RESUMO
Group A human rotaviruses (HuRVA) are causative agents of acute gastroenteritis. Six viral structural proteins (VPs) and six nonstructural proteins (NSPs) are produced in RV-infected cells. NSP4 is a diarrhoea-inducing viral enterotoxin and NSP4 gene analysis revealed at least 15 (E1-E15) genotypes. This study analysed the NSP4 genetic diversity of HuRVA G2P[4] strains collected in the state of São Paulo (SP) from 1994 and 2006-2010 using reverse transcription-polymerase chain reaction, sequencing and phylogenetic analysis. Forty (97.6%) G2P[4] strains displayed genotype E2; one strain (2.4%) displayed genotype E1. These results are consistent with the proposed linkage between VP4/VP7 (G2P[4]) and the NSP4 (E2) genotype of HuRVA. NSP4 phylogenetic analysis showed distinct clusters, with grouping of most strains by their genotype and collection year, and most strains from SP were clustered together with strains from other Brazilian states. A deduced amino acid sequence alignment for E2 showed many variations in the C-terminal region, including the VP4-binding domain. Considering the ability of NSP4 to generate host immunity, monitoring NSP4 variations, along with those in the VP4 or VP7 protein, is important for evaluating the circulation and pathogenesis of RV. Finally, the presence of one G2P[4]E1 strain reinforces the idea that new genotype combinations emerge through reassortment and independent segregation.
Assuntos
Antígenos Virais/isolamento & purificação , Glicoproteínas/genética , RNA Viral/genética , Rotavirus/genética , Toxinas Biológicas/genética , Proteínas não Estruturais Virais/genética , Adulto , Sequência de Aminoácidos , Sequência de Bases , Brasil , Criança , Fezes/virologia , Ligação Genética/genética , Variação Genética , Genótipo , Humanos , Técnicas Imunoenzimáticas , Dados de Sequência Molecular , Filogenia , RNA Viral/isolamento & purificação , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Rotavirus/classificação , Rotavirus/imunologia , Alinhamento de SequênciaRESUMO
Group A human rotaviruses (HuRVA) are causative agents of acute gastroenteritis. Six viral structural proteins (VPs) and six nonstructural proteins (NSPs) are produced in RV-infected cells. NSP4 is a diarrhoea-inducing viral enterotoxin and NSP4 gene analysis revealed at least 15 (E1-E15) genotypes. This study analysed the NSP4 genetic diversity of HuRVA G2P[4] strains collected in the state of São Paulo (SP) from 1994 and 2006-2010 using reverse transcription-polymerase chain reaction, sequencing and phylogenetic analysis. Forty (97.6%) G2P[4] strains displayed genotype E2; one strain (2.4%) displayed genotype E1. These results are consistent with the proposed linkage between VP4/VP7 (G2P[4]) and the NSP4 (E2) genotype of HuRVA. NSP4 phylogenetic analysis showed distinct clusters, with grouping of most strains by their genotype and collection year, and most strains from SP were clustered together with strains from other Brazilian states. A deduced amino acid sequence alignment for E2 showed many variations in the C-terminal region, including the VP4-binding domain. Considering the ability of NSP4 to generate host immunity, monitoring NSP4 variations, along with those in the VP4 or VP7 protein, is important for evaluating the circulation and pathogenesis of RV. Finally, the presence of one G2P[4]E1 strain reinforces the idea that new genotype combinations emerge through reassortment and independent segregation.
Assuntos
Adulto , Criança , Humanos , Antígenos Virais/isolamento & purificação , Glicoproteínas/genética , RNA Viral/genética , Rotavirus/genética , Toxinas Biológicas/genética , Proteínas não Estruturais Virais/genética , Sequência de Aminoácidos , Sequência de Bases , Brasil , Fezes/virologia , Variação Genética , Genótipo , Ligação Genética/genética , Técnicas Imunoenzimáticas , Dados de Sequência Molecular , Filogenia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , RNA Viral/isolamento & purificação , Rotavirus/classificação , Rotavirus/imunologia , Alinhamento de SequênciaRESUMO
RotaTeq® (Merck & Company, Inc, Whitehouse Station, NJ, USA) is an oral pentavalent rotavirus vaccine (RV5) that has shown high and consistent efficacy in preventing rotavirus gastroenteritis (RGE) in randomised clinical trials previously conducted in industrialised countries with high medical care resources. To date, the efficacy and effectiveness data for RV5 are available in some Latin American countries, but not Brazil. In this analysis, we projected the effectiveness of RV5 in terms of the percentage reduction in RGE-related hospitalisations among children less than five years of age in four regions of Brazil, using a previously validated mathematical model. The model inputs included hospital-based rotavirus surveillance data from Goiânia, Porto Alegre, Salvador and São Paulo from 2005-2006, which provided the proportions of rotavirus attributable to serotypes G1, G2, G3, G4 and G9, and published rotavirus serotype-specific efficacy from the Rotavirus Efficacy and Safety Trial. The model projected an overall percentage reduction of 93% in RGE-related hospitalisations, with an estimated annual reduction in RGE-related hospitalisations between 42,991-77,383 in the four combined regions of Brazil. These results suggest that RV5 could substantially prevent RGE-related hospitalisations in Brazil.
