#16,823
A little over 2 months ago, in UK HSA: Investigating An Unusual Increase In Hepatitis In Children, we first learned of cluster of acute hepatitis (including liver failure) among young children in the UK. In the weeks that would follow, we'd see similar reports from many countries, including the United States (see CDC Telebriefing Today On Acute Hepatitis Of Unknown Cause).
At last report, the UK had identified 240 cases - mostly in children under the age of 5 - and while the cause remains unknown, their investigation continues to suggest a strong association with adenovirus infection.
Although adenovirus is not normally associated with severe liver damage, the CDC has also asked clinicians to test for the virus in suspected cases (see CDC HAN: Updated Recommendations for Adenovirus Testing and Reporting of Children with Acute Hepatitis of Unknown Etiology).
The UK's preliminary findings will supposedly be published tomorrow, June 16th.
In the meantime we have an MMWR report, published yesterday, that - based on limited data - doesn't find any evidence that the number of cases of acute hepatitis of unknown origin in children has increased since the start of the COVID pandemic.
The authors caution that this study is subject to at least 7 limitations:
- First, although liver transplants are well-documented, cases of hepatitis of unknown etiology are not reportable in the United States. This analysis assessed trends using electronic health data on pediatric hepatitis of unspecified etiology as a proxy, but the exact baseline remains unknown, as does the accuracy and completeness of the diagnostic codes used for identification.
- Second, data on hospitalizations and liver transplants have up to a 2–3-month lag between outcome and report; March 2022 data might be underreported.
- Third, the COVID-19 pandemic likely affected observed patterns during the analysis period because of its effects on health care–seeking behavior (9) and infectious disease epidemiology during 2020–2021, and these patterns might still be normalizing. Prepandemic data are limited to 2017–2019, and it is not known whether these data represent a reliable baseline.
- Fourth, although NSSP and PHD-SR capture a large number of ED visits and hospitalizations, respectively, they do not cover the entire U.S. population, nor do they represent the same catchment areas. Similarly, Labcorp data represent only one large laboratory network and are not deduplicated to the patient level. The extent to which changes in testing volume might be due to changes in laboratory market share or test-ordering practices could not be determined, although the percentage of positive test results should not be substantially affected.
- Fifth, although the Labcorp assay cannot distinguish between adenovirus types 40 and 41, nearly 90% of adenovirus detections in U.S. children with gastroenteritis are type 41 (10).
- Sixth, cases of acute hepatitis of unknown etiology are generally rare; thus, small changes in incidence might be difficult to detect and interpret.
- Finally, these results are intended to provide an overview of trends in pediatric acute hepatitis of unspecified etiology and adenovirus types 40/41 in the United States and cannot be used to infer or disprove a causal link between these two illnesses.
You'll want to follow the link and read the report in its entirety, as I've only reproduced the summary and excerpts from the discussion section below.
Trends in Acute Hepatitis of Unspecified Etiology and Adenovirus Stool Testing Results in Children — United States, 2017–2022
Early Release / June 14, 2022 / 71
Anita K. Kambhampati, MPH1; Rachel M. Burke, PhD1; Stephanie Dietz, PhD2; Michael Sheppard, MS2; Olivia Almendares, MSPH1; Julia M. Baker, PhD1,3; Jordan Cates, PhD1; Zachary Stein, MPH2,4; Dylan Johns, MS2,4; Amanda R. Smith, PhD2,3; Lara Bull-Otterson, PhD2; Megan G. Hofmeister, MD5; Stacy Cobb, PhD2,6; Suzanne E. Dale, PhD7; Karl A. Soetebier, MAPW2; Caelin C. Potts, PhD1; Jennifer Adjemian, PhD2; Aaron Kite-Powell, MS2; Kathleen P. Hartnett, PhD2; Hannah L. Kirking, MD1; David Sugerman, MD1; Umesh D. Parashar, MD, MBBS1; Jacqueline E. Tate, PhD1 (View author affiliations)View suggested citation
Summary
What is already known about this topic?
Following identification of pediatric hepatitis cases of unknown etiology in the United States and the United Kingdom, CDC issued a request in April 2022 for U.S. providers to report additional cases. Many reported cases had test results positive for adenovirus, which is not known to cause hepatitis in immunocompetent children.
What is added by this report?
Analyses of four data sources did not indicate recent increases in hepatitis-associated emergency department visits or hospitalizations, liver transplants, or adenovirus types 40/41 percent positivity among U.S. children compared with pre–COVID-19 pandemic levels.
What are the implications for public health practice?
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.
(SNIP)
These analyses, based on four data sources, did not indicate a recent increase in hepatitis-associated ED visits or hospitalizations among children aged 0–11 years, liver transplants among children aged 0–17 years, or percentage of specimens positive for adenovirus types 40/41 among children aged 0–9 years in the United States compared with pre–COVID-19 pandemic levels.
The potential role of adenovirus in the etiology of the newly reported hepatitis cases is unknown; ongoing investigations are assessing this hypothesis along with the possible role of other factors, including current or past infections with SARS-CoV-2, the virus that causes COVID-19.It remains unknown whether the recently reported cases represent a novel etiology of pediatric acute hepatitis or a previously existing phenomenon that is now being detected. The rarity of this outcome makes it difficult to detect small changes, and pandemic-associated disruptions in health care–seeking behavior and infectious disease epidemiology might still be normalizing. 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.
