title: Predictors of immunity after a major serogroup W-135 meningococcal disease epidemic, Burkina Faso, 2002.
abstract: BACKGROUND
  The African meningitis belt undergoes recurrent epidemics caused by Neisseria meningitidis serogroup A. During 2002, Burkina Faso documented the first large serogroup W-135 (NmW-135) meningococcal disease epidemic. To understand the emergence of NmW-135, we investigated meningococcal carriage and immunity.
  
  
  METHODS
  Immediately after Burkina Faso's epidemic, we conducted a cross-sectional survey of meningococcal carriage and seroprevalence in an epidemic and a nonepidemic district. We identified predictors of elevated NmW-135 serum bactericidal activity (SBA), a functional correlate of protection, using multivariate logistic regression.
  
  
  RESULTS
  The NmW-135 carriage rate was 25.2% in the epidemic district and 3.4% in the nonepidemic district (P<.0001). Compared with residents of the nonepidemic district, those of the epidemic district had higher geometric mean titers of NmW-135 SBA (P<.0001). NmW-135 SBA titers>or=1:8, an estimated protective threshold, were observed in 60.4% and 34.0% of residents of the epidemic and nonepidemic district, respectively (P=.0002). In a multivariate model, current NmW-135 carriage, age, and residence in the epidemic district were independent predictors of having an NmW-135 SBA titer>or=1:8.
  
  
  CONCLUSIONS
  Extensive NmW-135 carriage and transmission in the epidemic area caused residents to acquire natural immunity. Serial carriage and seroprevalence surveys could establish the duration of immunity in the population. The persistent circulation of NmW-135 underscores the potential for periodic NmW-135 epidemics in Africa.
authors.affiliation: National Center for Infectious Diseases and Epidemiology Program Office, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA. pgr4@cdc.gov
authors.forename: Pratima L
authors.initials: PL
authors.lastname: Raghunathan
authors.forename: Joshua D
authors.initials: JD
authors.lastname: Jones
authors.forename: Sylvestre R M
authors.initials: SR
authors.lastname: Tiendrebéogo
authors.forename: Idrissa
authors.initials: I
authors.lastname: Sanou
authors.forename: Lassana
authors.initials: L
authors.lastname: Sangaré
authors.forename: Seni
authors.initials: S
authors.lastname: Kouanda
authors.forename: Moumouni
authors.initials: M
authors.lastname: Dabal
authors.forename: Clement
authors.initials: C
authors.lastname: Lingani
authors.forename: Cheryl M
authors.initials: CM
authors.lastname: Elie
authors.forename: Scott
authors.initials: S
authors.lastname: Johnson
authors.forename: Mary
authors.initials: M
authors.lastname: Ari
authors.forename: Joseph
authors.initials: J
authors.lastname: Martinez
authors.forename: Julie
authors.initials: J
authors.lastname: Chatt
authors.forename: Kassim
authors.initials: K
authors.lastname: Sidibe
authors.forename: Susanna
authors.initials: S
authors.lastname: Schmink
authors.forename: Leonard W
authors.initials: LW
authors.lastname: Mayer
authors.forename: M Kader
authors.initials: MK
authors.lastname: Kondé
authors.forename: Mamoudou H
authors.initials: MH
authors.lastname: Djingarey
authors.forename: Tanja
authors.initials: T
authors.lastname: Popovic
authors.forename: Brian D
authors.initials: BD
authors.lastname: Plikaytis
authors.forename: George M
authors.initials: GM
authors.lastname: Carlone
authors.forename: Nancy
authors.initials: N
authors.lastname: Rosenstein
authors.forename: Montse
authors.initials: M
authors.lastname: Soriano-Gabarró
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000907:Antibodies, Bacterial / Q000097:blood; D002050:Burkina Faso / Q000453:epidemiology; D002353:Carrier State / Q000382:microbiology; D002648:Child; D002675:Child, Preschool; D004196:Disease Outbreaks; D005260:Female; D005843:Geography; D006801:Humans; D016015:Logistic Models; D008297:Male; D008585:Meningitis, Meningococcal / Q000453:epidemiology* / Q000276:immunology* / Q000382:microbiology; D008589:Meningococcal Infections / Q000453:epidemiology* / Q000276:immunology* / Q000382:microbiology; D015999:Multivariate Analysis; D038582:Neisseria meningitidis, Serogroup W-135 / Q000276:immunology*; D016036:Seroepidemiologic Studies
chemical_list: D000907:Antibodies, Bacterial