Distribution of Streptococcus pneumoniae serotypes in nasopharyngeal carriage and in invasive pneumococcal disease in Sao Paulo, Brazil.

To determine whether serotypes of S. pneumoniae isolated from the nasopharynx (NP) are representative of data from patients with invasive disease, we collected NP swab specimens from children, between 3 months and 5 years and obtained data from 105 children hospitalized with invasive disease. The prevalence of penicillin nonsusceptible strains in the NP carriage and invasive disease group was 16.4% and 17%, respectively, in the first period and 42% and 45% in the second period. The serotypes 23F, 6A, 14 and 19F were the most common in the NP study and 14, 1, 5 and 6B were the most common in invasive infections.