Bacterial meningitis epidemiology and return of Neisseria meningitidis serogroup A cases in Burkina Faso in the five years following MenAfriVac mass vaccination campaign.

Background: Historically, Neisseria meningitidis serogroup A (NmA) caused large meningitis epidemics in sub-Saharan Africa. In 2010, Burkina Faso became the first country to implement a national meningococcal serogroup A conjugate vaccine (MACV) campaign. We analyzed nationwide meningitis surveillance data from Burkina Faso for the 5 years following MACV introduction.

Methods: We examined Burkina Faso's aggregate reporting and national laboratory-confirmed case-based meningitis surveillance data from 2011-2015. We calculated incidence (cases per 100,000 persons), and described reported NmA cases.

Results: In 2011-2015, Burkina Faso reported 20,389 cases of suspected meningitis. A quarter (4,503) of suspected meningitis cases with cerebrospinal fluid specimens were laboratory-confirmed as either S. pneumoniae (57%), N. meningitidis (40%), or H. influenzae (2%). Average adjusted annual national incidence of meningococcal meningitis was 3.8 (range: 2.0-10.2 annually) and was highest among infants aged <1 year (8.4). N. meningitidis serogroup W caused the majority (64%) of meningococcal meningitis among all age groups. Only six confirmed NmA cases were reported in 2011-2015. Five cases were in children who were too young (n = 2) or otherwise not vaccinated (n = 3) during the 2010 MACV mass vaccination campaign; one case had documented MACV receipt, representing the first documented MACV failure.

Conclusions: Meningococcal meningitis incidence in Burkina Faso remains relatively low following MACV introduction. However, a substantial burden remains and NmA transmission has persisted. MACV integration into routine childhood immunization programs is essential to ensure continued protection.