Assuntos
Gastroenterite/prevenção & controle , Infecções por Rotavirus/prevenção & controle , Vacinas contra Rotavirus/uso terapêutico , Adolescente , Brasil , Criança , Pré-Escolar , Feminino , Gastroenterite/virologia , Hospitalização , Humanos , Lactente , Masculino , Modelos Estatísticos , Avaliação de Programas e Projetos de Saúde , Vacinas Atenuadas/uso terapêuticoRESUMO
RotaTeq® (Merck & Company, Inc, Whitehouse Station, NJ, USA) is an oral pentavalent rotavirus vaccine (RV5) that has shown high and consistent efficacy in preventing rotavirus gastroenteritis (RGE) in randomised clinical trials previously conducted in industrialised countries with high medical care resources. To date, the efficacy and effectiveness data for RV5 are available in some Latin American countries, but not Brazil. In this analysis, we projected the effectiveness of RV5 in terms of the percentage reduction in RGE-related hospitalisations among children less than five years of age in four regions of Brazil, using a previously validated mathematical model. The model inputs included hospital-based rotavirus surveillance data from Goiânia, Porto Alegre, Salvador and São Paulo from 2005-2006, which provided the proportions of rotavirus attributable to serotypes G1, G2, G3, G4 and G9, and published rotavirus serotype-specific efficacy from the Rotavirus Efficacy and Safety Trial. The model projected an overall percentage reduction of 93 percent in RGE-related hospitalisations, with an estimated annual reduction in RGE-related hospitalisations between 42,991-77,383 in the four combined regions of Brazil. These results suggest that RV5 could substantially prevent RGE-related hospitalisations in Brazil.
Assuntos
Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Gastroenterite , Infecções por Rotavirus , Vacinas contra Rotavirus , Brasil , Gastroenterite , Hospitalização , Modelos Estatísticos , Avaliação de Programas e Projetos de Saúde , Vacinas AtenuadasRESUMO
In this study, 331 samples from calves less than one month old from a dairy herd in the district of Piracanjuba, state of Goiás, Brazil were tested for rotavirus. Thirty-three samples (9.9 percent) tested positive for rotavirus. Out of those, 31 were submitted to G and P characterization by reverse transcription followed by semi-nested polymerase chain reaction. Two samples were characterized as G6P[1], three as G10P[11] and five as G6P[11]. The majority of the samples (51.6 percent) displayed multiple P genotypes (P-genotype mixtures), including typical human genotypes P[4] and P[6M], suggesting the occurrence of co-infections and genetic reassortment. Also, the detection of human genotypes in bovine samples may be considered evidence of the zoonotic potential of rotaviruses. To our knowledge, this is the first report of such a high frequency of P genotype mixtures in bovine rotavirus samples. It also increases data on G and P rotavirus genotypes circulating in dairy herds in Brazil and can help in the development of more efficient immunization approaches, thereby controlling infection and reducing economical losses.
