Unexplained hepatitis in children happened before pandemic, CDC study suggests

CDC investigators probing a rash of mysterious hepatitis illnesses in children across the country have one reassuring finding to report so far: cases are not occurring with any greater frequency now than before the COVID-19 pandemic.

The team of researchers began exploring a potential tie-in to COVID-19 and/or adenovirus after ruling out many of the usual culprits behind hepatitis. They reviewed 3 large medical databases and found that the number of weekly emergency department visits, monthly hospital admissions, and monthly liver transplants linked to unexplained and severe hepatitis were not significantly higher in late 2021 and early 2022 than during prepandemic years going back to 2017. They published their findings in the June 17, 2022, issue of CDC’s Morbidity and Mortality Weekly Report.

Another finding showed that, based on routine screening of pediatric stool samples, positive results for adenovirus types 40 and 41 also were not significantly greater in recent months.

The study is far from definitive, and more work is needed, said the researchers, noting that a slight upward trend in cases could go easily undetected since the diagnosis is so uncommon. It also is possible that clusters of cases both domestic and overseas simply reflect greater awareness of a problem that has existed all along.

“Ongoing assessment of trends, in addition to enhanced epidemiologic investigations, will help contextualize reported cases of acute hepatitis of unknown etiology in U.S. children,” the study authors wrote.