Molecular Epidemiology of Streptococcus Pyogenes Among Children in Bamako, Mali
Condition: Streptococcus Group A
Study type: Observational

Summary: 
      The purpose of this study is to learn more about sore throats caused by the germ Group A
      Streptococcus (GAS) or "Strep". When "Strep" causes a sore throat, it can be treated with
      medicines called antibiotics. However, if not treated, it can lead to heart problems and
      other serious diseases. This study will identify the different types of "Strep" that are
      present in children with sore throats. Researchers will check children with sore throats at
      least twice weekly among a group of approximately 12,000 children. Study participants will
      include children, ages 5-16, attending the public elementary schools in Djikoroni-Sébénikoro,
      a low income community in Bamako, Mali. Throat swabs will be obtained and free treatment is
      available when a child enrolled in the group complains of a sore throat. The information from
      this study may help make a vaccine to prevent "Strep" infection in Malian children. Children
      may participate for the 3 year duration of the study.
    

Detailed description: 
      Data on the epidemiology of group A streptococci (GAS) infection in developing countries is
      limited. Available publications suggest that not only is disease prevalent, but severe
      manifestations continue to occur at a high rate. Several promising GAS vaccine candidates are
      in pre-clinical and clinical development. One approach that has entered clinical trial is the
      use of a multivalent recombinant fusion peptide vaccine containing amino-terminal M protein
      fragments. In animal models, these M-protein type-specific epitopes induce protective opsonic
      antibodies that do not cross-react with human tissues. If type-specific vaccines are to be
      used in developing countries, then the molecular epidemiology of GAS in these settings must
      be better characterized. The primary objective of this study is to identify the genotypes
      (emm type or sub-type) of GAS isolated from 5 to 16 year old schoolchildren with pharyngitis
      living in a poor urban community in Bamako, Mali. The secondary objectives are: to
      characterize the molecular epidemiology of GAS pharyngitis among Malian schoolchildren by
      determining the distribution of genotypes according to age in years, year of study, and
      season (cold or dry); to estimate the incidence of GAS pharyngitis among 5 to 16 year old
      schoolchildren living in a poor urban community in Bamako, Mali overall and by age, gender,
      year of study, and season; and to describe the clinical features of GAS pharyngitis among the
      Malian schoolchildren. Surveillance for pharyngitis will be conducted at least twice weekly
      among a cohort of approximately 12,000 children, ages 5-16, attending the four public
      elementary schools in Djikoroni-para-Sébénikoro, a low-income community in Bamako, Mali.
      Throat swabs will be obtained when a child enrolled in the cohort complains of a sore throat.
      GAS isolated from the swabs will be characterized by emm typing. The primary endpoint of the
      study is the proportion of each emm-type among children with GAS pharyngitis. The secondary
      endpoints include the following: the proportion of each emm-type among children with GAS
      pharyngitis overall and according to age in years, year of study, and season (cold or dry);
      the proportion of children with pharyngitis from whom GAS is isolated; the minimal incidence
      of GAS pharyngitis per 100,000 children in the catchment area of Djikoroni-para-Sébénikoro
      overall and according to: age in years, gender, year of study, and season (cold or dry); the
      incidence density (number of cases per children-weeks of follow up) of GAS pharyngitis among
      enrolled school children overall and according to: age in years, year of study, and season
      (cold or dry); and the proportion of children with GAS pharyngitis who experience symptoms
      such as fever, exudative pharyngitis, tender cervical adenopathy, or scarletiniform rash,
      overall and by age in years. It is clear that GAS is an important worldwide pathogen and that
      it has been understudied in much of the developing world. Given the early successes of
      multivalent M type-specific vaccines, investigations of the molecular epidemiology
      delineating the distribution of the emm-types of the organism associated with pharyngitis
      (and therefore presumably acute rheumatic fever) are crucial for designing a vaccine that has
      utility in preventing rheumatic heart disease and other GAS disease in the developing world.
      The current protocol is intended to provide data to address these goals.
    

Observational model: Cohort
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        5-16 year old children with complaints consistent with pharyngitis attending 4 public
        schools in Bamako, Mali.
      
Biospecimen description: 
      GAS isolates.
    
Keywords: Pharyngitis, Mali, Group A Streptococcus, Children