Epidemiological and molecular characteristics of a highly lethal pneumococcal meningitis epidemic in Burkina Faso.
BACKGROUND
Public health and clinical strategies for meningitis epidemics in sub-Saharan Africa usually assume that Neisseria meningitidis infection causes most disease.


METHODS
During 24 months from 2002 to 2005, we collected clinical and laboratory information for suspected acute bacterial meningitis cases from 3 districts in Burkina Faso. Streptococcus pneumoniae was identified by culture, polymerase chain reaction, or antigen detection in cerebrospinal fluid. Pneumococcal genotyping was performed on strains using multilocus variable-number tandem repeat typing and multilocus sequence typing.


RESULTS
Samples of cerebrospinal fluid were collected from 1686 persons; 249 (15%) had S. pneumoniae identified (annual incidence, 14 cases per 100,000 persons). Of these patients, 115 (46%) died, making S. pneumoniae the most commonly identified organism and responsible for two-thirds of deaths due to bacterial meningitis. During the meningitis epidemic season, an average of 38 cases of S. pneumoniae infection were identified each month, compared with an average of 8.7 cases during other months. Of 48 pneumococci that were tested, 21 (44%) were identified as serotype 1, and the remaining 27 (56%) were identified as 15 different serogroups and/or serotypes. Both serotype 1 and other serogroups and/or serotypes were seasonal. The genotypes of serotype 1 isolates were closely related but diversified over the study period and were similar to, but not identical to, the predominant genotypes found previously in Ghana.


CONCLUSIONS
Intervention strategies during the epidemic season in Burkina Faso (and perhaps elsewhere) must now account for pneumococcal meningitis occurring in an epidemic pattern similar to meningococcal meningitis. Although a serotype 1 clone was commonly isolated, over half of the cases were caused by other serogroups and/or serotypes, and genetic diversification increased over a relatively short period.
Yaro
Seydou
S
Centre Muraz, Bobo-Dioulasso, Burkina Faso.
Lourd
Mathilde
M
Traoré
Yves
Y
Njanpop-Lafourcade
Berthe-Marie
BM
Sawadogo
Adrien
A
Sangare
Lassana
L
Hien
Alain
A
Ouedraogo
Macaire S
MS
Sanou
Oumarou
O
Parent du Châtelet
Isabelle
I
Koeck
Jean-Louis
JL
Gessner
Bradford D
BD
D000293:Adolescent; D000328:Adult; D000368:Aged; D002050:Burkina Faso / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D004196:Disease Outbreaks; D024881:Drug Resistance, Bacterial; D005838:Genotype; D006801:Humans; D007223:Infant; D008586:Meningitis, Pneumococcal / Q000453:epidemiology* / Q000382:microbiology / Q000401:mortality; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D010802:Phylogeny; D012621:Seasons; D012703:Serotyping; D013296:Streptococcus pneumoniae / Q000145:classification* / Q000187:drug effects / Q000235:genetics