1. Serotype distribution and antimicrobial susceptibilities of nasopharyngeal isolates of Streptococcus pneumoniae from healthy children in the 13-valent pneumococcal conjugate vaccine era
- Author
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Metta Maria Gabriella, Giorgio Bedogni, Dario Dilillo, Gandini Vera, Ballerini Emanuela, Travaini Marta, Brioschi Manuela, Bonvissuto Milena, Di Nello Francesca, Mazzucchi Elisabetta, Sala Natascia, Moscatiello Anna, Rubini Riccardo, Porta Norberto, Erminio Torresani, Dozzi Massimiliano, Benincaso Annarita, Decarlis Silvia, Vessia Chiara, Tomasetto Mariangela, Maria Gramegna, Maria Laura Garlaschi, Nannini Pilar, Marino Faccini, Chiara Mameli, Petruzzi Mariangela, Calloni Cinzia Simona, Bricalli Dorella, Picciotti Michela, Galli Erica, Gian Vincenzo Zuccotti, Pisanelli Stefania, Torcoletti Matteo, Laviola Franca, Valentini Maurizio, De Angelis Laura, Saitta Vincenzo, Laura Daprai, Scelza Giuseppina, Camiletti Marina Irene, Ramponi Giulia, Macedoni Maddalena, Giuliani Maria Grazia, Redaelli Francesca, Loda Barbara, Tiso Rosa Maria, Colella Giacomo, and Picicco Damiano
- Subjects
Serotype ,Male ,medicine.medical_specialty ,Microbial Sensitivity Tests ,medicine.disease_cause ,Pneumococcal conjugate vaccine ,Pneumococcal Infections ,Pneumococcal Vaccines ,Antibiotic resistance ,Internal medicine ,Nasopharynx ,Epidemiology ,Streptococcus pneumoniae ,Drug Resistance, Bacterial ,medicine ,Humans ,General Veterinary ,General Immunology and Microbiology ,Respiratory tract infections ,business.industry ,Public Health, Environmental and Occupational Health ,Infant ,Infectious Diseases ,Carriage ,Cross-Sectional Studies ,Pneumococcal vaccine ,Italy ,Child, Preschool ,Immunology ,Carrier State ,Molecular Medicine ,Female ,business ,medicine.drug - Abstract
Few epidemiological data are available since the introduction of 13-valent pneumococcal vaccine (PCV13) in 2010. We conducted a cross-sectional study to estimate the prevalence of Streptococcus pneumoniae (SP) nasopharyngeal carriage in healthy Italian infants and young children and to evaluate the impact of PCV13 on pneumococcal colonization. In the trimester September-December 2011 nasopharyngeal swabs were collected from healthy children aged 3-59 months presenting for routine well careat 16 primary care pediatricians in Milan. SP carriage isolates were serotyped and tested for antimicrobial resistance using EUCAST breakpoints. Among 1250 enrolled children, 618 had received at least 1 dose of PCV13, 292 at least 1 dose of PCV7, 94 a combination of the two vaccines and 246 were not vaccinated. The prevalence of SP carriage was 27% (95% confidence interval [CI] 25-30). At multivariable analysis, age≥25 months (prevalence ratio [PR]=0.74) and use of antibiotics in the previous 3 months (PR=0.67) were associated with lower SP carriage prevalence. Having siblings (PR=1.79 for 1 sibling and PR=2.23 for ≥2 siblings), day-care attendance (PR=2.27) and respiratory tract infections in the previous 3 months (PR=1.39) were associated with higher SP carriage prevalence. The immunization status for SP was not associated with SP carriage at univariable or at multivariable analysis. The most common carriage isolates were 6C, 19A and 23A. The prevalence of the six additional PCV13 serotypes carriage in children appropriately vaccinated with PCV13 was lower than in children appropriately vaccinated with PCV7 (0 vs. 0.060); the greater reduction in prevalence of carriage was observed for serotype 19A (0 vs. 0.041). Serotype 6C was the most common drug-resistant serotype (17.2%). Further epidemiological studies are needed to assess changes in circulating SP serotypes following the large-scale introduction of PCV13.
- Published
- 2013