Hospital-based Sentinel Surveillance of Haemophilus Influenzae Type B among Children in Burkina Faso, 2004-2012: Impact of Vaccine Introduction

Background: Haemophilus influenzae type b (Hib) is a leading cause of childhood bacterial meningitis in Africa. This study assessed the impact of Hib conjugate vaccine introduced in 2006 into the Expanded Program on Immunization (EPI) in Burkina Faso. Methods: From 2004-2012, we conducted hospital-based surveillance for invasive Hib disease among children <5 years of age with suspected bacterial meningitis. All cerebrospinal fluid (CSF) samples were tested using culture methods and/or PCR. Incidences calculated using population denominators were compared between pre-vaccine (2004-2005) and post- vaccine (2007-2012) periods. Results: 3928 cases of suspected meningitis were identified from the pediatric service, 231(5.9%) of whom had a bacterial pathogen confirmed. Hib was found in 80 (34.6%) of confirmed cases, followed by Streptococcus pneumoniae in 76 (32.90%) and Neisseria meningitidis in 54 (23.38%). The average annual incidence (per 1,00,000 children) of Hib meningitis was 4.11; the annual incidence of Hib meningitis declined by 94.13% from 16 per 1,00,000 in pre-vaccine (2004-2005) to 0.94 per 100 000 in post-vaccine (2007-2012) periods. None of the 80 Hib confirmed cases was immunized and no death was notified after the introduction of the vaccine. Conclusion: Admissions for Hib meningitis in the department of pediatrics at University Hospital, CHU-Yalgado Ouedraogo have practically disappeared two years after the introduction of the Hib vaccine into Burkina Faso’s Expanded Program on Immunization.