TABLE 1.
Characteristics of Patients With a Probable or Possible Febrile Seizure Following Vaccination as Determined by Medical Record Abstraction
| Characteristics | Probable Febrile Seizure n = 15 | Possible Febrile Seizure n = 4 | Total N = 19 |
|---|---|---|---|
| Age (months) | |||
| 1 | 0 | 1 | 1 (5%) |
| 2 | 0 | 1 | 1 (5%) |
| 3 | 4 | 1 | 5 (26%) |
| 4 | 9 | 1 | 10 (53%) |
| 5 | 2 | 0 | 2 (11%) |
| Sex | |||
| Male | 8 | 3 | 11 (58%) |
| Female | 7 | 1 | 8 (42%) |
| Medical history before seizure | |||
| Premature birth | 0 | 1 | 1 (5%) |
| Family history of febrile seizure | 2 | 1 | 3 (16%) |
| Temperature >38°C at the time of vaccination | 1 | 0 | 1 (5%) |
| Vaccines received on day 0 | |||
| Number, median (range) | 4 (2 to 6) | 4 (2 to 4) | 4 (2 to 6) |
| HepB | 1 | 0 | 1 (5%) |
| RV5 | 12 | 4 | 16 (84%) |
| DTaP-HepB-IPV combination vaccine | 11 | 3 | 14 (74%) |
| DTaP-IPV/Hib combination vaccine | 2 | 1 | 3 (16%) |
| Hib | 13 | 3 | 16(84%) |
| PCV 7-valent | 14 | 3 | 17(89%) |
| PCV 13-valent | 1 | 0 | 1 (5%) |
| IIV3 | 1 | 0 | 1 (5%) |
| MIV | 1 | 0 | 1 (5%) |
| Seizure characteristics | |||
| Duration not reported | 6 | 1 | 7 (37%) |
| Duration reported in minutes, median (range) | 1 (0.3 to 5.0) | 0.17 (0.08 to 0.25) | 0.6 (0.08 to 5.0) |
| Complex febrile seizure | 4 | 0 | 4 (21%) |
| Medical visit for febrile seizure | |||
| Non-CNS infection documented* | 5 | 1 | 6 (32%) |
| Seizure witnessed by a health care provider | 2 | 0 | 2(11%) |
| Provider notes used the term “febrile seizure” to label the diagnosis | 9 | 3 | 12(63%) |
| Patient admitted to the hospital | 6 | 3 | 9 (47%) |
Abbreviations:
CNS = Central nervous system
DTaP = Diphtheria-tetanus-acellular pertussis
HepB = Hepatitis B
Hib = Haemophilus influenzae type b
IIV3 = Inactivated influenza vaccine trivalent
IPV = Inactivated poliovirus
MIV = Monovalent pandemic 2009 H1N1 inactivated influenza vaccine
PCV = Pneumococcal conjugate
RV5 = Rotavirus vaccine pentavalent
*
The five probable cases with infection all occurred during the risk interval, and the one possible case with infection occurred during the control interval.