Thrombocytopenia: Case definition and guidelines for collection, analysis, and presentation of immunization safety data
University of Oulu, Uleoborg, Northern Ostrobothnia, FinlandVaccine (Impact Factor: 3.62). 09/2007; 25(31):5717-24. DOI: 10.1016/j.vaccine.2007.02.067
Article: 32 Vaccines[Show abstract] [Hide abstract]
ABSTRACT: This chapter discusses different studies conducted to analyze effects of vaccines on patients. The safety and reactogenicity of a booster dose of hexavalent DTaP–HBV–IPV/Hib vaccine has been compared with the separate administration of DTaP–IPV/Hib and HBV vaccines. In the first study, the incidences of symptoms were similar in the two groups; no serious adverse events were either reported within 4 days of immunization or considered to be causally related to immunization. In the second study, in which fever was the only solicited symptom, the rectal temperature was 39.5°C or over in 2.5 and 2.8% of the subjects respectively. Fever of 40.0°C or more was rare (0.6%), and only two cases of febrile convulsions were recorded during the 4 days after immunization, both in the control group. In another study, severe jaundice and raised serum liver enzyme activities were reported after a dose of Twinrix® (combination HA/HB vaccine). Studies on Flumist®, a cold-adapted live attenuated influenza vaccine in young children showed that it is effective against circulating H1N1 and H3N2 strains, including H3N2 strains. However, there was a significantly increased incidence of medically significant episodes of wheezing within 42 days of immunization among children aged 6–23 months.
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ABSTRACT: Demographics, outcome, and management of idiopathic thrombocytopenic purpura (ITP) in children present differences between countries. Although several factors influence outcome, it is impossible to predict at diagnosis which patients will have acute or chronic disease. High rates of spontaneous remission in chronic ITP have been reported. Data concerning 1,683 patients with ITP diagnosed from 1981 to date are presented; outcome was evaluated in 1,418 children. Remarkable presenting features were an incidence peak in the first 2 years of age and male predominance in patients <24 months of age. Three age groups with different recovery rates (P < 0.001) were established (2-12 months: 89.8%; 1-8 years: 71.3%; 9-18 years: 49.0%). Platelet count <10 x 10(9)/L and history of previous illness were associated with higher remission rates only in patients >12 months of age. The score developed by the NOPHO Group showed a predictive value of 83.9% for acute ITP. Spontaneous remission between 6 months and 11 years from diagnosis was achieved by 107 of 325 (32.9%) non-splenectomized children with chronic ITP, and in 44.9% of them between 6 and 12 months from diagnosis. Age and score were main prognostic factors. Infants <1 year of age are a special group with a brief course and very high recovery rate that are not influenced by other prognostic factors. Definition of groups based on age and scoring could be useful to establish differential management guidelines. The cut-off value to define chronic ITP should be changed to 12 months.
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ABSTRACT: Active surveillance data from 12 Canadian tertiary-care hospitals on children hospitalized with postvaccination thrombocytopenia were analyzed. Since 1992, there have been 107 cases reported; while 96% of the children were symptomatic, only 2 had severe bleeding. With treatment, 28 children (26%) had normal platelet counts on discharge from hospital and 93% had documented recovery within 3 months.
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