title: Pneumococcal nasopharyngeal carriage among children in Brazil prior to the introduction of the 10-valent conjugate vaccine: a culture- and PCR-based survey.
abstract: We performed two different approaches (broth enrichment step prior to culture (BEC) and PCR (BEPCR)) for detecting Streptococcus pneumoniae from nasopharyngeal specimens collected from 242 children aged <6 years attending one hospital (n = 140) and one childcare centre (n = 102) in a major urban area in Brazil. These specimens were collected immediately before the introduction of the 10-valent pneumococcal conjugate vaccine (PCV10) and the 13-valent vaccine (PCV13) for routine use in Brazil. Results were compared with previous findings obtained with direct culture (DC) on a selective medium. Colonisation prevalence was 58·3% (n = 141), being higher among children attending the childcare centre (62·7% vs. 55%). The culture-based methods (DC and BEC) enabled the detection of S. pneumoniae in 119 (49·2%) and 115 (47·5%) children, respectively. The PCR-based method (BEPCR) was more sensitive and 137 (56·6%) carriers were identified. Twenty-six serogroups/serotypes were identified, predominantly 6B, 19F, 14, 6A, 15C and 23F. Multiple colonisation was observed in 13 (5·4%) children. The estimated serotypes coverage of available PCVs was 40·4% for the 10-valent (included in the Brazilian immunisation programme) and 55·8% for the 13-valent (only available in private clinics). The use of robust approaches to obtain a more realistic insight about the asymptomatic carrier status is of paramount importance to estimate and assess the impact of vaccine implementation. The combination between culture-based and molecular methods constitutes a suitable strategy.
authors.affiliation: Department of Microbiology and Parasitology,Universidade Federal Fluminense,Niterói, Rio de Janeiro,Brazil.
authors.forename: H G
authors.initials: HG
authors.lastname: Rodrigues
authors.affiliation: Department of Medical Microbiology,Universidade Federal do Rio de Janeiro,Rio de Janeiro,Brazil.
authors.forename: T C A
authors.initials: TCA
authors.lastname: Pinto
authors.affiliation: Department of Microbiology and Parasitology,Universidade Federal Fluminense,Niterói, Rio de Janeiro,Brazil.
authors.forename: R R
authors.initials: RR
authors.lastname: Barros
authors.affiliation: Department of Medical Microbiology,Universidade Federal do Rio de Janeiro,Rio de Janeiro,Brazil.
authors.forename: L M
authors.initials: LM
authors.lastname: Teixeira
authors.affiliation: Department of Microbiology and Parasitology,Universidade Federal Fluminense,Niterói, Rio de Janeiro,Brazil.
authors.forename: F P G
authors.identifier: 0000-0002-3606-2540
authors.initials: FPG
authors.lastname: Neves
mesh_terms: D001938:Brazil / Q000453:epidemiology; D002353:Carrier State / Q000453:epidemiology / Q000382:microbiology; D002675:Child, Preschool; D015169:Colony Count, Microbial; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D009305:Nasopharynx / Q000382:microbiology*; D011008:Pneumococcal Infections / Q000453:epidemiology* / Q000382:microbiology*; D022242:Pneumococcal Vaccines / Q000008:administration & dosage; D016133:Polymerase Chain Reaction; D013296:Streptococcus pneumoniae / Q000502:physiology*
chemical_list: C586648:10-valent pneumococcal conjugate vaccine; C538862:13-valent pneumococcal vaccine; D022242:Pneumococcal Vaccines
keywords: 
                 Streptococcus pneumoniae
              ; Colonisation; culture; pneumococcal conjugate vaccines; sequential multiplex PCR