Pediatric Bacterial Meningitis Surveillance in Niger: Increased Importance of Neisseria meningitidis Serogroup C, and a Decrease in Streptococcus pneumoniae Following 13-Valent Pneumococcal Conjugate Vaccine Introduction.

BACKGROUND: Meningitis is endemic in Niger. Haemophilus influenzae type b (Hib) vaccine and the 13-valent pneumococcal conjugate vaccine (PCV13) were introduced in 2008 and 2014, respectively. Vaccination campaign against Neisseria meningitidis serogroup A was carried out in 2010-2011. We evaluated changes in pathogen distribution using data from hospital-based surveillance in Niger from 2010 through 2016. METHODS: Cerebrospinal fluid (CSF) specimens from children <5 years old with suspected meningitis were tested to detect vaccine-preventable bacterial pathogens. Confirmatory identification and serotyping/grouping of Streptococcus pneumoniae, N. meningitidis, and H. influenzae were done. Antimicrobial susceptibility testing and whole genome sequencing were performed on S. pneumoniae isolates. RESULTS: The surveillance included 2580 patients with suspected meningitis, of whom 80.8% (2085/2580) had CSF collected. Bacterial meningitis was confirmed in 273 patients: 48% (131/273) was N. meningitidis, 45% (123/273) S. pneumoniae, and 7% (19/273) H. influenzae. Streptococcus pneumoniae meningitis decreased from 34 in 2014, to 16 in 2016. PCV13 serotypes made up 88% (7/8) of S. pneumoniae meningitis prevaccination and 20% (5/20) postvaccination. Neisseria meningitidis serogroup C (NmC) was responsible for 59% (10/17) of serogrouped N. meningitidis meningitis. Hib caused 67% (2/3) of the H. influenzae meningitis isolates serotyped. Penicillin resistance was found in 16% (4/25) of S. pneumoniae isolates. Sequence type 217 was the most common lineage among S. pneumoniae isolates. CONCLUSIONS: Neisseria meningitidis and S. pneumoniae remain important causes of meningitis in children in Niger. The decline in the numbers of S. pneumoniae meningitis post-PCV13 is encouraging and should continue to be monitored. NmC is the predominant serogroup causing N. meningitidis meningitis.

Prevalence of Bordetella infection in a hospital setting in niamey, niger.

Bordetella pertussis still poses an important health threat in developing countries. In Niger, notified pertussis cases are few despite the low diphtheria-tetanus-pertussis/pentavalent vaccine coverage. We aimed to estimate the prevalence of B. pertussis in children aged <5 years consulting at a pediatric ward. A 5-month study in 2011 recruited 342 children with respiratory symptoms at the National Hospital of Niamey. Nasopharyngeal aspirates were tested by culture and real-time polymerase chain reaction. Overall, 34 (11.2%) of the 305 available nasopharyngeal aspirates tested by real-time polymerase chain reaction were positive for a Bordetella spp., with an estimated prevalence of 8.2 cases per 1000 children aged <5. None was notified to the surveillance network. A single specimen was positive on culture. This study, the first to provide laboratory-confirmed data on pertussis in Niger, highlights the need to sensitize health care personnel to actively notify clinical cases and to integrate laboratory diagnosis in the existing surveillance system.