Caracterização molecular de rotavírus como causador de diarreia em população de duas regiões geográficas do Brasil
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Data
2013
Autores
Leite, Marcel [UNIFESP]
Orientadores
Granato, Celso Francisco Hernandes [UNIFESP]
Tipo
Dissertação de mestrado
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Em escala global, o rotavirus e considerado como o principal causador da diarreia infantil grave, acometendo, principalmente, criancas entre 0 e 5 anos. Em marco de 2006, a vacina Rotarix® (oral, cepa G1P[8] atenuada de origem humana) foi incluida no calendario vacinal brasileiro. Dados do ministerio da Saúde revelam que no ano de 2009 a cobertura nacional deste imunizante foi de 84,4%. Relatos sobre o aumento na circulacao da cepa G2P[4], apos 2006, trouxeram a tona a discussao ao redor da eficacia deste imunizante, para as cepas nao G1. Considerando que a epidemiologia molecular do rotavirus pode apresentar dados para o aprimoramento do controle vacinal na populacao infantil, o objetivo deste estudo foi identificar os genotipos de rotavirus circulantes, em 2 regioes brasileiras, durante o ano de 2009. Um total de 223 amostras de fezes, provenientes das regioes Nordeste (Bahia e Pernambuco) e Sudeste (São Paulo e Rio de Janeiro), com resultado previamente positivo para rotavirus (Imunocromatografia) foram submetidas a tecnica nested RT-PCR para serem genotipadas de acordo com as proteinas VP7 (G) e VP4 (P). A caracterizacao genotipica do rotavirus foi obtida em 175 amostras (78,5%). Para essas amostras, a idade dos pacientes variou entre 0 a 83 anos (media de 15,6 anos e mediana de 6 anos), sendo 46,3% na faixa de 0 a 5 anos, 50,9% eram individuos do sexo feminino e, com relacao a regiao de origem, 52,6% foram provenientes da regiao Nordeste e 47,4% da regiao Sudeste. Em relacao a sazonalidade, 59,0% (Sudeste) e 73,9% (Nordeste) das amostras genotipadas foram colhidas entre os meses de junho e setembro. Para a genotipagem de VP7, foi observada circulacao dos genotipos G1, G2 e G4 (Nordeste) e G2, G3, G5 e G9 (Sudeste), enquanto que para VP4 foi observada circulacao de P[4], P[8], P[6] e P[9] (Nordeste e Sudeste). As associacoes de G e P mais frequentes no Nordeste foram G2P[4]/G2P[NT] (81,4%), G2P[6] (5,2%) e G1P[6] (5,2%), enquanto que no Sudeste foram G2P[4]/G2P[NT] (78,8%), G2P[6] (8,2%) e G9P[8] (4,7%). Entre os individuos de 0 a 4 anos que foram imunizados contra o rotavirus (15,1%), o genotipo G2P[4]/G2P[NT] foi identificado em 91,0% e naqueles com mesma faixa etaria que nao foram imunizados (9,6%) o genotipo G2P[4]/G2P[NT] foi encontrado em 85,7%. Tais achados, em concordancia com o alto indice de cobertura vacinal, sugerem que a circulacao de G2P[4] nas regioes estudadas apresentou aumento consideravel apos a adocao da Rotarix® no calendario vacinal
Rotavirus is the main cause of severe childhood diarrhea globally among children under 5 years of age. In March 2006, the live attenuated human rotavirus vaccine Rotarix® (G1P[8] strain) was introduced into Brazil's National Immunization Programme. According to Ministry of Health data, the vaccine coverage rate was 84.4% in 2009. Evidences of increasing G2P[4] genotype circulation after 2006 opened up the discussion about the vaccine effectiveness to non-G1 strains. Considering that data of molecular epidemiology of rotaviruses can contribute to a better vaccine control in infants, the aim of this study was to identify the circulating rotavirus genotypes in two distinct Brazilian regions during 2009. A total of 223 fecal samples previously positive to rotavirus by immunochromatography and latex agglutination assay, from Northeastern (Bahia and Pernambuco) and Southeastern (Sao Paulo and Rio de Janeiro) regions were included in the study. All the samples were submitted to genotyping by nested-PCR according to VP7 (G) e VP4 (P) proteins and 175 samples (78.5%) could be characterized. The population ranged in age from 0 to 83 years (average 15.6 years and