Pediatric Hepatitis Levels Remain Consistent With Pre-Pandemic Levels

Rates of pediatric acute hepatitis cases held steady during the COVID-19 pandemic compared with pre-pandemic levels, according to the CDC’s Morbidity and Mortality Weekly Report (MMWR).

Researchers from the National Center for Immunization and Respiratory Diseases evaluated data from hepatitis-associated emergency department (ED) visits and hospitalizations, liver transplantations, and adenovirus stool testing results in pediatric patients in the United States.

First, the investigators identified a cohort of previously healthy pediatric patients with hepatitis of unknown etiology found at a single US hospital in November 2021. After the CDC requested additional data on pediatric hepatitis cases of unknown etiology in April 2022, the test results were positive for adenovirus, which has not been found to cause hepatitis in immunocompetent pediatric patients.

Although adenovirus hepatitis is not uncommon in immunocompromised patients, the virus is not a recognized cause of hepatitis in healthy pediatric patients.

However, acute hepatitis of unknown etiology and adenovirus type 41 are not reportable in the United States, which creates a challenge around whether levels of infection are approaching historic levels. Four data sources did not identify recent increases in hepatitis-associated ED visits or hospitalizations, liver transplants, or adenovirus types 40/41 percent positivity among pediatric patients versus pre–COVID-19 pandemic levels.

“These data do not suggest an increase in pediatric hepatitis or adenovirus types 40/41 above baseline levels,” the authors wrote. “Pediatric hepatitis is rare, and the relatively low weekly and monthly counts of associated outcomes limit the ability to interpret small changes in incidence.”

The study authors compared data from October 2021-March 2022 with a pre-COVID-19 pandemic baseline with data from the National Syndromic Surveillance Program (NSSP), the Premier Healthcare Database Special Release (PHD-SR), the Organ Procurement, and Transplant Network (OPTN), and Labcorp. Weekly numbers of ED visits were analyzed using a modified Farrington Method to compare them with monthly hospitalizations and liver transplants via the Wilcoxon rank sum test.

The researchers did not find growth in weekly ED visits with hepatitis-associated discharge codes during the pandemic among patients 0-4 years of age or 5-11 years of age versus pre-pandemic data. Between January 2019 and March 2022, researchers noted a median of 22 and 10 hepatitis-associated hospitalizations in those age groups, respectively, which were recorded each month.

They did not find any significant changes in hepatitis-associated hospitalizations during the pandemic study period versus the same months prior to COVID-19 among pediatric patients 0–4 years of age (22 and 19.5, respectively, P = 0.26) or 5–11 years of age (12 and 10.5, respectively, P = 0.42).

A median of 4 liver transplants were performed in those younger than 18 years of age during each month between January 2017 and March 2022. However, they did not find significant growth in total monthly liver transplants between October 2021 and March 2022 versus the same time period between 2017-2019 (P = 0.19).

Monthly adenovirus tests ranged from 184-1759 between October 2017 and March 2022 among pediatric patients 0-4 years of age and from 140-725 among children 5-9 years of age during the same time period. The monthly percentage positive results for adenovirus types 40/41 were from 5%-19% among those 0–4 years of age and from 3%-14% among those 5–9 years of age between October-March 2017-2018, 2018-2019, and 2019-2020.

“After a decrease in testing volume and percentage positive during April 2020–September 2021, the percentage of specimens positive for adenovirus types 40/41 during October 2021–March 2022 returned to, but did not exceed, prepandemic levels in both age groups,” the authors wrote.

However, there are plans to continue to assess trends, as well as conduct enhanced epidemiologic investigations to help contextualize reported cases of acute hepatitis of unknown etiology in US children.

“Current data do not suggest an increase in pediatric hepatitis or adenovirus types 40/41 above pre–COVID-19 pandemic baseline levels; continued surveillance is important to monitor changes over time,” the authors wrote.

Reference

Trends in Acute Hepatitis of Unspecified Etiology and Adenovirus Stool Testing Results in Children — United States, 2017–2022. CDC. Accessed July 11, 2022. https://www.cdc.gov/mmwr/volumes/71/wr/mm7124e1.htm#contribAff