical charts and learn more.

States and Jurisdictions Reporting at Least One Patient Under Investigation (47)* as of September 6, 2023

*These may not be recent cases of hepatitis being reported.

To protect patient privacy, numbers for each state will not be released.

These data were posted on September 6, 2023 and reflect data from October 1, 2021. Reported PUIs are preliminary and subject to change as more data become available. Data will be updated monthly.

Patients Under Investigation: Children <10 years of age with elevated aspartate aminotransferase (AST) or alanine aminotransferase (ALT) (>500 U/L) who have an unknown etiology for their hepatitis (with or without any adenovirus testing results, independent of the results) since October 1, 2021.