RESUMO
The present study aimed to describe the epidemiological characteristics of norovirus (NoV) associated with sporadic gastroenteritis in regional populations of Nara Prefecture, Japan, from the 2006/2007 to 2011/2012 epidemic season. Fecal specimens of sporadic gastroenteritis collected between September 2006 and August 2012 in Nara Prefecture were examined for the presence of NoV by reverse transcription-polymerase chain reaction. The NoV genotype was determined by nucleotide sequence analysis. In total, 274 NoVs associated with sporadic gastroenteritis were identified. We detected 10 different NoV genotypes: GI/3, GI/4, GI/8, GII/2, GII/3, GII/4, GII/6, GII/7, GII/12, and GII/13. A high NoV detection rate of 35.9% was identified in 1-year-old children. Among the 274 NoV isolates, 142 were obtained from males and 131 were obtained from females (the source of one was unknown). The most prevalent genotype was GII/4, accounting for 117 of the 192 different NoVs identified by sequencing. More epidemiological data will be required to determine the epidemiological characteristics of NoVs in other areas of Japan.
Assuntos
Infecções por Caliciviridae/epidemiologia , Gastroenterite/epidemiologia , Norovirus/classificação , Norovirus/genética , Adolescente , Infecções por Caliciviridae/virologia , Criança , Pré-Escolar , Fezes/virologia , Feminino , Gastroenterite/virologia , Genótipo , Humanos , Lactente , Recém-Nascido , Japão/epidemiologia , Masculino , Dados de Sequência Molecular , Norovirus/isolamento & purificação , RNA Viral/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Análise de Sequência de DNARESUMO
We examined the incidence of amantadine-resistant influenza AH3 viruses isolated in Nara Prefecture during the 2005-06 winter season. The genetic analyses of the M2 ion channel protein were conducted using reverse transcriptase PCR and direct sequencing. Thirteen out of 18 (72.2%) strains were identified as amantadine-resistant, and this incidence was remarkably higher than those previously recored in Nara Prefecture. Genetic analyses of the viruses revealed that all the anti-drug strains contained a change at position 31 (AGT-->AAT, Ser31Asn) in the M2 gene. One of the 13 amantadine-resistant strains also contained a change at position 27 (GTT-->GCT, Val27Ala). Our data indicate that there has been a significant increase of drug-resistant influenza AH3 viruses in Nara Prefecture, and raise concern about the spread of resistant influenza AH3 viruses in Japan.
Assuntos
Amantadina/farmacologia , Vírus da Influenza A/efeitos dos fármacos , Influenza Humana/virologia , Farmacorresistência Viral , Humanos , Vírus da Influenza A/genética , Vírus da Influenza A/isolamento & purificação , Influenza Humana/epidemiologia , Japão/epidemiologia , Mutação Puntual , Proteínas da Matriz Viral/genéticaRESUMO
The current study elucidated the epidemiological characteristics of sapovirus (SaV) and human astrovirus (HAstV) associated with gastroenteritis among children in regional populations of Nara Prefecture, Japan, during the 2009/2010-2014/2015 seasons. The SaV detection rate was 7.5% (71/948) according to reverse transcription-polymerase chain reaction. A high SaV detection rate of 13.5% was observed among children 4 years of age. The highest SaV detection rate was observed in June (19.2%), followed by July (11.1%). The detected SaV included 7 genotypes: GI.1, GI.2, GII.3, GII.1, GI.3, GII.2, and GV, in order of decreasing prevalence. In comparison, the HAstV detection rate was 4.2% (40/948). The HAstV detection rate among children 4 years of age was 12.2%. The HAstV detection rate was highest in July (13.9%), followed by May (10.5%) and August (6.7%). The detected HAstVs included genotypes 1, 4, 6, and 8. The most prevalent genotype was 1, followed by 4 and 8. This report provides an epidemiological overview of SaV and HAstV infection in Nara Prefecture, Japan.
Assuntos
Infecções por Astroviridae/epidemiologia , Infecções por Caliciviridae/epidemiologia , Gastroenterite/epidemiologia , Mamastrovirus/isolamento & purificação , Sapovirus/isolamento & purificação , Adolescente , Infecções por Astroviridae/virologia , Infecções por Caliciviridae/virologia , Criança , Pré-Escolar , Feminino , Gastroenterite/virologia , Genótipo , Humanos , Lactente , Recém-Nascido , Japão/epidemiologia , Masculino , Mamastrovirus/classificação , Mamastrovirus/genética , Prevalência , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sapovirus/classificação , Sapovirus/genética , Estações do AnoRESUMO
We investigated the frequency of amantadine-resistant influenza A viruses in Nara Prefecture during four epidemic seasons from 2001-02 to 2004-05. Point mutations within the M2 gene were identified using RT-PCR and DNA sequencing analysis. Five viruses (3.4%) with point mutation were observed from 145 strains analyzed. Three viruses (2.0%) possessed a change at position 31 (AGT-->AAT, Ser to Asn), one virus (0.7%) showed a change at position 26 (CTT-->TTT, Leu to Phe), one virus (0.7%) showed a change at position 27 (GTT-->ATT, Val to Ile), and none showed a change at position 30. All of these changes were the transition type of mutation. These results indicated that the possible circulation of drug-resistant viruses to the community was not supported by the findings obtained during the 2004-05 season in Nara.
Assuntos
Amantadina/farmacologia , Antivirais/farmacologia , Surtos de Doenças , Farmacorresistência Viral , Vírus da Influenza A Subtipo H3N2/efeitos dos fármacos , Influenza Humana/virologia , Substituição de Aminoácidos/genética , Animais , Linhagem Celular , Cães , Humanos , Vírus da Influenza A Subtipo H3N2/genética , Vírus da Influenza A Subtipo H3N2/isolamento & purificação , Influenza Humana/epidemiologia , Japão/epidemiologia , Mutação Puntual , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Proteínas da Matriz Viral/genéticaAssuntos
Fezes/virologia , Gastroenterite/epidemiologia , Norovirus/genética , Norovirus/isolamento & purificação , Infecções por Caliciviridae/epidemiologia , Infecções por Caliciviridae/genética , Infecções por Caliciviridae/virologia , Gastroenterite/genética , Gastroenterite/virologia , Genes , Humanos , Japão/epidemiologia , Norovirus/classificação , Filogenia , Reação em Cadeia da Polimerase , Análise de SequênciaRESUMO
We examined the incidence of oseltamivir-resistant seasonal A(H1N1) and A(H1N1)pdm09 influenza viruses from the 2007/2008 to 2012/2013 season in Nara Prefecture, Japan. To detect the oseltamivir resistance marker in neuraminidase (NA), 365 influenza viruses (60 seasonal A(H1N1) and 305 A(H1N1)pdm09) were sequenced. The H275Y mutation in the NA gene, which confers resistance to oseltamivir, was identified in 93.8% (30/32) of seasonal A(H1N1) viruses that were circulating during the 2008/2009 season. Moreover, the detection rate of oseltamivir-resistant A(H1N1)pdm09 viruses was 4.1% (3/74) and 2.8% (5/180) in the 2009/2010 and 2010/2011 season, respectively. Four cases of oseltamivir-resistant A(H1N1)pdm09 virus infection occurred in the same hematology ward during the 2010/2011 season. Our data show a low frequency of oseltamivir-resistant A(H1N1)pdm09 virus in Nara Prefecture but suggested the possibility of human-to-human transmission of this virus.