TABLE 1.
Characteristics of the Study Sample, Overall and by Diagnosis of Appendicitis
| Characteristic | All (n = 1010) | Appendicitis | P value | ||||
|---|---|---|---|---|---|---|---|
| Yes (n = 34) | No (n = 976) | ||||||
| n | % | n | % | n | % | ||
| Female sex | 494 | 48.9 | 13 | 38.2 | 481 | 49.3 | 0.205 |
| Age group | <0.001 | ||||||
| 0 yr | 202 | 20.0 | 0 | 0.0 | 202 | 20.7 | |
| 1–2 yr | 229 | 22.7 | 0 | 0.0 | 229 | 23.5 | |
| 3–5 yr | 146 | 14.5 | 5 | 14.7 | 141 | 14.4 | |
| 6–11 yr | 259 | 25.6 | 22 | 64.7 | 237 | 24.3 | |
| 12–17 yr | 174 | 17.2 | 7 | 20.6 | 167 | 17.1 | |
| Delay between onset and diagnosis | 0.061 | ||||||
| 0–1 d | 448 | 44.4 | 20 | 58.8 | 428 | 43.9 | |
| 2–7 d | 469 | 46.4 | 14 | 41.2 | 455 | 46.6 | |
| >7 d | 93 | 9.2 | 0 | 0.0 | 93 | 9.5 | |
| Likely index case | 0.220 | ||||||
| Parent | 290 | 28.7 | 14 | 41.2 | 276 | 28.3 | |
| Sibling | 14 | 1.4 | 0 | 0.0 | 14 | 1.4 | |
| Other | 120 | 11.9 | 1 | 2.9 | 119 | 12.2 | |
| Unknown | 586 | 58.0 | 19 | 55.9 | 567 | 58.1 | |
| Medical history | |||||||
| Known history of BCG vaccine | 760 | 75.2 | 34 | 100.0 | 726 | 74.4 | 0.001 |
| Pre-existing medical conditions | 133 | 13.2 | 7 | 20.6 | 126 | 12.9 | 0.196 |
| Immunosuppressants at the time of diagnosis | 11 | 1.1 | 0 | 0.0 | 11 | 1.1 | 1.000 |
| Primary or secondary immunodeficiency | 8 | 0.8 | 0 | 0.0 | 8 | 0.8 | 1.000 |
| Chemotherapy over the last 6 months | 8 | 0.8 | 0 | 0.0 | 8 | 0.8 | 1.000 |
| Admitted to the hospital | 323 | 32.0 | 34 | 100.0 | 289 | 29.6 | <0.001 |
| Intensive care during hospital stay | 47 | 4.7 | 1 | 2.9 | 46 | 4.7 | 1.000 |
| Symptoms | |||||||
| Pyrexia (≥38.0/≥100.4°C/°F) | 692 | 68.5 | 24 | 70.6 | 668 | 68.4 | 0.791 |
| Upper respiratory tract infection | 468 | 46.3 | 3 | 8.8 | 465 | 47.6 | <0.001 |
| Diarrhea and/or vomiting | 321 | 31.8 | 34 | 100.0 | 287 | 29.4 | <0.001 |
| Lower respiratory tract infection | 217 | 21.5 | 5 | 14.7 | 212 | 21.7 | 0.328 |
| Headache | 105 | 10.4 | 1 | 2.9 | 104 | 10.7 | 0.246 |
| Acute abdomen | 42 | 4.2 | 33 | 97.1 | 9 | 0.9 | <0.001 |
| Chest radiograph | 0.257 | ||||||
| Negative | 194 | 19.2 | 3 | 8.8 | 191 | 19.6 | |
| Positive (pneumonia* and/or ARDS†) | 93 | 9.2 | 4 | 11.8 | 89 | 9.1 | |
| Not performed | 723 | 71.6 | 27 | 79.4 | 696 | 71.3 | |
| Respiratory support | |||||||
| Oxygen support | 118 | 11.7 | 5 | 14.7 | 113 | 11.6 | 0.584 |
| Mechanical ventilation | 31 | 3.1 | 1 | 2.9 | 30 | 3.1 | 1.000 |
| Continuous positive airway pressure (CPAP) | 11 | 1.1 | 0 | 0.0 | 11 | 1.1 | 1.000 |
| Extracorporeal membrane oxygenation (ECMO) | 0 | 0.0 | 0 | 0.0 | 0 | 0.0 | · |