Assuntos
Animais , Bovinos , Humanos , Doenças dos Bovinos , Fezes , RNA Viral , Infecções por Rotavirus/veterinária , Rotavirus , Brasil , Doenças dos Bovinos , Eletroforese em Gel de Poliacrilamida , Genótipo , Reação em Cadeia da Polimerase , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Infecções por Rotavirus , Infecções por Rotavirus , Rotavirus , RotavirusRESUMO
BACKGROUND: Brazil implemented routine immunization with the human rotavirus vaccine, Rotarix, in 2006 and vaccination coverage reached 81% in 2008 in São Paulo. Our aim was to assess the impact of immunization on the incidence of severe rotavirus acute gastroenteritis (AGE). METHODS: We performed a 5-year (2004-2008) prospective surveillance at a sentinel hospital in São Paulo, with routine testing for rotavirus in all children less than 5 years of age hospitalized with AGE. Genotypes of positive samples were determined by reverse transcription polymerase chain reaction. RESULTS: During the study, 655 children hospitalized with AGE were enrolled; of whom 169 (25.8%) were positive for rotavirus. In the postvaccine period, a 59% reduction in the number of hospitalizations of rotavirus AGE and a 42.2% (95% confidence interval [CI], 18.6%-59.0%; P = 0.001) reduction in the proportion of rotavirus-positive results among children younger than 5 years were observed, with the greatest decline among infants (69.2%; 95% CI, 24.7%-87.4%; P = 0.004). Furthermore, the number of all-cause hospitalizations for AGE was reduced by 29% among children aged <5 years. The onset and peak incidences of rotavirus AGE occurred 3 months later in the 2007 and 2008 seasons compared with previous years. Genotype G2 accounted for 15%, 70%, and 100% of all cases identified, respectively, in 2006, 2007, and 2008. CONCLUSIONS: After vaccine implementation, a marked decline in rotavirus AGE hospitalizations was demonstrated among children younger than 5 years of age, with the greatest reduction in the age groups targeted for vaccination. The predominance of genotype G2P[4] highlights the need of continued postlicensure surveillance studies.
Assuntos
Gastroenterite/epidemiologia , Infecções por Rotavirus/epidemiologia , Vacinas contra Rotavirus/administração & dosagem , Doença Aguda , Brasil/epidemiologia , Distribuição de Qui-Quadrado , Pré-Escolar , Fezes/virologia , Gastroenterite/prevenção & controle , Gastroenterite/virologia , Hospitalização/estatística & dados numéricos , Humanos , Lactente , Recém-Nascido , Vigilância da População , Estudos Prospectivos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Rotavirus/genética , Rotavirus/imunologia , Rotavirus/isolamento & purificação , Infecções por Rotavirus/prevenção & controle , Infecções por Rotavirus/virologia , Vacinas contra Rotavirus/imunologia , Vacinas Atenuadas/administração & dosagem , Vacinas Atenuadas/imunologiaRESUMO
In this study, 331 samples from calves less than one month old from a dairy herd in the district of Piracanjuba, state of Goiás, Brazil were tested for rotavirus. Thirty-three samples (9.9%) tested positive for rotavirus. Out of those, 31 were submitted to G and P characterization by reverse transcription followed by semi-nested polymerase chain reaction. Two samples were characterized as G6P[1], three as G10P[11] and five as G6P[11]. The majority of the samples (51.6%) displayed multiple P genotypes (P-genotype mixtures), including typical human genotypes P[4] and P[6M], suggesting the occurrence of co-infections and genetic reassortment. Also, the detection of human genotypes in bovine samples may be considered evidence of the zoonotic potential of rotaviruses. To our knowledge, this is the first report of such a high frequency of P genotype mixtures in bovine rotavirus samples. It also increases data on G and P rotavirus genotypes circulating in dairy herds in Brazil and can help in the development of more efficient immunization approaches, thereby controlling infection and reducing economical losses.
Assuntos
Doenças dos Bovinos/virologia , Fezes/virologia , RNA Viral/genética , Infecções por Rotavirus/veterinária , Rotavirus/genética , Animais , Brasil/epidemiologia , Bovinos , Doenças dos Bovinos/epidemiologia , Eletroforese em Gel de Poliacrilamida , Genótipo , Humanos , Reação em Cadeia da Polimerase , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Rotavirus/classificação , Rotavirus/isolamento & purificação , Infecções por Rotavirus/epidemiologia , Infecções por Rotavirus/virologiaRESUMO
BACKGROUND: Rotavirus is a major cause of gastroenteritis in children. Knowledge of rotavirus genotypes is important for vaccination strategies. METHODS: During 2005-2006, rotavirus surveillance studies were conducted in São Paulo, Salvador, Goiânia, and Porto Alegre, Brazil. Stool samples were collected from children <5 years of age who had diarrhea and were screened by the Rotaclone Enzyme Immunoassay for the presence of rotavirus. Confirmed rotavirus-positive samples were characterized for P and G genotypes by reverse-transcriptase polymerase chain reaction. RESULTS: A total of 510 stool samples were collected. Of these, 221 (43.3%) were positive for rotavirus. Overall, G9 was the predominant G type, followed by G2, and G1; P[4] and P[8] were the predominant P types. The most frequent G/P genotype combination detected was G2P[4], followed by G9P[8], G9P[4], and G1P[8]. G2P[4] was the predominant type in Goiânia and Salvador; G9P[8] and G1P[8] were predominant in São Paulo and Porto Alegre, respectively. CONCLUSIONS: The prevalence, seasonality, and genotype distribution of rotavirus infection varied in different regions in Brazil. With immunization programs, continuous monitoring of rotavirus types is important to detect novel and emerging strains.
