matériau (3) enfant (3) Mexique (3) Children (3) Children (3) Carriers (3) Methods (2) Streptococcus pneumoniae (2) Standards (2) Penicillin (2) Methods (2) Susceptibility (2) Standards (2) Infections (2) résistance (2) gaz (1) effet (1) densité (1) public (1) Density (1) Degrees (1) Social networks (1) Values (1) Vaccines (1) Streptococcus pyogenes (1) Streptococcus (1) Proportion (1) Nasopharynx (1) Interpersonal relations (1) Gas (1)