Avaliação da ocorrência de rotavírus do grupo a após a implantação da vacina oral de rotavírus humano - VORH e análise comparativa das amostras circulantes antes e após a implantação da VORH em Goiânia – Goiás

• Main Author: Almeida , Tâmera Nunes Vieira
• Publication Date: 2011
• Format: Master thesis
• Language: por
• Source: Repositório Institucional da UFG
• dARK ID: ark:/38995/001300000bk14
• Download full: http://repositorio.bc.ufg.br/tede/handle/tede/6780
• topic: Rotavírus do grupo A; Gastroenterite infantil; Vacina; Group A rotavirus; Child gastroenteritis; Vaccine; CIENCIAS BIOLOGICAS::MICROBIOLOGIA

The group A rotaviruses (RVA) are recognized as the main viral agents of acute childhood gastroenteritis, and due to the high morbidity-mortality rates vaccination has being considered the best alternative for prevention and control of RVA. In Brazil, in March, 2006 the Ministry of Health included the human rotavirus oral vaccine – VORH, which was developed from a monovalent attenuated strain G1P[8], in the National Immunization Program. In this context, the present study aimed at the investigation of the occurrence of RVA infections in the city of Goiânia after the implementation of the VORH, as well as the comparative analysis of the RVA circulating strains during the pre- and post-vaccination periods. For the RVA identification, 65 fecal samples obtained from children with acute gastroenteritis, in the period from 2008 to 2009, were tested by an immunoenzymatic assay and by polyacrilamide gel electrophoresis, with a total detection rate of 16.9% (11/65). After molecular characterization, the G2 genotype was identified in 10 samples, and four of those were considered as G2P[4] genotype. For the comparative analysis, the G2P[4] samples, as well as other 15 samples, obtained in the pre- and post-vaccination periods, were submitted to genomic sequencing of the coding regions for the proteins VP6, VP7 and NSP4. The molecular characterization of the VP7 gene showed that the G1 samples belonged to lineages I and II, sublineages d and b, respectively, and that all the G2 samples belonged to lineage II, with the differentiation of three sublineages, a, c and d, which were correlated with the collection periods. Regarding the VP6 genogroups and the NSP4 genotypes, a predominance of genogroup I and genotype A in postvaccination period was observed, whereas a predominance of genogroup II and genotype B was identified in the period before de vaccine implementation. The association between the G and P genotypes with VP6 genogroups and NSP4 genotypes revealed the predominance of the G1-P[8]-II-B combination in the pre-vaccination period, and the association G2-P[4]-I-A in the post-vaccination period, which suggests the substitution of these combinations after the implementation of the VORH.