RESUMO
Worldwide human astroviruses (HAstV) have increasingly been recognized as causative agents of viral gastroenteritis, mainly in infants and young children. The aim of this study was to assess the epidemiology and genotype diversity of HAstVs detected in children who participated in a trial in Belém, Brazil with the rhesus human reassortant rotavirus vaccine tetravalent (RRV-TV). From April/1990 to August/1992, 624 diarrheic stool samples were tested by enzyme immunoassay (EIA) for HAstV, with a positive rate of 4.0%. Reverse transcription-polymerase chain reaction (RT-PCR) was done in 129 samples (25 positive and 104 with twice the optical density (OD) value of negative control by EIA) being 33 positive. The overall positivity yielded by both methods was 5.4% (34/624). Genotyping of the 33 positive samples was done by type-specific RT-PCR and confirmed by sequence analysis. Phylogenetic analysis was performed using a 348-bp fragment of the ORF2 region of the capsid gene. HAstV-1 was the most prevalent, accounting for 45.5% of the isolates, followed by HAstV-2 (27.3%), HAstV-3 (12.1%), HAstV-4 (12.1%), and HAstV-6 (3.0%). The monthly distribution showed that HAstV-1 was predominant in the first year of study (May/1990 to May/1991) with highest prevalence in January/1991. HAstV-2 was predominant from July to November/1991 and HAstV-4 from September to October/1990. At 24 months of age, 30.6% of children had been infected by HAstV. The clinical symptoms registered during HAstV associated-diarrhea were usually mild. These data highlight the circulation of the different HAstV genotypes in Belém during the study period.
Assuntos
Infecções por Astroviridae/epidemiologia , Mamastrovirus/genética , Epidemiologia Molecular , Doença Aguda , Infecções por Astroviridae/virologia , Brasil/epidemiologia , Proteínas do Capsídeo/genética , Estudos de Casos e Controles , Pré-Escolar , Estudos de Coortes , Diarreia Infantil/epidemiologia , Diarreia Infantil/virologia , Fezes/virologia , Humanos , Incidência , Lactente , Fases de Leitura Aberta/genética , Filogenia , Kit de Reagentes para Diagnóstico , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Estações do Ano , Especificidade da EspécieRESUMO
Human astroviruses (HAstV) have been increasingly identified as important etiological agents of acute gastroenteritis in children up to five years old. The aim of this study was to determine the prevalence and genotype diversity of HAstV in children with symptomatic and asymptomatic infections in São Luís, Maranhão, Brazil. From June 1997 to July 1999 a total of 183 fecal samples 84 from symptomatic and 99 from asymptomatic children were tested by enzyme immunoassay for HAstV. Prevalence rates were found to be 11 and 3% for symptomatic and asymptomatic children, respectively. Reverse transcription-polymerase chain reaction (RT-PCR) was carried out in 46 specimens (26 symptomatic and 20 asymptomatic) including the 12 samples that were positive by enzyme immunoassay (EIA). The overall positivity yielded by both methods was 8% (15/184); of these, 11% (9/84) for symptomatic and 5% (5/99) for those without symptoms or signs. Sequence analysis of amplicons revealed that HAstV-1 genotype was the most prevalent, accounting for 60% of isolates. Genotypes 2, 3, 4, and 5 were also detected, as one single isolate (10%) for each type. Variations in the sequences were observed when Brazilian isolates were compared to prototype strains identified in the United Kingdom. No seasonal pattern of occurrence was observed during these two years of study, and peak detection rate was observed in children aged between 3 and 6 months in the symptomatic group, and between 18 and 24 months in the controls.
Assuntos
Infecções por Astroviridae/epidemiologia , Diarreia Infantil/virologia , Gastroenterite/virologia , Variação Genética , Doença Aguda , Brasil/epidemiologia , Estudos de Casos e Controles , Pré-Escolar , Diarreia Infantil/epidemiologia , Fezes/virologia , Feminino , Gastroenterite/epidemiologia , Genótipo , Humanos , Lactente , Recém-Nascido , Masculino , Mamastrovirus/genética , Mamastrovirus/isolamento & purificação , Filogenia , Prevalência , RNA Viral/genéticaRESUMO
Worldwide human astroviruses (HAstV) have increasingly been recognized as causative agents of viral gastroenteritis, mainly in infants and young children. The aim of this study was to assess the epidemiology and genotype diversity of HAstVs detected in children who participated in a trial in Belem, Brazil with the rhesus human reassortant rotavirus vaccine tetravalent (RRV-TV). From April/1990 to August/1992, 624 diarrheic stool samples were tested by enzyme immunoassay (EIA) for HAstV, with a positive rate of 4.0 per cent. Reverse transcription-polymerase chain reaction (RT-PCR) was done in 129 samples (25 positive and 104 with twice the optical density (OD) value of negative control by EIA) being 33 positive. The overall positivity yielded by both methods was 5.4 per cent (34/624). Genotyping of the 33 positive samples was done by type-specific RT-PCR and confirmed by sequence analysis. Phylogenetic analysis was performed using a 348-bp fragment of the ORF2 region of the capsid gene. HAstV-1 was the most prevalent, accounting for 45.5 per cent of the isolates, followed by HAstV-2 (27.3 per cent), HAstV-3 (12.1 per cent), HAstV-4 (12.1 per cent), and HAstV-6 (3.0 per cent). The monthly distribution showed that HAstV-1 was predominant in the first year of study (May/1990 to May/1991) with highest prevalence in January/1991. HAstV-2 was predominant from July to November/1991 and HAstV-4 from September to October/1990. At 24 months of age, 30.6 per cent of children had been infected by HAstV. The clinical symptoms registered during HAstV associated-diarrhea were usually mild. These data highlight the circulation of the different HAstV genotypes in Belem during the study period. J. Med. Virol. 79:530-538, 2007. (c) 2007 Wiley-Liss, Inc....(AU)
