Evaluation of Haemophilus influenzaetype b carrier status among children 10 years after the introduction of Hib vaccine in Brazil

• Autor(a) principal: Zanella,Rosemeire Cobo
• Data de Publicação: 2015
• Outros Autores: Brandileone,Maria Cristina de Cunto, Andrade,Ana Lúcia, Ogassavara,Cinthya Terumi, Fiório,Cleiton Eduardo, Brandão,Angela Pires, Almeida,Samanta Cristine Grassi, Lemos,Ana Paula Silva, Gorla,Maria Cecília, Carvalhanas,Telma Regina, Sato,Helena, Liphaus,Bernadete, Nerger,Maria Lígia, Conde,Monica, Ribeiro,Ana Freitas
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Memórias do Instituto Oswaldo Cruz
• Texto Completo: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0074-02762015000600755
• topic: Haemophilus influenzae; type b; nasopharyngeal carriage; Hib conjugate vaccine; Brazil

The aim of the present study was to assess the prevalence of Haemophilus influenzaetype b (Hib) nasopharyngeal (NP) colonisation among healthy children where Hib vaccination using a 3p+0 dosing schedule has been routinely administered for 10 years with sustained coverage (> 90%). NP swabs were collected from 2,558 children who had received the Hib vaccine, of whom 1,379 were 12-< 24 months (m) old and 1,179 were 48-< 60 m old. Hi strains were identified by molecular methods. Hi carriage prevalence was 45.1% (1,153/2,558) and the prevalence in the 12-< 24 m and 48-< 60 m age groups were 37.5% (517/1,379) and 53.9% (636/1,179), respectively. Hib was identified in 0.6% (16/2,558) of all children in the study, being 0.8% (11/1,379) and 0.4% (5/1,179) among the 12-< 24 m and 48-< 60 m age groups, respectively. The nonencapsulate Hi colonisation was 43% (n = 1,099) and was significantly more frequent at 48-< 60 m of age (51.6%, n = 608) compared with that at 12-< 24 m of age (35.6%, n = 491). The overall resistance rates to ampicillin and chloramphenicol were 16.5% and 3.7%, respectively; the co-resistance was detected in 2.6%. Our findings showed that the Hib carrier rate in healthy children under five years was very low after 10 years of the introduction of the Hib vaccine.