Sex: U
Vaccine: UNK
Symptoms: Febrile convulsion
Clinical narrative: This literature marketed report was received from the authors of a published article and refers to 16 infant patients of unknown gender. The patients' pertinent medical histories, concurrent conditions, drug reactions or allergies were not reported. The authors stated that febrile seizure was the most common type of seizure in childhood, occurring in up to 5% of children; febrile seizure could occur during infections with a variety of pathogens, and it had also been associated with certain types of vaccines; the timing of fever and febrile seizure after vaccination depended on whether the vaccine contains a live attenuated virus, which required several days to replicate before inducing a febrile response, or contained inactivated components, which might elicit a febrile response within the first 24 hours. The literature population had 585,342 vaccination visits, within which 72 patients had an Emergency Department or an inpatient visit associated with a convulsion, however, the Medical records were available for 65 of these patients; there were 31 patients with probable seizures, including 11 seizures without fever, 15 febrile seizures, and five seizures with fever other than febrile seizure. Among the seizures with fever other than febrile seizure, three had a history of prior afebrile seizure and two were originally diagnosed as febrile seizure but were later diagnosed with epilepsy following subsequent afebrile seizures. There were nine patients with possible seizures, among which were five seizures without fever and four febrile seizures. The authors reported 19 probable or possible febrile seizure case patients, on an unknown dates, from 01-JUL-2006 through 30-JUN-2011. The probable febrile seizures all occurred in children aged three to five months, whereas the possible febrile seizures occurred from one to four months of age and the reported seizure duration ranged from five seconds to five minutes. The authors reported 19 probable or possible febrile seizure case patients. On an unknown dates, 16 patients was vaccinated with rotavirus vaccine, live, oral, pentavalent (manufacturer unknown), (dose, dose number, lot number and expiration date were not reported), by oral route, for prophylaxis. Other suspect therapies included hepatitis b vaccine (recombinant) (manufacturer unknown), unspecified Diphtheria-tetanus-acellular pertussis, unspecified Haemophilus influenzae type b, unspecified Inactivated influenza vaccine trivalent, unspecified Inactivated poliovirus, unspecified Monovalent pandemic 2009 H1N1 inactivated influenza vaccine, and unspecified Pneumococcal conjugate; for all, (dose, dose number, route, lot number, and expiration date were not reported), for prophylaxis. On an unknown dates, the 16 infant patients experienced febrile seizure. The authors stated that all vaccines received by the case patients were age appropriate, except for one child who received influenza vaccine at age five months, which was less than the minimum recommended age of six months; the most common combination of vaccines received simultaneously by patients in the present report were rotavirus vaccine, live, oral, pentavalent(manufacturer unknown), hepatitis b vaccine (recombinant) (manufacturer unknown), unspecified Diphtheria-tetanus-acellular pertussis, unspecified Haemophilus influenzae type b, unspecified Inactivated influenza vaccine trivalent, unspecified Inactivated poliovirus, unspecified Monovalent pandemic 2009 H1N1 inactivated influenza vaccine, and unspecified Pneumococcal conjugate. The unspecified Pneumococcal conjugate was independently associated with an increased risk of febrile seizure among children ages six to 23 months in a recent study, however, in the current report, the authors could not determine if the risk observed is due to unspecified Pneumococcal conjugate alone or if other individual vaccines or interactions between vaccines contributed to the observed risk because there were not enough children who did not receive unspecified Pneumococcal conjugate for comparison. The literature article results indicated that febrile seizure risk might increase on the day of or the day after administration of an inactivated vaccine, but not all febrile seizures occurred during this time interval would necessarily be caused by vaccination. In this literature, 32% of patients with a febrile seizure during the risk interval after vaccination had a non-Central Nervous System infection documented at the time of their febrile seizure, which might have led to or contributed to the febrile seizure. Some of these seizures might also be due to noninfectious preexisting conditions that had not yet been diagnosed. In this literature, two patients who initially had a seizure with fever went on to later had afebrile seizures and was diagnosed with epilepsy. So perhaps the diagnosis of an apparent febrile seizure in a child under six months who had a seizure with fever should be considered a provisional diagnosis, with the recognition that the diagnosis might change as the child ages and additional syndromic features present. Additionally, a secondary analysis made by the authors concluded that all seizures with fever in the patients also revealed a significantly increased risk, which could suggest an increased risk of epileptic seizure precipitated by fever following vaccination regardless of the underlying mechanism of seizure susceptibility, then, in as much as certain types of vaccine might elicit fever, and fever in turn might precipitate a seizure in susceptible individuals, this would not be surprising. At the time of reporting, the outcome of febrile convulsion was unknown.