Demographic and clinical details of 63 children aged 6 months to 4 years presenting with febrile convulsions within 72 h of receiving trivalent inactivated influenza vaccine during the investigation period, 8 March to 25 April 2010
| Febrile convulsion presentations (n=63) | ||
| Demographics and past history | Mean age (years) | 1.85 |
| Median age (years) | 1.53 | |
| Male gender | 38 (60.3%) | |
| History of febrile convulsions | 8 (12.7%) | |
| History of seizures (other than febrile convulsions) | 3 (4.8%) | |
| History of AEFI | 4 (6.3%) | |
| Chronic medical condition* | 7 (11.1%) | |
| Symptoms on presentation | Fever (self-report) | 63 (100%) |
| Recorded temperature ≥38°C | 57 (90%) | |
| Rigors | 28 (44.4%) | |
| Respiratory | 12 (19.0%) | |
| Vomiting | 36 (57.1%) | |
| Fatigue | 22 (34.9%) | |
| Diarrhoea | 3 (4.8%) | |
| Headache | 3 (4.8%) | |
| Rash | 10 (15.9%) | |
| Local swelling | 3 (4.8%) | |
| Clinical | Admitted to hospital | 28 (44.4%)† |
| Admitted to intensive care unit | 2 (3.1%) | |
| Sequelae | 1 (1.6%)‡ | |
| Time from vaccination to symptom onset | Median time (h) | 7.0§ |
| Mean time (h) | 8.9§ | |
| Onset within 12 h | 93%§ | |
* Chronic medical conditions included diabetes, chronic heart, respiratory, renal, neurological and blood disease, metabolic disease and impaired immunity.
† Mean length of stay 3 days; range 1–50 days.
‡ Hypoxic ischaemic encephalopathy.
§ Data available for 57 cases.
AEFI, adverse event following immunisation.