Meningococcal disease before and after the introduction of meningococcal serogroup C conjugate vaccine. Federal District, Brazil.
OBJECTIVE
To analyze the behavior of meningococcal disease in the Federal District, Brazil, from 2005 to 2011, and to assess the direct impact of the meningococcal serogroup C conjugate vaccine.


METHODS
A descriptive study of cases of meningococcal disease among residents of the Federal District. We included in the study confirmed cases of meningococcal disease reported to the local surveillance. To reduce underreporting we compared data to the Brazilian Mortality Database and the Public Health Laboratory Database. We studied sociodemographic, clinical, and pathogen-related variables. For the assessment of the impact of meningococcal serogroup C conjugate vaccine, which was introduced in 2010 for children under two years of age, we compared the incidence of meningococcal disease before and after vaccine introduction in the recommended age groups for vaccination.


RESULTS
We identified 309 cases of meningococcal disease, of which 52.1% were males. The average case fatality rate was 20.7%, the median age was three years and there was a predominance of serogroup C (70.2%) and C:23:P1.14-6 phenotype throughout the study period. In 2005-2009, 2010 and 2011, the incidence rates of meningococcal disease were 2.0, 1.8 and 0.8/100,000 inhabitants/year, while mortality rates were 0.4, 0.4 and 0.2/100,000 inhabitants/year, respectively. In the first and last periods, the incidence in poorer and more affluent areas were, respectively, 2.0 and 0.8, and 0.9 and 0.0/100,000 inhabitants/year. Comparing 2009 (the year prior to the introduction of meningococcal serogroup C conjugate vaccine) and 2011, there was 85% reduction in the incidence of serogroup C meningococcal disease in children under four years of age, from 9.0 to 1.3/100,000 (p<0.01).


CONCLUSIONS
The meningococcal serogroup C conjugate vaccine strategy implemented in Brazil proved highly effective and had a strong direct impact on the target population. However, case fatality rates of meningococcal disease remain high with a wide gap in the risk of disease between poor and affluent areas, pointing to the need to reexamine the current strategy on a regular base.
Faculdade de Saúde Pública da Universidade de São Paulo, São Paulo, SP, Brazil. Electronic address: mctauil@yahoo.com.br.
Márcia de Cantuária
Mde C
Tauil
Gerência de Vigilância Epidemiológica e Imunização, Secretaria de Estado de Saúde do Distrito Federal, Brasília, DF, Brazil.
Cleidiane Santos Rodrigues de
CS
Carvalho
Laboratório Central de Saúde Pública do Distrito Federal, Brasília, DF, Brazil.
Ataiza César
AC
Vieira
Faculdade de Saúde Pública da Universidade de São Paulo, São Paulo, SP, Brazil.
Eliseu Alves
EA
Waldman
D000293:Adolescent; D000328:Adult; D000368:Aged; D001938:Brazil / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D017589:Immunization Programs; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008589:Meningococcal Infections / Q000453:epidemiology* / Q000517:prevention & control*; D022401:Meningococcal Vaccines / Q000008:administration & dosage*; D008875:Middle Aged; D009345:Neisseria meningitidis / Q000276:immunology*; D010641:Phenotype; D011159:Population Surveillance; D015397:Program Evaluation; D055815:Young Adult
D022401:Meningococcal Vaccines; C410218:serogroup C meningococcal conjugate vaccine
Control; Epidemiology; Meningococcal disease