Detection of the serogoups and serotypes causing bacterial meningitidis in Bangui, 2012

Abstract

Objective: The aim of this study was to identify the serogroup and serotypes causing bacterial meningitidis and to determine their prevalence in Bangui, Central African Republic.

Materials and methods: Cerebrospinal fluid (CSF) from patients with suspected meningitis were collected and tested with cell counts, Gram staining, cultures, the latex agglutination test (LAT), and real-time PCR that used specific primers and probes for S. pneumoniae, N. meningitidis, and H. influenzae. Patients were eligible if they had a CSF sample as well as information about cell counts, Gram staining, the culture, the LAT, and the PCR. Antibiotic detection disks from Bio-Rad laboratory were used to test for the presence of antibiotic activity in the CSF. An uncorrected Chi² test was used for comparisons.

Results: Of the 216 CSF samples collected, 71 were analyzed: 17 Gram stains were positive, as were 6 cultures, 15 LATs, and 33 PCRs. Among the latter, the serogroup distribution was highest for S. pneumoniae, which accounted for 82% (27/33) of the positive cases; H. influenzae type b accounted for 12% (4/33), and N. meningitidis A for 6% (2/33) positive cases. N. meningitidis No W₁₃₅, N. meningitides B, N. meningitides X, or Streptococcus C serogroups were isolated.

Conclusion: One year after the introduction of the PCV 13 vaccine, S. pneumoniae was identified as the predominant disease-causing strain. This study demonstrated the essential role of laboratory confirmation of meningitis cases to assess changes in disease epidemiology.

Keywords: Central African Republic; RT-PCR; bacterial meningitis; serogroup; serotype.