title: Nasopharyngeal carriage of Streptococcus pneumoniae among children in an urban setting in Brazil prior to PCV10 introduction.
abstract: Information on pneumococcal carriage in the pre-vaccine period is essential to predict and assess the impact of PCV in settings where disease surveillance is particularly difficult. Therefore, we present data on pneumococcal carriage before the introduction of the 10-valent-pneumococcal conjugate vaccine (PCV10) in Brazil. We conducted a prospective study on a cohort of 203 children aged <5 years old, randomly selected in an urban community located in the periphery of the city of Salvador, Brazil and followed them from January/2008 to January/2009. Nasopharyngeal swabs were collected from each child at four times. In total, 721 swabs were collected, yielding a pneumococcal carriage prevalence of 55% (n=398). In multivariate analyses, the variables associated with carriage were having contact with three or more children <2 years old (OR, 2.00; 95% CI 1.33-2.89) and living in a house with an average of 3 residents per room (OR, 1.77; 95% CI 1.05-3.10). Also, white participants were more likely to be protected from colonization (OR, 0.52; 95% CI 0.29-0.93), and prevalence of carriage varied over time, with lower prevalence occurring from February to June (OR, 0.53; 95% CI 0.37-0.78) compared to July to January. Contact with children under 2 years of age and living in crowded housing also were associated with colonization by highly invasive serotypes, although this relationship was not significant. The most prevalent vaccine serotypes were 6A/B (25.4%), 19F (10.1%) and 14 (9.0%), while the most prevalent non-vaccine serotypes were 16F (4.8%), 15B/C (4.5%) and 6C/D (3.5%). Overall, 38.4% (153/398) of the isolates were non-susceptible to penicillin, and of those, 73.8% (113/153) were non-susceptible to trimethoprim/sulfamethoxazole. Colonization rate by PCV10 serotypes was 52.2%. Routine PCV10 vaccination can lead to significant changes in pneumococcal serotypes found in NP colonization, indicating a need for continued monitoring, especially in crowded settings, as occurs in Brazil's slums.
authors.affiliation: Centro de Pesquisas Gonçalo Moniz, Fundação Oswaldo Cruz, Salvador, Brazil.
authors.forename: Ana Paula de O
authors.initials: AP
authors.lastname: Menezes
authors.affiliation: Centro de Pesquisas Gonçalo Moniz, Fundação Oswaldo Cruz, Salvador, Brazil.
authors.forename: Jailton
authors.initials: J
authors.lastname: Azevedo
authors.affiliation: Faculdade de Farmácia, Universidade Federal da Bahia, Salvador, Brazil.
authors.forename: Mariela C
authors.initials: MC
authors.lastname: Leite
authors.affiliation: Centro de Pesquisas Gonçalo Moniz, Fundação Oswaldo Cruz, Salvador, Brazil.
authors.forename: Leila C
authors.initials: LC
authors.lastname: Campos
authors.affiliation: Escola Nacional de Saúde Pública, Fundação Oswaldo Cruz, Rio de Janeiro, RJ, Brazil.
authors.forename: Marcelo
authors.initials: M
authors.lastname: Cunha
authors.affiliation: Respiratory Diseases Branch, Centers for Disease Control & Prevention, Atlanta, GA, USA.
authors.forename: Maria da Gloria S
authors.initials: Mda G
authors.lastname: Carvalho
authors.affiliation: Centro de Pesquisas Gonçalo Moniz, Fundação Oswaldo Cruz, Salvador, Brazil.
authors.forename: Mitermayer G
authors.initials: MG
authors.lastname: Reis
authors.affiliation: Centro de Pesquisas Gonçalo Moniz, Fundação Oswaldo Cruz, Salvador, Brazil; Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, USA.
authors.forename: Albert I
authors.initials: AI
authors.lastname: Ko
authors.affiliation: Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, USA.
authors.forename: Daniel M
authors.initials: DM
authors.lastname: Weinberger
authors.affiliation: Centro de Pesquisas Gonçalo Moniz, Fundação Oswaldo Cruz, Salvador, Brazil; Instituto de Saúde Coletiva, Universidade Federal da Bahia, Salvador, Brazil.
authors.forename: Guilherme
authors.initials: G
authors.lastname: Ribeiro
authors.affiliation: Centro de Pesquisas Gonçalo Moniz, Fundação Oswaldo Cruz, Salvador, Brazil; Faculdade de Farmácia, Universidade Federal da Bahia, Salvador, Brazil. Electronic address: joice@ufba.br.
authors.forename: Joice N
authors.initials: JN
authors.lastname: Reis
mesh_terms: D001938:Brazil; D002353:Carrier State / Q000453:epidemiology* / Q000382:microbiology; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008826:Microbial Sensitivity Tests; D009305:Nasopharynx / Q000382:microbiology; D022242:Pneumococcal Vaccines; D015995:Prevalence; D011446:Prospective Studies; D012307:Risk Factors; D018571:Sentinel Surveillance; D065288:Serogroup; D013296:Streptococcus pneumoniae / Q000145:classification / Q000302:isolation & purification*; D014505:Urban Population; D014611:Vaccination / Q000706:statistics & numerical data
chemical_list: C586648:10-valent pneumococcal conjugate vaccine; D022242:Pneumococcal Vaccines
keywords: Children; Nasopharyngeal carriage; PCV10-vaccine; Serotypes; Streptococcus pneumoniae