Clonal distribution of invasive pneumococcal isolates from children and selected adults in the United States prior to 7-valent conjugate vaccine introduction

Theseven-valent pneumococcal conjugated polysaccharide vaccine PC7V was licensed for use among children in 2000. Since 90 serotypes of pneumococci exist, an increase in nonvaccine serotypes could occur through immune selection for capsular type switching. Eleven hundred sixty-eight invasive isolates (24 serotypes), recovered primarily from pediatric patients (855 isolates = 73%) and 22 reference strains of known multilocus sequence types (STs) were subjected to macrorestriction profiling (pulsed-field gel electrophoresis [PFGE]). The correlation of 187 ST results (including 49 newly discovered STs) with the PFGE data assigned 1,042 (89.2%) study isolates to 46 defined clonal complexes or genetic lineages based on related multilocus STs (BURST). Seventeen clonal complexes were represented by 2 to 10 related allelic profiles (STs), while 33 lineages (including reference strains) consisted of single STs with 4 or fewer allelic identities to other STs found in the study. Expansion of the BURST analysis to a global analysis of all known pneumococcal STs (as of 27 November 2002) reduced the number of single ST lineages from 33 to 8, and the number of multi-ST clonal complexes was reduced from 17 to 13. In this work, we established the basic genetic structure within individual serotypes prior to PC7V use. The resultant database will be useful for detecting potential selective effects of this vaccine in postvaccine surveillance.     

Impact of an Integrated Adolescent Reproductive Health Program in Brazil

An impact evaluation of an integrated school- and health-clinic-based adolescent reproductive health initiative was undertaken by the State Secretariats of Health and Education in Bahia, Brazil during 1997-99. The project was initiated in response to continued high pregnancy rates among adolescents and growing numbers of new HIV infections among young adults. It sought to promote responsible sexual and health-seeking behaviors among public secondary-school students, including the use of public health clinics. The study design included a matched control group used to measure project impact. The findings indicate that the project was successful in increasing the flow of sexual and reproductive health information to secondary-school students and that it had an impact on adolescents' intentions to use public health clinics in the future. No effects on sexual or contraceptive-use behaviors or on use of public clinics were observed, however. Client exit-interview data from a subset of project clinics indicate that adolescents who use clinic-based services are overwhelmingly female and considerably older on average and much more likely ever to have been pregnant than are adolescents in the target population for the project.