296 children had hepatitis of unknown etiology by June 15, 2022

As of June 15, 2022, 296 patients met the criteria in the U.S. Centers for Disease Control and Prevention health advisory for children aged <10 years with onset of hepatitis of unknown etiology on or after Oct. 1, 2021, according to research published in the June 24 early-release issue of the U.S. Centers for Disease Control and Prevention Morbidity and Mortality Weekly Report.

Noting that the CDC issued a health advisory encouraging U.S. clinicians to report all patients aged <10 years with hepatitis of unknown etiology to public health authorities, Jordan Cates, Ph.D., from the CDC in Atlanta, and colleagues abstracted medical charts and interviewed patient caregivers for patients meeting the criteria in the health advisory (patients under investigation [PUI]).

A total of 296 PUIs with hepatitis onset on or after Oct. 1, 2021, were reported at 42 U.S. jurisdictions as of June 15, 2022 (median age, 2 years, 2 months). The researchers found that 89.9 percent of PUIs were hospitalized, and 6.1 and 3.7 percent required a transplant and died, respectively. In 44.6 percent of 224 patients, adenovirus was detected in a respiratory, blood, or stool specimen. In 10 of 98 and 32 of 123 patients (10.2 and 26.0 percent, respectively), current or past infection with severe acute respiratory syndrome coronavirus 2 was reported. There were no common exposures identified (e.g., travel, food, or toxicants).

"Parents and caregivers should contact their child's health care provider if their child shows any signs or symptoms of hepatitis," the authors write. "Additional data from this ongoing investigation are needed to better understand the cause and pathophysiologic mechanism of hepatitis in these patients."