title: Emergence of epidemic Neisseria meningitidis serogroup C in Niger, 2015: an analysis of national surveillance data.
abstract: BACKGROUND
  To combat Neisseria meningitidis serogroup A epidemics in the meningitis belt of sub-Saharan Africa, a meningococcal serogroup A conjugate vaccine (MACV) has been progressively rolled out since 2010. We report the first meningitis epidemic in Niger since the nationwide introduction of MACV.
  
  
  METHODS
  We compiled and analysed nationwide case-based meningitis surveillance data in Niger. Cases were confirmed by culture or direct real-time PCR, or both, of cerebrospinal fluid specimens, and whole-genome sequencing was used to characterise isolates. Information on vaccination campaigns was collected by the Niger Ministry of Health and WHO.
  
  
  RESULTS
  From Jan 1 to June 30, 2015, 9367 suspected meningitis cases and 549 deaths were reported in Niger. Among 4301 cerebrospinal fluid specimens tested, 1603 (37·3%) were positive for a bacterial pathogen, including 1147 (71·5%) that were positive for N meningitidis serogroup C (NmC). Whole-genome sequencing of 77 NmC isolates revealed the strain to be ST-10217. Although vaccination campaigns were limited in scope because of a global vaccine shortage, 1·4 million people were vaccinated from March to June, 2015.
  
  
  CONCLUSIONS
  This epidemic represents the largest global NmC outbreak so far and shows the continued threat of N meningitidis in sub-Saharan Africa. The risk of further regional expansion of this novel clone highlights the need for continued strengthening of case-based surveillance. The availability of an affordable, multivalent conjugate vaccine may be important in future epidemic response.
  
  
  BACKGROUND
  MenAfriNet consortium, a partnership between the US Centers for Disease Control and Prevention, WHO, and Agence de Médecine Preventive, through a grant from the Bill & Melinda Gates Foundation.
authors: Centre de Recherche Médicale et Sanitaire (CERMES), Ministry of Public Health, Institut Pasteur International Network, Niamey, Niger.
authors: Fati
authors: F
authors: Sidikou
authors: Direction de la Surveillance et Riposte aux Epidémies, Ministry of Health, Niamey, Niger.
authors: Maman
authors: M
authors: Zaneidou
authors: Direction de la Surveillance et Riposte aux Epidémies, Ministry of Health, Niamey, Niger.
authors: Ibrahim
authors: I
authors: Alkassoum
authors: Meningitis and Vaccine Preventable Diseases Branch, National Center for Immunization and Respiratory Diseases, US Centers for Disease Control and Prevention, Atlanta, GA, USA.
authors: Stephanie
authors: S
authors: Schwartz
authors: Centre de Recherche Médicale et Sanitaire (CERMES), Ministry of Public Health, Institut Pasteur International Network, Niamey, Niger.
authors: Bassira
authors: B
authors: Issaka
authors: World Health Organization-Niger, Niamey, Niger.
authors: Ricardo
authors: R
authors: Obama
authors: World Health Organization Intercountry Support Team for West Africa, Ouagadougou, Burkina Faso.
authors: Clement
authors: C
authors: Lingani
authors: Meningitis and Vaccine Preventable Diseases Branch, National Center for Immunization and Respiratory Diseases, US Centers for Disease Control and Prevention, Atlanta, GA, USA.
authors: Ashley
authors: A
authors: Tate
authors: Davycas Consulting, Gounghin Petit-Paris, Ouagadougou, Burkina Faso.
authors: Flavien
authors: F
authors: Ake
authors: Agence de Médecine Préventive-Ouagadougou, Ouagadougou, Burkina Faso.
authors: Souleymane
authors: S
authors: Sakande
authors: Centre de Recherche Médicale et Sanitaire (CERMES), Ministry of Public Health, Institut Pasteur International Network, Niamey, Niger.
authors: Sani
authors: S
authors: Ousmane
authors: Centre de Recherche Médicale et Sanitaire (CERMES), Ministry of Public Health, Institut Pasteur International Network, Niamey, Niger.
authors: Jibir
authors: J
authors: Zanguina
authors: Centre de Recherche Médicale et Sanitaire (CERMES), Ministry of Public Health, Institut Pasteur International Network, Niamey, Niger.
authors: Issaka
authors: I
authors: Seidou
authors: World Health Organization-Niger, Niamey, Niger.
authors: Innocent
authors: I
authors: Nzeyimana
authors: Agence de Médecine Préventive-Togo, Dapaong, Togo.
authors: Didier
authors: D
authors: Mounkoro
authors: Agence de Médecine Préventive-Togo, Dapaong, Togo.
authors: Oubote
authors: O
authors: Abodji
authors: Meningitis and Vaccine Preventable Diseases Branch, National Center for Immunization and Respiratory Diseases, US Centers for Disease Control and Prevention, Atlanta, GA, USA.
authors: Xin
authors: X
authors: Wang
authors: Institut Pasteur, Paris, France.
authors: Muhamed-Kheir
authors: MK
authors: Taha
authors: Centre de Recherche Médicale et Sanitaire (CERMES), Ministry of Public Health, Institut Pasteur International Network, Niamey, Niger.
authors: Jean Paul
authors: JP
authors: Moulia-Pelat
authors: World Health Organization-Niger, Niamey, Niger.
authors: Assimawe
authors: A
authors: Pana
authors: Direction de la Surveillance et Riposte aux Epidémies, Ministry of Health, Niamey, Niger.
authors: Goumbi
authors: G
authors: Kadade
authors: World Health Organization, Geneva, Switzerland.
authors: Olivier
authors: O
authors: Ronveaux
authors: Meningitis and Vaccine Preventable Diseases Branch, National Center for Immunization and Respiratory Diseases, US Centers for Disease Control and Prevention, Atlanta, GA, USA.
authors: Ryan
authors: R
authors: Novak
authors: Centre de Recherche Médicale et Sanitaire (CERMES), Ministry of Public Health, Institut Pasteur International Network, Niamey, Niger.
authors: Odile Ouwe Missi
authors: OOM
authors: Oukem-Boyer
authors: Meningitis and Vaccine Preventable Diseases Branch, National Center for Immunization and Respiratory Diseases, US Centers for Disease Control and Prevention, Atlanta, GA, USA. Electronic address: SMeyer@cdc.gov.
authors: Sarah
authors: S
authors: Meyer
mesh_terms: D058872:Epidemics; D006801:Humans; D032541:Mass Vaccination; D008585:Meningitis, Meningococcal / Q000453:epidemiology* / Q000382:microbiology / Q000517:prevention & control; D022401:Meningococcal Vaccines / Q000008:administration & dosage* / Q000276:immunology; D009345:Neisseria meningitidis / Q000145:classification / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification*; D038542:Neisseria meningitidis, Serogroup C / Q000302:isolation & purification*; D009548:Niger / Q000453:epidemiology; D011159:Population Surveillance; D060888:Real-Time Polymerase Chain Reaction
chemical_list: D022401:Meningococcal Vaccines