Table 3. Investigation for possible etiology for pediatric acute hepatitis of unknown etiology in Korea.
| Test | Number of tests performed | Number of positive results | |||||
|---|---|---|---|---|---|---|---|
| Surveillance | Control | P value | Surveillance | Control | P value | ||
| Blood | |||||||
| Adenovirus (Blood/Stool/Respiratory) PCRa | 80 (97.6%) | 69 (36.7%) | < 0.001* | 11 (13.8%) | 6 (8.7%) | 0.443 | |
| 67/69/76 | 0/15/63 | 0/9/6 | 0/0/6 | ||||
| AAV2 PCRa | 67 (81.7%) | 0 | 4 (6.0%) | ||||
| Epstein Barr virus (PCR/serology) | 74 (90.2%) | 149 (79.3%) | < 0.001* | 11 (14.9%) | 13 (8.7%) | 0.164 | |
| Cytomegalovirus (PCR/serology) | 74 (90.2%) | 140 (74.5%) | < 0.001* | 9 (11.0%) | 23 (16.4%) | 0.546 | |
| Enterovirus PCRa | 56 (68.3%) | 12 (6.4%) | < 0.001* | 1 (1.8%) | 0 | 0.086 | |
| Human herpes virus-6 PCR | 3 (3.7%) | 11 (5.9%) | 0.562 | 1 (33.3%) | 1 (0.5%) | 0.482 | |
| Parvovirus B19 PCR | 8 (9.8%) | 25 (13.3%) | 0.545 | 0 | 2 (8%) | 0.533 | |
| Herpes simplex virus-1 and 2 PCR | 5 (6.1%) | 18 (9.6%) | 0.478 | 0 | 0 | NA | |
| Varicella zoster virus PCR/IgM | 3 (3.7%) | 4 (2.1%) | 0.759 | 0 | 0 | NA | |
| Leptospira Ab | 1 (1.2%) | 1 (0.5%) | 0.516 | 0 | 0 | NA | |
| Anti-streptolysin O antibody | 11 (13.4%) | 22 (11.7%) | 0.690 | 0 | 2 (10.1%) | 0.529 | |
| Anti-human immunodeficiency virus | 10 (12.2%) | 23 (12.2%) | 1.000 | 0 | 0 | NA | |
| Positive for blood culture | 59 (72%) | 125 (66.5%) | 0.398 | 1b (1.7%) | 3c (2.4%) | 0.644 | |
| Stool | |||||||
| Enterovirus PCRa | 58 (70.7%) | 34 (18.1%) | < 0.001* | 3 (5.1%) | 0 | ||
| Salmonella PCRa/culture | 69 (84.1%) | 34 (18.1%) | < 0.001* | 2 (2.9%) | 0 | 1.000 | |
| Shigella PCRa/culture | 67 (81.7%) | 34 (18.1%) | < 0.001* | 0 | 0 | NA | |
| Campylobacter PCRa/culture | 66 (80.5%) | 34 (18.1%) | < 0.001* | 0 | 0 | NA | |
| E. coli O157 PCRa/culture | 65 (79.3%) | 34 (18.1%) | < 0.001* | 1 (1.5%) | 0 | 1.000 | |
| Norovirus PCRa | 71 (86.6%) | 34 (18.1%) | < 0.001* | 6 (8.5%) | 1 (2.9%) | 0.424 | |
| Sapovirus PCRa | 66 (80.5%) | 34 (18.1%) | < 0.001* | 3 (4.5%) | 0 | 0.549 | |
| Rotavirus PCR | 47 (57.3%) | 34 (18.1%) | < 0.001* | 2 (4.3%) | 0 | 0.507 | |
| Respiratory | |||||||
| SARS-CoV-2 PCRa | 74 (90.2%) | 131 (69.7%) | < 0.001* | 11 (14.9%) | 8 (6.1%) | 0.046 | |
| Influenza PCRa | 76 (92.7%) | 63 (33.5%) | < 0.001* | 2 (2.6%) | 0 | 0.501 | |
| Respiratory syncytial virus PCRa | 75 (91.5%) | 65 (34.6%) | < 0.001* | 6 (8.0%) | 0 | 1.000 | |
| Rhinovirus PCR | 61 (74.4%) | 63 (33.5%) | < 0.001* | 12 (19.7%) | 9 (14.3%) | 0.479 | |
| Parainfluenza virus PCR | 61 (74.4%) | 63 (33.5%) | < 0.001* | 5 (8.2%) | 5 (7.9%) | 1.000 | |
| Human coronavirus PCR | 61 (74.4%) | 63 (33.5%) | < 0.001* | 1 (1.6%) | 0 | 0.492 | |
| Bocavirus PCR | 61 (74.4%) | 63 (33.5%) | < 0.001* | 2 (3.3%) | 1 (1.6%) | 0.616 | |
| Metapneumovirus PCR | 61 (74.4%) | 63 (33.5%) | < 0.001* | 4 (6.6%) | 1 (1.6%) | 0.204 | |
| Throat culture | 6 (7.3%) | 0 | 0.001 | 0 | NA | NA | |
| Urine | |||||||
| Toxin | 5 (6.1%) | 0 | 0.002 | 0 | NA | NA | |
| Leptospira | 2 (2.4%) | 0 | 0.091 | 0 | NA | NA | |
PCR = polymerase chain reaction, AAV2 = adenovirus associates virus-2, Ig = immunoglobulin, E. coli = Escherichia coli, NA = not applicable.
aTest supported by the Korea Centers for Disease Control and Prevention.
b Escherichia coli, Staphylococcus epidermidis, Staphylococcus hominis.
c Klebsiella pneumoniae.
*The P value is less than 0.05 in the analysis between the surveillance group (May to November 2022) and control subgroup (May to November 2021).