Volume 29, Number 6—June 2023
Research Letter
National Surveillance of Pediatric Acute Hepatitis of Unknown Etiology, Japan, October 2021–December 2022
, Itsuro Yoshimi, Tomoya Saito, and Tomimasa Sunagawa
Table
Characteristics and laboratory findings of 139 cases that fulfilled the working case definition of pediatric acute hepatitis of unknown etiology, Japan, October 2021–December 2022*
| Characteristic | Value |
|---|---|
| Median age, y (IQR) | 4.4 (1.3–9.5) |
| <6 y of age |
81/139 (58) |
| Sex | |
| M | 74/139 (53) |
| F |
65/139 (47) |
| Any comorbidities† | 37/139 (26) |
| No comorbidities | 98/139 (71) |
| Presence of comorbidities unknown |
4/139 (3) |
| History of COVID-19 before onset of disease | 15/132 (11) |
| Median duration from COVID-19 onset to hepatitis onset, d (range) | 85 (14–300) |
| Persons >5 y who received >1 dose of COVID-19 vaccine | 22/66 (33) |
| Any international travel in 2 mo before illness | 0/130 (0) |
| Any contact with sick persons in 2 wk before illness |
39/129 (30) |
| Treatment | |
| Steroid therapy | 15/139 (11) |
| Immunoglobulin | 6/139 (4) |
| Plasmapheresis | 6/139 (4) |
| Hemodialysis | 4/139 (3) |
| Liver transplantation |
3/139 (2) |
| Outcome | |
| Acute liver failure | 11/85 (13)‡ |
| Hospitalized to ICU or HCU | 17/95 (18) |
| Death |
0/139 (0) |
| Median duration from symptom onset to hospital admission, d (IQR) | 4 (2–7.5) |
| Median length of hospital stay, d (IQR) |
10 (7–16) |
| Clinical symptoms§ | |
| Fever 37.5°C or higher | 89/138 (64) |
| Gastrointestinal symptoms: abdominal pain, diarrhea, or nausea/vomiting | 75/138 (54) |
| Cough | 29/138 (21) |
| Jaundice | 29/138 (21) |
| White stools | 10/138 (7) |
| Impaired consciousness |
6/138 (4) |
| Median AST, IU/L (IQR)¶ | 764 (503–1,312) |
| Median ALT, IU/L (IQR)¶ | 838 (576–1,390) |
| Median total bilirubin, mg/dL (IQR)¶ | 1.00 (0.60–4.74) |
| Median PT-INR (IQR)¶ |
1.11 (1.02–1.32) |
| No. SARS-CoV-2 positive/no. tested (%) | 10/134 (7) |
| Nucleic acid amplification test: PCR 101, LAMP 1, and NEAR 1 | 8/103 (8) |
| Antigen test | 2/13 (15) |
| Type of test unknown | 0/18 (0) |
*Values are no. (%) except as indicated. Denominators consist of cases for which data are available. ALT, alanine aminotransferase; AST, aspartate aminotransferase; HCU, high-care unit; ICU, intensive care unit; IQR, interquartile range; LAMP, loop-mediated Isothermal amplification; NEAR, nicking enzyme amplification reaction; PT-INR, prothrombin time and international normalized ratio. †Specific underlying conditions reported were psychomotor retardation (11, 8%), syndromes involving changes in chromosomes or genes (5, 4%), congenital heart disease (4, 3%), congenital metabolic disorder (3, 2%), low birthweight (3, 2%), endocrine disorder (3, 2%), autoimmune and collagen diseases (3, 2%), primary immunodeficiency syndrome (2, 1%), and other disorders (8, 6%) (atopic dermatitis, cloacal exstrophy, hydronephrosis, unilateral kidney agenesis and haemangioma). ‡Including 3 patients with encephalopathy. §Some patients reported >1 sign/symptom. ¶Maximum values up to the time of reporting. Based on information from 136 (AST and ALT), 99 (total bilirubin), and 85 (PT-INR) cases.