Impact of introduction of the Haemophilus influenzae type b conjugate vaccine into childhood immunization on meningitis in Bangladeshi infants

Objectives: Some Asian countries have been reluctant to adopt Haemophilus influenzae type b (Hib) conjugate vaccination because of uncertainty over disease burden. We assessed the impact of introduction of Hib conjugate vaccine into the Expanded Program on Immunization in Bangladesh on purulent and laboratory-confirmed H influenzae meningitis.

Study design: Within a well-defined catchment area around 2 surveillance hospitals in Dhaka, Bangladesh, we compared the incidence of Hib meningitis confirmed by culture, latex agglutination, and polymerase chain reaction assay among infants 1 year before and 1 year after introduction of Hib conjugate vaccine. We adjusted the incidence rate for the proportion of children who sought care at the surveillance hospitals.

Results: Among infants, the incidence of confirmed Hib meningitis decreased from 92-16 cases per 100,000 within 1 year of vaccine introduction (vaccine preventable incidence = 76; 95% CI 18, 135 per 100,000). The incidence of purulent meningitis decreased from 1659-1159 per 100,000 (vaccine preventable incidence = 500; 95% CI: 203, 799 per 100,000). During the same time period, there was no significant difference in the incidence of meningitis due to Streptococcus pneumoniae.

Conclusions: Introduction of conjugate Hib conjugate vaccine into Bangladesh Expanded Program on Immunization markedly reduced the burden of Hib and purulent meningitis.