title: Non-invasive pneumococcal serotypes and antimicrobial susceptibilities in a paediatric hospital in the era of conjugate vaccines.
abstract: To evaluate the effects of 7-valent pneumococcal conjugate vaccine (PCV7) introduction to the routine childhood immunisation schedule in 2008 and its replacement by PCV13 in 2010 in Ireland, we surveyed the serotypes and antimicrobial susceptibilities of 339 pneumococci associated with carriage and non-invasive infection (NII) in a Dublin paediatric hospital from 2009 to 2012. Furthermore, we compared the distribution of pneumococcal serotypes collected from 2009 to 2012 to 105 NII pneumococci isolated in 2007, the year before conjugate vaccine introduction. PCV7 serotypes declined from 2007 to 2012 as follows: carriage, 67-23% (p=0.0004); conjunctivitis, 58-0% (p<0.0001); non-bacteraemic lower respiratory tract infection, 50-19% (p=0.0363) and otitis media 54-27%. Notably, antimicrobial resistant (AMR) PCV7 serotypes showed a significant decrease by the end of the study period (i.e. 2012) (p<0.0001). Compared with 2007 the overall occurrence of serotype 19A increased from 1.9 to 10% in 2010 (p=0.0132) and to 15% in 2011 (p=0.0005). Importantly, serotype 19A declined significantly from 2011 levels to an overall prevalence of 4.8% in 2012 (p=0.0243). Most striking was the significant reduction of AMR 19A (p=0.0195). Conversely, increases were observed in non-vaccine type (NVT) pneumococci in 2009-2012, of which serotypes 11A (n=30), 15B/C (n=17), 22F (n=14), 35Bn=13), non-typeable pneumococci (n=13) and 23A (n=12) were the most prevalent. Moreover, an increase in NVT non-susceptible to at least one antimicrobial in 2009-2012 was noted, attributable to serotypes 35B (n=10) and 15A (n=7). In summary, this study has shown that PCV7 and PCV13 introduction has had a positive impact on their target serotypes and antimicrobial resistance amongst pneumococci within a paediatric hospital within a short time period. However, the increase in NVT prevalence highlights the need for continued surveillance.
authors.affiliation: Epidemiology and Molecular Biology Unit and Irish Meningococcal and Meningitis Reference Laboratory, Temple Street Children's University Hospital, Dublin, Ireland; Department of Clinical Microbiology, RCSI Education and Research Centre, Beaumont Hospital, Dublin, Ireland. Electronic address: martha.mcelligott@cuh.ie.
authors.forename: Martha
authors.initials: M
authors.lastname: McElligott
authors.affiliation: Epidemiology and Molecular Biology Unit and Irish Meningococcal and Meningitis Reference Laboratory, Temple Street Children's University Hospital, Dublin, Ireland; Department of Clinical Microbiology, RCSI Education and Research Centre, Beaumont Hospital, Dublin, Ireland.
authors.forename: Imelda
authors.initials: I
authors.lastname: Vickers
authors.affiliation: Epidemiology and Molecular Biology Unit and Irish Meningococcal and Meningitis Reference Laboratory, Temple Street Children's University Hospital, Dublin, Ireland; Department of Clinical Microbiology, RCSI Education and Research Centre, Beaumont Hospital, Dublin, Ireland.
authors.forename: Mary
authors.initials: M
authors.lastname: Cafferkey
authors.affiliation: Epidemiology and Molecular Biology Unit and Irish Meningococcal and Meningitis Reference Laboratory, Temple Street Children's University Hospital, Dublin, Ireland; Health Protection Surveillance Centre, Dublin, Ireland.
authors.forename: Robert
authors.initials: R
authors.lastname: Cunney
authors.affiliation: Department of Clinical Microbiology, RCSI Education and Research Centre, Beaumont Hospital, Dublin, Ireland; Department of Microbiology, Beaumont Hospital, Dublin, Ireland.
authors.forename: Hilary
authors.initials: H
authors.lastname: Humphreys
mesh_terms: D002353:Carrier State / Q000382:microbiology; D002648:Child; D024881:Drug Resistance, Bacterial; D000069443:Heptavalent Pneumococcal Conjugate Vaccine; D006776:Hospitals, Pediatric; D006801:Humans; D007494:Ireland / Q000453:epidemiology; D011008:Pneumococcal Infections / Q000453:epidemiology* / Q000382:microbiology; D022242:Pneumococcal Vaccines / Q000627:therapeutic use; D018571:Sentinel Surveillance; D012703:Serotyping; D013296:Streptococcus pneumoniae / Q000145:classification* / Q000302:isolation & purification; D018074:Vaccines, Conjugate / Q000627:therapeutic use
chemical_list: C538862:13-valent pneumococcal vaccine; D000069443:Heptavalent Pneumococcal Conjugate Vaccine; D022242:Pneumococcal Vaccines; D018074:Vaccines, Conjugate
keywords: 7/13-valent pneumococcal conjugate vaccines; Antimicrobial resistance; Epidemiology; Non-vaccine type pneumococci; Serotypes; Streptococcus pneumoniae