Bacterial Meningitis Epidemiology in Burkina Faso and Niger - High-Risk Countries in the Meningitis Belt of Sub-Saharan Africa, 2015-2023.

Abstract

Burkina Faso and Niger experience hyperendemic meningitis. We describe their bacterial meningitis epidemiology during 2015-2023, after meningococcal A and prior to meningococcal ACWYX (Men5CV) conjugate vaccine introductions. Case-based surveillance included demographics, clinical information, and cerebrospinal fluid (CSF) specimens from suspected meningitis cases. CSFs were tested by real-time polymerase chain reaction (rt-PCR) and culture to detect Neisseria meningitidis (Nm), Streptococcus pneumoniae (Sp), or Haemophilus influenzae (Hi). Nm serogroup (A, C, W, Y, X, B or indeterminate) was established by rt-PCR or slide agglutination. Annual incidences were calculated using country census estimates as population denominators. During 2015-2023, 20,538 suspect cases were reported in Burkina Faso and 18,047 in Niger. In Burkina Faso, 3,722/16,350 CSF specimens tested were positive; 2,357 (64%) were Sp and 512 (14%) Nm serogroup W; Hi and Nm serogroups A, C, X, and indeterminate were also detected (<1-9% each). In Niger, 4,372/11,076 CSF specimens tested were positive; 3,003 (69%) were Nm serogroup C and 703 (16%) Sp; Hi and Nm serogroups B, W, X, and indeterminate were also detected (<1-8% each). Average annual incidences per 100,000 population of Nm, Sp, and Hi were 0.7, 1.6, and 0.2 for Burkina Faso and 4.1, 0.8, and 0.2 for Niger. Children ages 5-9 years in Burkina Faso and 10-14 years in Niger had the highest Nm incidences. Nm, Sp and Hi continue to cause disease in Burkina Faso and Niger. Men5CV could help address the burden of serogroup C, W, and X meningococcal disease.