Has the licensing of respiratory quinolones for adults and the 7-valent pneumococcal conjugate vaccine (PCV-7) for children had herd effects with respect to antimicrobial non-susceptibility in invasive Streptococcus pneumoniae?

OBJECTIVES: The aim of the study was to analyse the evolution of antibiotic non-susceptibility in Spanish invasive Streptococcus pneumoniae after licensure of respiratory-quinolones for adults and 7-valent pneumococcal conjugate vaccine (PCV-7) for immunization of children.

METHODS: All invasive pneumococci received in the Reference Laboratory (January 2000-August 2007; n = 12 957 isolates) were serotyped, and susceptibility to penicillin/erythromycin/levofloxacin was determined. Antibiotic consumption and PCV-7 doses/year were provided by IMS and the manufacturer, respectively.

RESULTS: In 2000-07, PCV-7 distribution (doses/1000 inhabitants
CONCLUSIONS: This ecological analysis suggests that PCV-7 vaccination in children had a herd effect in adults, but consumption of respiratory quinolones in adults had no effect on pneumococcal susceptibility to levofloxacin in children. Penicillin/erythromycin non-susceptibility decreased along the studied period among paediatric invasive S. pneumoniae isolates to a level similar to that seen in adults.