Serotype distribution and antimicrobial susceptibilities of nasopharyngeal isolates of Streptococcus pneumoniae from healthy children in the 13-valent pneumococcal conjugate vaccine era

Gianvincenzo Zuccotti, Chiara Mameli, Laura Daprai, Maria Laura Garlaschi, Dario Dilillo, Giorgio Bedogni, Marino Faccini, Maria Gramegna, Erminio Torresani, Emanuela Ballerini, Annarita Benincaso, Milena Bonvissuto, Dorella Bricalli, Manuela Brioschi, Cinzia Simona Calloni, Marina Irene Camiletti, Giacomo Colella, Laura De Angelis, Silvia Decarlis, Francesca Di Nello, Massimiliano Dozzi, Erica Galli, Vera Gandini, Maria Grazia Giuliani, Franca Laviola, Barbara Loda, Maddalena Macedoni, Elisabetta Mazzucchi, Maria Gabriella Metta, Anna Moscatiello, Pilar Nannini, Mariangela Petruzzi, Damiano Picicco, Michela Picciotti, Stefania Pisanelli, Norberto Porta, Giulia Ramponi, Francesca Redaelli, Riccardo Rubini, Natascia Sala, Vincenzo Saitta, Giuseppina Scelza, Rosa Maria Tiso, Mariangela Tomasetto, Matteo Torcoletti, Marta Travaini, Maurizio Valentini, Chiara Vessia
Vaccine 2014 January 23, 32 (5): 527-34
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.

Full Text Links

Find Full Text Links for this Article


You are not logged in. Sign Up or Log In to join the discussion.

Related Papers

Remove bar
Read by QxMD icon Read

Save your favorite articles in one place with a free QxMD account.


Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"