Pneumococcal carriage in children attending a hospital outpatient clinic in the era of pneumococcal conjugate vaccines in Barcelona

Between April 2004 and March 2006 an oropharyngeal swab was obtained from 502 asymptomatic children, aged 6 months to 6 years, at a tertiary children's hospital outpatient department to assess the pneumococcal colonisation rate, risk factors, serotype distribution and antimicrobial susceptibility. Only 126 (25.3%) children had received >= 1 dose of PCV7. The pneumococcal carriage rate was 23.5%. Carrier rates were significantly higher in children aged >= 24 months and children attending daycare center. Thirty six (31.0%) of the isolates were contained in PCV7, 39 (33.6%) in PCV10 and 62 (53.4%) in PCV13. Forty-four strains (37.9%) were resistant to penicillin. Vaccine serotype (VT) strains were more likely to be penicillin-nonsusceptible S. pneumoniae than non-PCV7 serotype (NVT) strains (66.7% vs. 21.6%; P < 0.001). In our pediatric population, NVT were predominant among pneumococcal carriers whereas antibiotic resistance was significantly associated with VT. PCV13 can substantially increase the serotype coverage of S.pneumoniae in healthy carriers. (c) 2012 Elsevier Inc. All rights reserved.