7.
An outbreak of serotype 1 Streptococcus pneumoniae meningitis in northern Ghana
with features that are characteristic of Neisseria meningitidis meningitis
epidemics.
Leimkugel J,
Adams Forgor A,
Gagneux S,
Pfluger V,
Flierl C,
Awine E,
Naegeli M,
Dangy JP,
Smith T,
Hodgson A,
Pluschke G.
J Infect Dis. 2005 Jul 15; 192(2): 192-9. Epub 2005 Jun 10.
The Kassena-Nankana District
(KND) of northern Ghana lies in the African meningitis belt, where epidemics of
bacterial meningitis have been reoccurring every 8
12
years. These epidemics are generally caused by Neisseria meningitidis, an
organism that is considered to be uniquely capable of causing meningitis
epidemics.Methods. We recruited all patients with suspected meningitis in
the KND between 1998 and 2003. Cerebrospinal fluid samples were collected and
analyzed by standard microbiological techniques. Bacterial isolates were
subjected to serotyping, multilocus sequence typing (MLST), and
antibiotic-resistance testing.Results. A continual increase in the incidence
of pneumococcal meningitis was observed from 2000 to 2003. This outbreak
exhibited strong seasonality, a broad host age range, and clonal dominance, all
of which are characteristic of meningococcal meningitis epidemics in the African
meningitis belt. The case-fatality rate for pneumococcal meningitis was 44.4%;
the majority of pneumococcal isolates were antibiotic sensitive and expressed
the serotype 1 capsule. MLST revealed that these isolates belonged to a clonal
complex dominated by sequence type (ST) 217 and its 2 single-locus variants,
ST303 and ST612.Conclusions. The S. pneumoniae ST217 clonal complex
represents a hypervirulent lineage with a high propensity to cause meningitis,
and our results suggest that this lineage might have the potential to cause an
epidemic. Serotype 1 is not included in the currently licensed pediatric
heptavalent pneumococcal vaccine. Mass vaccination with a less complex conjugate
vaccine that targets hypervirulent serotypes should, therefore, be considered.