Letter to the editor
Acute hepatitis of unknown etiology: a proposed diagnostic
approach
Hepatitis aguda de etiología desconocida: una propuesta de abordaje
diagnóstico
Rubén Peña-Vélez1
*
Alfredo Y. Martínez-Vázquez2
Lucía Pérez-Ricárdez3
1Unidad de Gastroenterología, Hepatología y
Nutrición Pediátrica, Hospital General de Puebla Dr. Eduardo Vázquez
N.
2Servicio de Gastroenterología y Nutrición,
Hospital para el Niño Poblano
3Servicio Infectología, Hospital para el Niño
Poblano. Puebla, Puebla, Mexico
Recently, acute and severe hepatitis cases in children have increased, triggering close
epidemiological surveillance worldwide1. Between
April 5 and May 26, 2022, 650 probable cases have been reported to the World Health
Organization (WHO) from 33 countries, with the United Kingdom and the United States
reporting most cases, followed by Japan, Spain, and Italy2.
The WHO defines a probable case as any person presenting with acute hepatitis (not
hepatitis A-E) with serum transaminase levels > 500 IU/L (aspartate aminotransferase or
alanine aminotransferase) and age ≤ 16 years (Table
1)3, mainly with gastrointestinal
symptoms, such as vomiting, acholia, and jaundice, and respiratory symptoms in a lower
percentage (Table 2)2.
Table 1 Case definitions according to the World Health Organization
Case |
Definition |
Confirmed |
No definition |
Probable |
Any individual aged ≤ 16 years who presents acute hepatitis
(not hepatitis A-E), with serum transaminase levels > 500 IU/L (AST or
ALT) since October 1, 2021 |
Contact |
Any individual of any age who presents with acute hepatitis
(not hepatitis A-E) and has been in close contact with a probable case
since October 1, 2021 |
Cases with other explanations for clinical
presentation should be excluded. Delta testing is not required,
as it is only performed in HBsAg-positive individuals to establish the
presence of coinfection |
AST, aspartate aminotransferase; ALT, alanine aminotransferase; HBsAg,
hepatitis B virus surface antigen.
Table 2 Clinical presentation in children with acute hepatitis of unknown
etiology
Signs or symptoms |
Percentage |
Jaundice |
71% |
Vomiting |
63% |
Acholia |
50% |
Diarrhea |
45% |
Fever |
31% |
Respiratory symptoms |
19% |
Etiology of acute hepatitis
Cases have tested negative for A-E viruses. A UK study involving 126 children
documented the presence of adenovirus in 72% (n = 91). It was also identified in 44%
of stool and 29% of respiratory specimens. Twenty-four children (18%) had active
SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) infection.
Epstein-Barr, enterovirus, cytomegalovirus, respiratory syncytial virus, and human
herpesviruses 6 and 7 were identified less frequently4-6.
According to the European Centre for Disease Prevention and Control (ECDC), several
hypotheses have emerged based on present-day evidence. The most compelling relates
to a cofactor affecting children that cause mild adenovirus infections to become
more severe or trigger immune-mediated liver damage. This cofactor may be related to
susceptibility due to a lack of prior exposure to adenovirus during the pandemic, a
previous SARS-CoV-2 infection, or a toxin, drug, or environmental exposure1,7.
Proposed diagnostic approach
Upon identification of a probable case of hepatitis, the conventional care process
should be conducted, allowing for differential diagnosis since acute hepatitis is
not a new disease. Throughout history, cases of unknown or idiopathic causes have
been documented after searching for the most common causes. For this reason, it is
necessary to adopt a systematic evaluation, tiered by the level of care and age
group, to manage cases with symptoms consistent with acute hepatitis (Figure 1).
This evaluation is intended to determine the etiology of the liver injury and not
ignore other known causes of hepatitis, such as autoimmune, toxic, and other
infectious diseases caused by hepatotropic and non-hepatotropic viruses, including
hemophagocytic lymphohistiocytosis, in which patients present with hepatic
inflammation and may develop acute liver failure8.
Acknowledgments
For the preparation of this document, the opinion of a multidisciplinary team was
considered: Dr. Gloria Ramos (Pediatric Toxicologist, Secretary of Health, Puebla,
Mexico), Dr. Rosa Angélica Castillejos Blake (Pediatric Intensivist, Hospital para
el Niño Poblano, Puebla, Mexico), Dr. Olivia López (Pediatrician, Hospital General
de Cholula, Puebla, Mexico), Dr. Maria de Lourdes Fabiola Sánchez (Pediatrician,
Hospital General de Puebla Dr. Eduardo Vázquez N., Puebla, Mexico), Dr. Leonor
Urbina (Pediatrician, Hospital General Norte, Puebla, Mexico), Dr. Maricruz
Gutiérrez Brito (Epidemiologist, Hospital para el Niño Poblano. Puebla, Mexico), Dr.
Sharon Imbett (Pediatric Gastroenterologist, Clínica del Rosario/Centro de
Endoscopia y Colonoscopia Pediátrica, Medellín, Colombia) and Dr. Fernando Huerta
(Pediatric Infectologist, Secretary of Health, Puebla, Mexico).
References
1. Cevik M, Rasmussen AL, Bogoch II, Kindrachuk J. Acute hepatitis
of unknown origin in children. BMJ. 2022;377:o1197.
[ Links ]
2. World Health Organization. Acute hepatitis of unknown aetiology
in children—Multi-country. Geneva:World Health Organization;2022. Available
from:https://www.who.int/emergencies/disease-outbreak-news/item/DON-389
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3. World Health Organization. Disease outbreak news:Severe acute
hepatitis of unknown aetiology in children–Multi-country. Geneva:World Health
Organization;2022. Available
from:https://www.who.int/emergencies/disease-outbreak-news/item/2022-DON376.
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4. Baker JM, Buchfellner M, Britt W, Sanchez V, Potter JL, Ingram
LA, et al. Acute hepatitis and adenovirus infection among children—Alabama,
October 2021-February 2022. MMWR Morb Mortal Wkly Rep.
2022;71:638-40.
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5. Marsh K, Tayler R, Pollock L, Roy K, Lakha F, Ho A, et al.
Investigation into cases of hepatitis of unknown aetiology among young children,
Scotland, 1 January 2022 to 12 April 2022. Euro Surveill.
2022;27:2200318.
[ Links ]
6. UK Health Security Agency. Baillie K, Baldevarona J, Bindra R,
Bradshaw D, Breuer J, Blomquiste P, et al. Investigation into acute hepatitis of
unknown aetiology in children in England—technical briefing. London:UK Health
Security Agency;2022. Available
from:https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/1073704/acute-hepatitis-technical-briefing-2.pdf.
[ Links ]
7. European Centre for Disease Prevention and Control. Increase in
severe acute hepatitis cases of unknown aetiology in children.
Stockholm:European Centre for Disease Prevention and Control;2022. Available
from:https://www.ecdc.europa.eu/sites/default/files/documents/RRA-20220420-218-erratum.pdf.
[ Links ]
8. Squires JE, Alonso EM, Ibrahim SH, Kasper V, Kehar M, Martinez M,
et al. North American Society for Pediatric Gastroenterology, Hepatology, and
Nutrition position paper on the diagnosis and management of pediatric acute
liver failure. J Pediatr Gastroenterol Nutr. 2022;74:138-58.
[ Links ]
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