Assuntos
Masculino , Feminino , Criança , Humanos , Mamastrovirus , Infecções por Astroviridae/epidemiologia , Vacinas contra Rotavirus , Variação Genética , Reação em Cadeia da Polimerase , Diarreia/virologia , GastroenteriteRESUMO
Human astroviruses (HAstV) have been increasingly identified as important etiological agents of acute gastroenteritis in children up to five years old. The aim of this study was to determine the prevalence and genotype diversity of HAstV in children with symptomatic and asymptomatic infections in São Luís, Maranhão, Brazil. From June 1997 to July 1999 a total of 183 fecal samples 84 from symptomatic and 99 from asymptomatic children were tested by enzyme immunoassay for HAstV. Prevalence rates were found to be 11 and 3 percent for symptomatic and asymptomatic children, respectively. Reverse transcription-polymerase chain reaction (RT-PCR) was carried out in 46 specimens (26 symptomatic and 20 asymptomatic) including the 12 samples that were positive by enzyme immunoassay (EIA). The overall positivity yielded by both methods was 8 percent (15/184); of these, 11 percent (9/84) for symptomatic and 5 percent (5/99) for those without symptoms or signs. Sequence analysis of amplicons revealed that HAstV-1 genotype was the most prevalent, accounting for 60 percent of isolates. Genotypes 2, 3, 4, and 5 were also detected, as one single isolate (10 percent) for each type. Variations in the sequences were observed when Brazilian isolates were compared to prototype strains identified in the United Kingdom. No seasonal pattern of occurrence was observed during these two years of study, and peak detection rate was observed in children aged between 3 and 6 months in the symptomatic group, and between 18 and 24 months in the controls.
Assuntos
Recém-Nascido , Lactente , Pré-Escolar , Humanos , Masculino , Feminino , Infecções por Astroviridae/epidemiologia , Diarreia Infantil/virologia , Variação Genética , Gastroenterite/virologia , Mamastrovirus , Doença Aguda , Sequência de Bases , Brasil/epidemiologia , Estudos de Casos e Controles , Diarreia Infantil/epidemiologia , Fezes/virologia , Genótipo , Gastroenterite/epidemiologia , Técnicas Imunoenzimáticas , Mamastrovirus , Filogenia , Prevalência , Reação em Cadeia da Polimerase Via Transcriptase Reversa , RNA Viral/genética , Análise de Sequência de RNARESUMO
Human astroviruses (HAstV) have been increasingly identified as important etiological agents of acute gastroenteritis in children up to five years old. The aim of this study was to determine the prevalence and genotype diversity of HAstV in children with symptomatic and asymptomatic infections in São Luís, Maranhão, Brazil. From June 1997 to July 1999 a total of 183 fecal samples 84 from symptomatic and 99 from asymtomatic children were tested by enzyme immunoassay for HAstV. Prevalence rates were found to be 11 and 3% for symptomatic and asymptomatic children, respectively. Reverse transcription-polymerase chain reaction (RT-PCR) was carried out in 56 specimens (26 symptomatic and 20 asymptomatic) including the 12 samples that were positive by enzyme immunoassay (EIA). The overall positivity yelded by booth methods was 8% (15/184); of these, 11% (9/84) for symptomatic and 5% (5/99) for those without symptoms or signs. Sequence analysis of amplicons revealed that HAstV-1 genotype was the most prevalent, accounting for 60% of isolates. Genotypes 2, 3, 4, and 5 were also detected, as one single isolate (10%) for each type. Variations in the sequences were observed when Brazilian isolates were compared to prototype strains identified in the United Kingdom. No seasonal pattern of occurence was observed during these two years of study, and peak detection rate was observed in children aged between 3 and 6 months in the symptomatic group, and between 18 and 24 months in the controls...(AU)
Assuntos
Humanos , Criança , Mamastrovirus/classificação , Mamastrovirus/patogenicidade , Infecções por Astroviridae/diagnóstico , Infecções por Astroviridae/epidemiologia , Infecções por Astroviridae/etiologia , Gastroenterite/diagnóstico , Diarreia InfantilRESUMO
Human astroviruses (HAstV) have been increasingly identified as important etiological agents of acute gastroenteritis in children up to five years old. The aim of this study was to determine the prevalence and genotype diversity of HAstV in children with symptomatic and asymptomatic infections in São Luís, Maranhão, Brazil. From June 1997 to July 1999 a total of 183 fecal samples 84 from symptomatic and 99 from asymtomatic children were tested by enzyme immunoassay for HAstV. Prevalence rates were found to be 11 and 3% for symptomatic and asymptomatic children, respectively. Reverse transcription-polymerase chain reaction (RT-PCR) was carried out in 56 specimens (26 symptomatic and 20 asymptomatic) including the 12 samples that were positive by enzyme immunoassay (EIA). The overall positivity yelded by booth methods was 8% (15/184); of these, 11% (9/84) for symptomatic and 5% (5/99) for those without symptoms or signs. Sequence analysis of amplicons revealed that HAstV-1 genotype was the most prevalent, accounting for 60% of isolates. Genotypes 2, 3, 4, and 5 were also detected, as one single isolate (10%) for each type. Variations in the sequences were observed when Brazilian isolates were compared to prototype strains identified in the United Kingdom. No seasonal pattern of occurence was observed during these two years of study, and peak detection rate was observed in children aged between 3 and 6 months in the symptomatic group, and between 18 and 24 months in the controls...(AU)