title: The Establishment and Diversification of Epidemic-Associated Serogroup W Meningococcus in the African Meningitis Belt, 1994 to 2012.
abstract: Epidemics of invasive meningococcal disease (IMD) caused by meningococcal serogroup A have been eliminated from the sub-Saharan African so-called "meningitis belt" by the meningococcal A conjugate vaccine (MACV), and yet, other serogroups continue to cause epidemics.Neisseria meningitidisserogroup W remains a major cause of disease in the region, with most isolates belonging to clonal complex 11 (CC11). Here, the genetic variation within and between epidemic-associated strains was assessed by sequencing the genomes of 92N. meningitidisserogroup W isolates collected between 1994 and 2012 from both sporadic and epidemic IMD cases, 85 being from selected meningitis belt countries. The sequenced isolates belonged to either CC175 (n= 9) or CC11 (n= 83). The CC11N. meningitidisserogroup W isolates belonged to a single lineage comprising four major phylogenetic subclades. Separate CC11N. meningitidisserogroup W subclades were associated with the 2002 and 2012 Burkina Faso epidemics. The subclade associated with the 2012 epidemic included isolates found in Burkina Faso and Mali during 2011 and 2012, which descended from a strain very similar to the Hajj (Islamic pilgrimage to Mecca)-related Saudi Arabian outbreak strain from 2000. The phylogeny of isolates from 2012 reflected their geographic origin within Burkina Faso, with isolates from the Malian border region being closely related to the isolates from Mali. Evidence of ongoing evolution, international transmission, and strain replacement stresses the importance of maintainingN. meningitidissurveillance in Africa following the MACV implementation.IMPORTANCEMeningococcal disease (meningitis and bloodstream infections) threatens millions of people across the meningitis belt of sub-Saharan Africa. A vaccine introduced in 2010 protects against Africa's then-most common cause of meningococcal disease,N. meningitidisserogroup A. However, other serogroups continue to cause epidemics in the region-including serogroup W. The rapid identification of strains that have been associated with prior outbreaks can improve the assessment of outbreak risk and enable timely preparation of public health responses, including vaccination. Phylogenetic analysis of newly sequenced serogroup W strains isolated from 1994 to 2012 identified two groups of strains linked to large epidemics in Burkina Faso, one being descended from a strain that caused an outbreak during the Hajj pilgrimage in 2000. We find that applying whole-genome sequencing to meningococcal disease surveillance collections improves the discrimination among strains, even within a single nation-wide epidemic, which can be used to better understand pathogen spread.
authors.affiliation: Meningitis and Vaccine Preventable Disease Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
authors.forename: Adam C
authors.identifier: 0000-0001-7185-591X
authors.initials: AC
authors.lastname: Retchless
authors.affiliation: Meningitis and Vaccine Preventable Disease Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
authors.forename: Fang
authors.initials: F
authors.lastname: Hu
authors.affiliation: Centre Hospitalier Universitaire Sanou Sourou, Bobo-Dioulasso, Burkina Faso.
authors.forename: Abdoul-Salam
authors.initials: AS
authors.lastname: Ouédraogo
authors.affiliation: Institut National de Recherche en Santé Publique, Bamako, Mali.
authors.forename: Seydou
authors.initials: S
authors.lastname: Diarra
authors.affiliation: Biotechnology Core Facility Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
authors.forename: Kristen
authors.initials: K
authors.lastname: Knipe
authors.affiliation: Biotechnology Core Facility Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
authors.forename: Mili
authors.initials: M
authors.lastname: Sheth
authors.affiliation: Biotechnology Core Facility Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
authors.forename: Lori A
authors.initials: LA
authors.lastname: Rowe
authors.affiliation: Centre Hospitalier Universitaire Yalgado Ouédraogo, Ouagadougou, Burkina Faso.
authors.forename: Lassana
authors.initials: L
authors.lastname: Sangaré
authors.affiliation: Laboratoire National de Santé Public, Ouagadougou, Burkina Faso.
authors.forename: Absetou
authors.initials: A
authors.lastname: Ky Ba
authors.affiliation: Centre Muraz, Bobo-Dioulasso, Burkina Faso.
authors.forename: Soumeya
authors.initials: S
authors.lastname: Ouangraoua
authors.affiliation: Biotechnology Core Facility Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
authors.forename: Dhwani
authors.initials: D
authors.lastname: Batra
authors.affiliation: Meningitis and Vaccine Preventable Disease Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
authors.forename: Ryan T
authors.initials: RT
authors.lastname: Novak
authors.affiliation: Centre Hospitalier Universitaire Pédiatrique Charles de Gaulle, Ouagadougou, Burkina Faso.
authors.forename: Rasmata
authors.initials: R
authors.lastname: Ouédraogo Traoré
authors.affiliation: Meningitis and Vaccine Preventable Disease Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
authors.forename: Xin
authors.initials: X
authors.lastname: Wang
keywords: Africa; Neisseria meningitidis; disease outbreaks; epidemiology; evolution; meningitis; meningococcus