title: Methods for identifying Neisseria meningitidis carriers: a multi-center study in the African meningitis belt.
abstract: OBJECTIVE
  Detection of meningococcal carriers is key to understanding the epidemiology of Neisseria meningitidis, yet no gold standard has been established. Here, we directly compare two methods for collecting pharyngeal swabs to identify meningococcal carriers.
  
  
  METHODS
  We conducted cross-sectional surveys of schoolchildren at multiple sites in Africa to compare swabbing the posterior pharynx behind the uvula (U) to swabbing the posterior pharynx behind the uvula plus one tonsil (T). Swabs were cultured immediately and analyzed using molecular methods.
  
  
  RESULTS
  One thousand and six paired swab samples collected from schoolchildren in four countries were analyzed. Prevalence of meningococcal carriage was 6.9% (95% CI: 5.4-8.6%) based on the results from both swabs, but the observed prevalence was lower based on one swab type alone. Prevalence based on the T swab or the U swab alone was similar (5.2% (95% CI: 3.8-6.7%) versus 4.9% (95% CI: 3.6-6.4%) respectively (p=0.6)). The concordance between the two methods was 96.3% and the kappa was 0.61 (95% CI: 0.50-0.73), indicating good agreement.
  
  
  CONCLUSIONS
  These two commonly used methods for collecting pharyngeal swabs provide consistent estimates of the prevalence of carriage, but both methods misclassified carriers to some degree, leading to underestimates of the prevalence.
authors.affiliation: Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey, United States of America ; Research and Policy for Infectious Disease Dynamics, Fogarty International Center, National Institutes of Health, Bethesda, Maryland, United States of America ; Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America.
authors.forename: Nicole E
authors.initials: NE
authors.lastname: Basta
authors.forename: James M
authors.initials: JM
authors.lastname: Stuart
authors.forename: Maria C
authors.initials: MC
authors.lastname: Nascimento
authors.forename: Olivier
authors.initials: O
authors.lastname: Manigart
authors.forename: Caroline
authors.initials: C
authors.lastname: Trotter
authors.forename: Musa
authors.initials: M
authors.lastname: Hassan-King
authors.forename: Daniel
authors.initials: D
authors.lastname: Chandramohan
authors.forename: Samba O
authors.initials: SO
authors.lastname: Sow
authors.forename: Abdoulaye
authors.initials: A
authors.lastname: Berthe
authors.forename: Ahmed
authors.initials: A
authors.lastname: Bedru
authors.forename: Yenenesh K
authors.initials: YK
authors.lastname: Tekletsion
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Collard
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Jusot
authors.forename: Aldiouma
authors.initials: A
authors.lastname: Diallo
authors.forename: Hubert
authors.initials: H
authors.lastname: Basséne
authors.forename: Doumagoum M
authors.initials: DM
authors.lastname: Daugla
authors.forename: Khadidja
authors.initials: K
authors.lastname: Gamougam
authors.forename: Abraham
authors.initials: A
authors.lastname: Hodgson
authors.forename: Abudulai A
authors.initials: AA
authors.lastname: Forgor
authors.forename: Babatunji A
authors.initials: BA
authors.lastname: Omotara
authors.forename: Galadima B
authors.initials: GB
authors.lastname: Gadzama
authors.forename: Eleanor R
authors.initials: ER
authors.lastname: Watkins
authors.forename: Lisa S
authors.initials: LS
authors.lastname: Rebbetts
authors.forename: Kanny
authors.initials: K
authors.lastname: Diallo
authors.forename: Noel S
authors.initials: NS
authors.lastname: Weiss
authors.forename: M Elizabeth
authors.initials: ME
authors.lastname: Halloran
authors.forename: Martin C J
authors.initials: MC
authors.lastname: Maiden
authors.forename: Brian
authors.initials: B
authors.lastname: Greenwood
mesh_terms: D000293:Adolescent; D000354:Africa, Western / Q000453:epidemiology; D002353:Carrier State / Q000453:epidemiology*; D002648:Child; D003430:Cross-Sectional Studies; D005002:Ethiopia / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D008589:Meningococcal Infections / Q000453:epidemiology* / Q000635:transmission; D009305:Nasopharynx / Q000382:microbiology; D009345:Neisseria meningitidis / Q000302:isolation & purification*; D014066:Palatine Tonsil / Q000382:microbiology; D015995:Prevalence; D013048:Specimen Handling / Q000379:methods*