Phylogenetic relationships and regional spread of meningococcal strains in the meningitis belt, 2011–2016Research in context
Nadav Topaz,
Dominique A. Caugant,
Muhamed-Kheir Taha,
Ola Brønstad Brynildsrud,
Nadia Debech,
Eva Hong,
Ala-Eddine Deghmane,
Rasmata Ouédraogo,
Sani Ousmane,
Kadidja Gamougame,
Berthe-Marie Njanpop-Lafourcade,
Seydou Diarra,
LeAnne M. Fox,
Xin Wang
Affiliations
Nadav Topaz
Meningitis and Vaccine Preventable Diseases Branch, Division of Bacterial Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, United States
Dominique A. Caugant
Division for Infection Control and Environmental Health, Norwegian Institute of Public Health, Oslo, Norway; Department of Community Medicine and Global Health, Faculty of Medicine, University of Oslo, Oslo, Norway
Muhamed-Kheir Taha
Institut Pasteur, Invasive Bacterial Infections Unit and WHO collaborating Centre for meningitis, Paris, France
Ola Brønstad Brynildsrud
Division for Infection Control and Environmental Health, Norwegian Institute of Public Health, Oslo, Norway
Nadia Debech
Division for Infection Control and Environmental Health, Norwegian Institute of Public Health, Oslo, Norway
Eva Hong
Institut Pasteur, Invasive Bacterial Infections Unit and WHO collaborating Centre for meningitis, Paris, France
Ala-Eddine Deghmane
Institut Pasteur, Invasive Bacterial Infections Unit and WHO collaborating Centre for meningitis, Paris, France
Rasmata Ouédraogo
Centre Hospitalier Universitaire Pédiatrique Charles de Gaulle, Ouagadougou 01, Burkina Faso
Sani Ousmane
Centre de Recherche Médicale et Sanitaire, CERMES, Niamey, Niger
Kadidja Gamougame
Centre de Support en Santé International, N'Djamena, Chad
Berthe-Marie Njanpop-Lafourcade
Agence de Médecine Préventive, Paris, France
Seydou Diarra
Institut National de Recherche en Santé Publique, Bamako 00223, Mali
LeAnne M. Fox
Meningitis and Vaccine Preventable Diseases Branch, Division of Bacterial Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, United States
Xin Wang
Meningitis and Vaccine Preventable Diseases Branch, Division of Bacterial Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, United States; Corresponding author at: Meningitis and Vaccine Preventable Diseases Branch, Division of Bacterial Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, 1600 Clifton Rd NE, MS D-11, Atlanta, GA 30329, United States.
Background: Historically, the major cause of meningococcal epidemics in the meningitis belt of sub-Saharan Africa has been Neisseria meningitidis serogroup A (NmA), but the incidence has been substantially reduced since the introduction of a serogroup A conjugate vaccine starting in 2010. We performed whole-genome sequencing on isolates collected post-2010 to assess their phylogenetic relationships and inter-country transmission. Methods: A total of 716 invasive meningococcal isolates collected between 2011 and 2016 from 11 meningitis belt countries were whole-genome sequenced for molecular characterization by the three WHO Collaborating Centers for Meningitis. Findings: We identified three previously-reported clonal complexes (CC): CC11 (n = 434), CC181 (n = 62) and CC5 (n = 90) primarily associated with NmW, NmX, and NmA, respectively, and an emerging CC10217 (n = 126) associated with NmC. CC11 expanded throughout the meningitis belt independent of the 2000 Hajj outbreak strain, with isolates from Central African countries forming a distinct sub-lineage within this expansion. Two major sub-lineages were identified for CC181 isolates, one mainly expanding in West African countries and the other found in Chad. CC10217 isolates from the large outbreaks in Nigeria and Niger were more closely related than those from the few cases in Mali and Burkina Faso. Interpretations: Whole-genome based phylogenies revealed geographically distinct strain circulation as well as inter-country transmission events. Our results stress the importance of continued meningococcal molecular surveillance in the region, as well as the development of an affordable vaccine targeting these strains. Fund: Meningitis Research Foundation; CDC's Office of Advanced Molecular Detection; GAVI, the Vaccine Alliance. Keywords: Meningitis, Meningitis belt, Invasive meningococcal disease, Phylogenetics, Neisseria meningitidis
