title: Baseline meningococcal carriage in Burkina Faso before the introduction of a meningococcal serogroup A conjugate vaccine.
abstract: The serogroup A meningococcal conjugate vaccine MenAfriVac has the potential to confer herd immunity by reducing carriage prevalence of epidemic strains. To better understand this phenomenon, we initiated a meningococcal carriage study to determine the baseline carriage rate and serogroup distribution before vaccine introduction in the 1- to 29-year old population in Burkina Faso, the group chosen for the first introduction of the vaccine. A multiple cross-sectional carriage study was conducted in one urban and two rural districts in Burkina Faso in 2009. Every 3 months, oropharyngeal samples were collected from >5,000 randomly selected individuals within a 4-week period. Isolation and identification of the meningococci from 20,326 samples were performed by national laboratories in Burkina Faso. Confirmation and further strain characterization, including genogrouping, multilocus sequence typing, and porA-fetA sequencing, were performed in Norway. The overall carriage prevalence for meningococci was 3.98%; the highest prevalence was among the 15- to 19-year-olds for males and among the 10- to 14-year-olds for females. Serogroup Y dominated (2.28%), followed by serogroups X (0.44%), A (0.39%), and W135 (0.34%). Carriage prevalence was the highest in the rural districts and in the dry season, but serogroup distribution also varied by district. A total of 29 sequence types (STs) and 51 porA-fetA combinations were identified. The dominant clone was serogroup Y, ST-4375, P1.5-1,2-2/F5-8, belonging to the ST-23 complex (47%). All serogroup A isolates were ST-2859 of the ST-5 complex with P1.20,9/F3-1. This study forms a solid basis for evaluating the impact of MenAfriVac introduction on serogroup A carriage.
authors.affiliation: Norwegian Institute of Public Health, Nydalen, 0403 Oslo, Norway.
authors.forename: Paul A
authors.initials: PA
authors.lastname: Kristiansen
authors.forename: Fabien
authors.initials: F
authors.lastname: Diomandé
authors.forename: Stanley C
authors.initials: SC
authors.lastname: Wei
authors.forename: Rasmata
authors.initials: R
authors.lastname: Ouédraogo
authors.forename: Lassana
authors.initials: L
authors.lastname: Sangaré
authors.forename: Idrissa
authors.initials: I
authors.lastname: Sanou
authors.forename: Denis
authors.initials: D
authors.lastname: Kandolo
authors.forename: Pascal
authors.initials: P
authors.lastname: Kaboré
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Clark
authors.forename: Abdoul-Salam
authors.initials: AS
authors.lastname: Ouédraogo
authors.forename: Ki Ba
authors.initials: KB
authors.lastname: Absatou
authors.forename: Charles D
authors.initials: CD
authors.lastname: Ouédraogo
authors.forename: Musa
authors.initials: M
authors.lastname: Hassan-King
authors.forename: Jennifer Dolan
authors.initials: JD
authors.lastname: Thomas
authors.forename: Cynthia
authors.initials: C
authors.lastname: Hatcher
authors.forename: Mamoudou
authors.initials: M
authors.lastname: Djingarey
authors.forename: Nancy
authors.initials: N
authors.lastname: Messonnier
authors.forename: Marie-Pierre
authors.initials: MP
authors.lastname: Préziosi
authors.forename: Marc
authors.initials: M
authors.lastname: LaForce
authors.forename: Dominique A
authors.initials: DA
authors.lastname: Caugant
mesh_terms: D000293:Adolescent; D000328:Adult; D015373:Bacterial Typing Techniques; D002050:Burkina Faso / Q000453:epidemiology; D002353:Carrier State / Q000453:epidemiology* / Q000382:microbiology; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D005838:Genotype; D006801:Humans; D007223:Infant; D008297:Male; D008589:Meningococcal Infections / Q000453:epidemiology* / Q000382:microbiology; D022401:Meningococcal Vaccines / Q000008:administration & dosage / Q000276:immunology; D058889:Molecular Typing; D058885:Multilocus Sequence Typing; D009345:Neisseria meningitidis / Q000145:classification* / Q000302:isolation & purification*; D015995:Prevalence; D012424:Rural Population; D012703:Serotyping; D014505:Urban Population; D018074:Vaccines, Conjugate / Q000008:administration & dosage / Q000276:immunology; D055815:Young Adult
chemical_list: D022401:Meningococcal Vaccines; D018074:Vaccines, Conjugate