title: Epidemiological and molecular characteristics of a highly lethal pneumococcal meningitis epidemic in Burkina Faso.
abstract: 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.
authors.affiliation: Centre Muraz, Bobo-Dioulasso, Burkina Faso.
authors.forename: Seydou
authors.initials: S
authors.lastname: Yaro
authors.forename: Mathilde
authors.initials: M
authors.lastname: Lourd
authors.forename: Yves
authors.initials: Y
authors.lastname: Traoré
authors.forename: Berthe-Marie
authors.initials: BM
authors.lastname: Njanpop-Lafourcade
authors.forename: Adrien
authors.initials: A
authors.lastname: Sawadogo
authors.forename: Lassana
authors.initials: L
authors.lastname: Sangare
authors.forename: Alain
authors.initials: A
authors.lastname: Hien
authors.forename: Macaire S
authors.initials: MS
authors.lastname: Ouedraogo
authors.forename: Oumarou
authors.initials: O
authors.lastname: Sanou
authors.forename: Isabelle
authors.initials: I
authors.lastname: Parent du Châtelet
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Koeck
authors.forename: Bradford D
authors.initials: BD
authors.lastname: Gessner
mesh_terms: 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