| Administration of inotropes | 29 | 2.9 | 2 | 5.9 | 27 | 2.8 | 0.255 |
| Coinfections detected in respiratory samples(s)‡ | 15 | 1.5 | 1 | 2.9 | 14 | 1.4 | 0.404 |
| Abdominal surgery | 38 | 3.8 | 34 | 100.0 | 4 | 0.4 | <0.001 |
| Drug administration | |||||||
| Systemic corticosteroids | 90 | 8.9 | 2 | 5.9 | 88 | 9.0 | 0.761 |
| Intravenous immunoglobulin (IVIG) | 60 | 5.9 | 3 | 8.8 | 57 | 5.8 | 0.449 |
| Hydroxychloroquine | 9 | 0.9 | 0 | 0.0 | 9 | 0.9 | 1.000 |
| Oseltamivir | 8 | 0.8 | 0 | 0.0 | 8 | 0.8 | 1.000 |
| Lopinavir or ritonavir | 3 | 0.3 | 0 | 0.0 | 3 | 0.3 | 1.000 |
| Noncorticosteroid immunosuppressants | 3 | 0.3 | 0 | 0.0 | 3 | 0.3 | 1.000 |
| Favipiravir | 2 | 0.2 | 0 | 0.0 | 2 | 0.2 | 1.000 |
| Remdesivir | 2 | 0.2 | 0 | 0.0 | 2 | 0.2 | 1.000 |
| MIS-C diagnosis | 0.300 | ||||||
| No | 941 | 93.2 | 31 | 91.2 | 910 | 93.2 | |
| Yes, with no cardiac or joint involvement | 33 | 3.3 | 3 | 8.8 | 30 | 3.1 | |
| Yes, with cardiac involvement§ | 23 | 2.3 | 0 | 0.0 | 23 | 2.4 | |
| Yes, with joint involvement | 11 | 1.1 | 0 | 0.0 | 11 | 1.1 | |
| Yes, with cardiac and joint involvement§ | 2 | 0.2 | 0 | 0.0 | 2 | 0.2 | |
| Tocilizumab administration to treat MIS-C | 8 | 0.8 | 0 | 0.0 | 8 | 0.8 | 1.000 |
| Current status | 0.040 | ||||||
| All symptoms resolved | 989 | 97.9 | 32 | 94.1 | 957 | 98.1 | |
| Dead¶ | 8 | 0.8 | 0 | 0.0 | 8 | 0.8 | |
| Still symptomatic | 7 | 0.7 | 0 | 0.0 | 7 | 0.7 | |
| Long-term sequelae | 6 | 0.6 | 2 | 5.9 | 4 | 0.4 | |
| Country | 0.737 | ||||||
| Peru | 391 | 38.7 | 11 | 32.4 | 380 | 38.9 | |
| Costa Rica | 303 | 30.0 | 14 | 41.2 | 289 | 29.6 | |
| Argentina | 260 | 25.7 | 8 | 23.5 | 252 | 25.8 | |
| Colombia | 44 | 4.4 | 1 | 2.9 | 43 | 4.4 | |
| Mexico | 12 | 1.2 | 0 | 0.0 | 12 | 1.2 | |
*Forty-five cases of interstitial disease, 31 cases of consolidation, 4 cases of pleural effusion and 13 unspecified diagnoses.
†Three cases of interstitial disease, 3 cases of consolidation and 10 unspecified diagnoses.
‡Eight mycoplasmas, 4 rhinoviruses, 1 cytomegalovirus, 1 Epstein–Barr virus and 1 unspecified virus.
§Ten cases of pericardial effusion, 6 cases of coronary dilatation, 5 cases of myocarditis and 4 cases of “other” cardiac involvement.
¶Mean time from symptom onset to death was 14 ± 8 days, ranging from 3 to 27.
ARDS indicates acute respiratory distress syndrome; BCG, bacillus Calmette–Guérin; COVID-19, coronavirus disease 2019; IgG, immunoglobulin G; MIS-C, multisystem inflammatory syndrome; PCR, polymerase chain reaction; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2.