median 6 years), and 46.3% ranged from 0 to 5 years. Fifty one percent were females. The distribution according to geographic origin was 52.6% for Northeastern, and 47,4% for Southeastern. According to seasonality, 59.0% and 73.9% of genotyped samples were collected between June and September for Southeastern and Northeastern respectively. Analyzing the VP7 genotyping, the G types detected were G1, G2 and G4 (Northeast), and G2, G3, G5 and G9 (Southeast). Analyzing the VP4 genotyping, the P types detected were P[4], P[8], P[6] and P[9] (Northeast and Southeast). Additionally, the most frequent mixed types found were G2P[4]/G2P[NT] (81.4%), G2P[6] (5.2%) and G1P[6] (5.2%) in Northeast, and G2P[4]/G2P[NT] (78.8%), G2P[6] (8.2%) e G9P[8] (4.7%) in Southeast. Among immunized individuals ranged from 0 to 4 years (15.1%), the G2P[4]/G2P[NT] genotype was identified in 91,0% of cases, and among non-immunized individuals at the same age (9.6%), the G2P[4]/G2P[NT] genotype was identified in 85.7% of cases. In accordance with the high level of vaccine coverage, these data suggest that the circulation of G2P[4] genotype in Southeast and Northeast regions had a considerable increase after the introduction of Rotarix® into the National Immunization Programme.
Rotavirus is the main cause of severe childhood diarrhea globally among children under 5 years of age. In March 2006, the live attenuated human rotavirus vaccine Rotarix® (G1P[8] strain) was introduced into Brazil's National Immunization Programme. According to Ministry of Health data, the vaccine coverage rate was 84.4% in 2009. Evidences of increasing G2P[4] genotype circulation after 2006 opened up the discussion about the vaccine effectiveness to non-G1 strains. Considering that data of molecular epidemiology of rotaviruses can contribute to a better vaccine control in infants, the aim of this study was to identify the circulating rotavirus genotypes in two distinct Brazilian regions during 2009. A total of 223 fecal samples previously positive to rotavirus by immunochromatography and latex agglutination assay, from Northeastern (Bahia and Pernambuco) and Southeastern (Sao Paulo and Rio de Janeiro) regions were included in the study. All the samples were submitted to genotyping by nested-PCR according to VP7 (G) e VP4 (P) proteins and 175 samples (78.5%) could be characterized. The population ranged in age from 0 to 83 years (average 15.6 years and median 6 years), and 46.3% ranged from 0 to 5 years. Fifty one percent were females. The distribution according to geographic origin was 52.6% for Northeastern, and 47,4% for Southeastern. According to seasonality, 59.0% and 73.9% of genotyped samples were collected between June and September for Southeastern and Northeastern respectively. Analyzing the VP7 genotyping, the G types detected were G1, G2 and G4 (Northeast), and G2, G3, G5 and G9 (Southeast). Analyzing the VP4 genotyping, the P types detected were P[4], P[8], P[6] and P[9] (Northeast and Southeast). Additionally, the most frequent mixed types found were G2P[4]/G2P[NT] (81.4%), G2P[6] (5.2%) and G1P[6] (5.2%) in Northeast, and G2P[4]/G2P[NT] (78.8%), G2P[6] (8.2%) e G9P[8] (4.7%) in Southeast. Among immunized individuals ranged from 0 to 4 years (15.1%), the G2P[4]/G2P[NT] genotype was identified in 91,0% of cases, and among non-immunized individuals at the same age (9.6%), the G2P[4]/G2P[NT] genotype was identified in 85.7% of cases. In accordance with the high level of vaccine coverage, these data suggest that the circulation of G2P[4] genotype in Southeast and Northeast regions had a considerable increase after the introduction of Rotarix® into the National Immunization Programme.
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Citação
LEITE, Marcel. Caracterização molecular de rotavírus como causador de diarréia em população de duas regiões geográficas do Brasil. 2013. 108 f. Dissertação (Mestrado em Ciências) – Escola Paulista de Medicina, Universidade Federal de São Paulo. São Paulo, 2013.