Management of antibiotic-resistant Streptococcus pneumoniae infections and the use of pneumococcal conjugate vaccines.
The epidemiology of Streptococcus pneumoniae, a major cause of meningitis, pneumonia, bacteraemia and acute otitis media in both children and adults, has been altered by the availability of the seven-valent pneumococcal conjugate vaccine (PCV7) and selection pressure from broad-spectrum antibiotics. In Spain, the rates of antimicrobial consumption and resistance are high; of all S. pneumoniae isolates collected between 2001 and 2003, 9.2% were penicillin-resistant and 26.4% were penicillin-intermediate. These rates were even higher in children aged < or =4 years; 52.3% of isolates were penicillin-resistant or penicillin-intermediate. Serogroup 14 comprises nearly 9% of pneumococcal strains and exhibits the highest resistance to penicillin (69%). Since the introduction of PCV7 in Madrid, the isolates collected from hospitalized children aged <15 years from 21 hospitals revealed that only 8% of cases involving S. pneumoniae isolates were due to PCV7 serotypes, and no PCV7 vaccination failures were identified. These isolates demonstrated low rates of penicillin-non-susceptible and erythromycin-non-susceptible strains. Among multiresistant strains, serotype 19A was identified as most important. Although the recent WHO position paper on childhood immunizations speaks to the growing resistance of pneumococci, antibiotic resistance in Spain is noted to be decreasing and must be evaluated in conjunction with global studies.