Assuntos
Gastroenterite/epidemiologia , Infecções por Rotavirus/epidemiologia , Adolescente , Adulto , Brasil/epidemiologia , Criança , Pré-Escolar , Genótipo , Humanos , Lactente , Recém-Nascido , Rotavirus/classificação , Infecções por Rotavirus/virologia , Estações do AnoRESUMO
The purpose of this study was to characterize astrovirus in faecal samples collected from children with and without diarrhea in São Paulo, Brazil, grouped into two sets: EPM and HU. Detection and genotyping were carried out using reverse transcription nested polymerase chain reaction (RT-PCR) with specific primers directed towards the genome open reading frame 2 (ORF2). Results for EPM set showed that 66/234 (28.2 percent) were positive: 28/94 (29.7 percent) from children with acute diarrhea, 14/45 (31.1 percent) with persistent diarrhea, and 9/55 (16.3 percent) from control individuals. No data was available for 15/40 (37.5 percent) of samples. Mixed infections with other viruses were found in 33 samples. In the HU, 18/187 (9.6 percent) were positive: 12/158 (7.6 percent) from individuals with acute diarrhea and 6/29 (20.7 percent) from control children. Four samples were mixed with other viruses. Out of 66 astrovirus positive EPM samples, 18 (27.2 percent) were characterized as human astrovirus type-1 (HAstV-1), two (3.0 percent) as HAstV-2, two (3.0 percent) as HAstV-3, and three (4.5 percent) as HAstV-8. Among 18 astrovirus positive HU samples, one (5.5 percent) was characterized as HAstV-1, six (33.3 percent) as HAstV-2, and one (5.5 percent) as HAstV-8. Two HAstV-8 genotyped samples were further confirmed by nucleotide sequencing. Our results shows that astroviruses are circulating in a constant manner in the population, with multiple serotypes, in higher frequency than it was described for other Brazilian regions. For the first time in Sao Paulo, Brazil, it was shown that astroviruses play an important role in children gastroenteritis, as described for most locations where they were detected.
Assuntos
Criança , Humanos , Infecções por Astroviridae/virologia , Gastroenterite/virologia , Mamastrovirus/genética , Doença Aguda , Infecções por Astroviridae/diagnóstico , Infecções por Astroviridae/epidemiologia , Brasil/epidemiologia , Estudos de Casos e Controles , Fezes/virologia , Genótipo , Gastroenterite/diagnóstico , Gastroenterite/epidemiologia , Mamastrovirus/isolamento & purificação , Fases de Leitura Aberta , Reação em Cadeia da Polimerase Via Transcriptase Reversa , RNA Viral/genéticaRESUMO
A total of 123 stool specimens collected in Teresina, Piauí between 1994 and 1996, from 0 to 2-year-old children with diarrhea, were used for this study. Molecular characterization of the G and P rotavirus genotypes was performed using the reverse transcriptase polymerase chain reaction. The following results were obtained for the P genotypes: P[8] (17. 1%), P[1] (4. 9%), P[4] (3. 3%), P[6, M37] (2. 4%) and mixtures (27. 6%). The P[1]+P[8] mixture was found in 19. 5% of the samples. For the G genotypes, the results were: G1 (25. 2%), G5 (13. 8%), G2 (2. 5%), G4 (2. 5%), G9 (0. 8%) and mixtures (41. 5%). G1+G5 was the mixture most frequently found (12. 1%). Our results showed unusual combinations such as P[1]G5 and P[1]+P[8]G5. The high percentage of mixtures and unusual combinations containing mixtures of human and animal rotavirus genotypes strongly suggests the possibility of gene reassortment and interspecies transmission.