Study finds no increase in cases of childhood hepatitis since the pandemic

A cluster of unexplained pediatric hepatitis cases in Alabama between October and February started a global investigation that sparked fears about the potentially devastating effects of adenovirus and COVID-19 on children’s livers.

But researchers at the US Centers for Disease Control and Prevention have now found that hospital visits for pediatric hepatitis and liver transplants did not increase between 2018 and 2022. Positive results for adenovirus, a primary suspect in the Alabama hepatitis cases, also remained steady, despite an increase in tests since March.

Cases of unexplained pediatric hepatitis, or liver infection, have always occurred and are rare, according to the CDC. Many cases of hepatitis in the US are caused by three viruses, hepatitis A, B and C.

Between October 2021 and February 2022, doctors at Children’s of Alabama noticed an unusual influx of hepatitis cases among children that weren’t caused by the three most common viruses. Doctors identified nine children with liver infections, including two who required transplants.

The CDC issued an alert notifying doctors about the cluster and asking them to report similar cases. The agency found 180 cases in 36 states that looked like the ones in Alabama. Countries outside the US also reported cases, including the United Kingdom, where more than 200 cases have been identified.

All nine Alabama patients tested positive for adenovirus and five tested positive for adenovirus 41. The virus has also been found in many of the international patients and became a focus for investigators. Adenoviruses usually cause respiratory or gastrointestinal illnesses, but have not been linked to hepatitis in healthy children. Some experts also believed prior infection with COVID-19 might play a role in the hepatitis cases.

To better understand recent pediatric cases, researchers from the CDC studied hospital admission data for liver infection and transplants.

“Data from four large administrative databases were analyzed to assess trends in pediatric hepatitis and percentage of stool specimens positive for adenovirus type 40/41,” the report found. “These data indicate that neither outcome has recently increased above pre–COVID-19 pandemic levels.”

A median of about 32 children between the ages of 0 and 11 were hospitalized each month with hepatitis. A median of four children younger than 18 received liver transplants each month according to the researchers.

The data on hepatitis and adenovirus are limited because doctors and other health care providers aren’t required to report that information to public health agencies. Researchers said the true baseline number of cases remains unknown. There’s also a lag in reporting hospitalizations which could affect the numbers from March 2022.

The report only looked at cases in the United States, not in other countries where cases have been found. Alabama officials have not reported any additional cases since February.