Impacto da vacinação contra o Haemophilus Influenzae tipo B na incidência de meningite no Espírito Santo

• Ano de defesa: 2005
• Autor(a) principal: Martins, Ronaldo Ewald
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal do Espírito Santo; BR; Mestrado em Saúde Coletiva; Centro de Ciências da Saúde; UFES; Programa de Pós-Graduação em Saúde Coletiva
• Palavras-chave em Português: Meningitis, Haemophilus; Vaccination; Prevention & control; Statistics & numeral data; Meningite por Haemophilus - Prevenção - Espírito Santo (Estado); Vacinação - Espírito Santo (Estado); Prevenção e controle; Estatística e dados numéricos; Meningite por haemophilus - Prevenção; Métodos estatísticos; Vacinação; Saúde Coletiva; 614
• Link de acesso: http://repositorio.ufes.br/handle/10/5365

In July 1999, a conjugate vaccine against Haemophilus influenzae type b (Hib) began to be used in children in Espírito Santo State. With the object of evaluating the impact of vaccination on the incidence of meningitis caused by Hib, the State Secretariat of Health (SESA, ES) data were used and a survey of the cases occurred in the period 1993 – 2004 was carried out. Of a total of 406 meningitis Hib cases that occurred during such period, 359 cases which occurred in children under 5 years old were studied, specifying those under 1 year old and the 1 – 4 year-old group. In the year 2000, the State had 77 counties, 3.097.232 inhabitants, and 284.436 children under 5 years old, according to the Brazilian Institute of Geography and Statistics (IBGE). The rates were calculated for 100.000 inhabitants for each age span. The period 1993 – 1999 was considered as pre-vaccine and the period 2000 – 2004 as post-vaccine. The Vaccine was administered at 2, 4, and 6 months of age, with no booster in the first year of life and in a sole dose in the second year. Results showed that in the counties with a larger number of children under 5 years old, the average incidence in the pre-vaccine period was higher than double the average incidence in the counties with a smaller number of children in that age span (12,54 and 4,13, respectively). From the pre-vaccine period to the postvaccine period, the average rate in those under 1 year old declined from 50,57 to 4,88 (p=0,003), and in the 1 – 4 year-old group it declined from 8,43 to 0,86 (p=0,003). The predominant gender was male (54,87%). No statistical predominance was observed in the seasonal distribution of cases. Lethality in those under 5 years old was 15,59%. When detailed by age span, lethality showed 19,81% in those under 1 year old and 9,52% in the 1 – 4 year-old group. The conclusion was that there was a great impact of vaccination upon the incidence of meningitis Hib in children under 1 year old, and also in children 1 – 4 years old, determining a significant change in the rates of the evaluated age spans, and also in the other ages participation rate. The surprising and sudden decline of the rates in children 1 – 4 years old suggested a strong evidence of the occurrence of a mass immunity effect. It was also observed a great alteration in the case rate by age span after vaccination. The children above 5 years old, who represented 8,71% of the cases in the pre-vaccine period, came to represent 38,46% of the cases in the post-vaccine period. The 47 cases that occurred in children above 5 years old were not object of this dissertation, and were only mentioned in the final comments.