Emergence of epidemic Neisseria meningitidis serogroup C in Niger, 2015: an analysis of national surveillance data

• Published in: The Lancet infectious diseases Vol. 16; no. 11; pp. 1288 - 1294
• Main Authors: Sidikou, Fati, Zaneidou, Maman, Alkassoum, Ibrahim, Schwartz, Stephanie, Issaka, Bassira, Obama, Ricardo, Lingani, Clement, Tate, Ashley, Ake, Flavien, Sakande, Souleymane, Ousmane, Sani, Zanguina, Jibir, Seidou, Issaka, Nzeyimana, Innocent, Mounkoro, Didier, Abodji, Oubote, Wang, Xin, Taha, Muhamed-Kheir, Moulia-Pelat, Jean Paul, Pana, Assimawe, Kadade, Goumbi, Ronveaux, Olivier, Novak, Ryan, Oukem-Boyer, Odile Ouwe Missi, Meyer, Sarah
• Format: Journal Article
• Language: English
• Published: United States Elsevier Ltd 01.11.2016; Elsevier Limited; New York, NY : Elsevier Science ; The Lancet Pub. Group, 2001
• Subjects: Epidemics; Humans; Immunization; Infectious Disease; Infectious diseases; Laboratories; Life Sciences; Mass Vaccination; Meningitis, Meningococcal - epidemiology; Meningitis, Meningococcal - microbiology; Meningitis, Meningococcal - prevention & control; Meningococcal Vaccines - administration & dosage; Meningococcal Vaccines - immunology; Microbiology and Parasitology; Neisseria meningitidis; Neisseria meningitidis - classification; Neisseria meningitidis - genetics; Neisseria meningitidis - immunology; Neisseria meningitidis - isolation & purification; Neisseria meningitidis, Serogroup C - isolation & purification; Niger - epidemiology; Population Surveillance; Real-Time Polymerase Chain Reaction; Santé publique et épidémiologie; Vaccines; Niger; Burkina Faso
• ISSN: 1473-3099; 1474-4457
• DOI: 10.1016/S1473-3099(16)30253-5

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. 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. 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. 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. 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.