ABSTRACT
Sapovirus (SaV) is an important pathogen of human acute gastroenteritis. A gastroenteritis outbreak occurred at a wedding hall in October 2007 in Ehime Prefecture, Japan. One hundred nine people who had either attended wedding parties or had eaten a box lunch at a conference held at the same hall complained of gastroenteritis symptoms. Among these 109 people, stool specimens from 56 patients were available for pathogen screening, and 20 (35.7%) of these specimens were positive for SaV, of whom 18 showed symptoms. The numbers of cDNA copies of the specimens ranged from 2.36 x 10(6) to 3.03 x 10(10) for symptomatic patients, and 2.19 x 10(6) and 1.18 x 10(9) per gram of stool for two asymptomatic food handlers. The incubation periods of the 18 symptomatic patients ranged from 14.5 to 99.5 hr. Identical nucleotide sequence types of SaV; that is, a single synonymous nucleotide difference (transition) or microheterogeneity, was detected in stool specimens from the symptomatic patients and the asymptomatic food handlers, with the direct nucleotide sequence of approximately 2.3 kb 3' end of the genome. Based on the phylogenetic analysis with the complete capsid nucleotide sequence, these strains were clustered into genogroup IV. This outbreak was thought to be caused by a single source, and underscores the importance of proper hygiene in the environment and/or in food-handling practices to control SaV outbreaks.
Subject(s)
Caliciviridae Infections/epidemiology , Caliciviridae Infections/virology , Disease Outbreaks , Gastroenteritis/epidemiology , Gastroenteritis/virology , Sapovirus/classification , Sapovirus/genetics , Adolescent , Adult , Aged , Capsid Proteins/genetics , Child , Child, Preschool , Cluster Analysis , Feces/virology , Female , Humans , Japan/epidemiology , Male , Middle Aged , Molecular Sequence Data , Phylogeny , Polymorphism, Genetic , RNA, Viral/genetics , Sapovirus/isolation & purification , Sequence Analysis, DNA , Sequence Homology , Viral Load , Young AdultSubject(s)
Caliciviridae Infections/epidemiology , Disease Outbreaks , Gastroenteritis/epidemiology , Molecular Epidemiology/methods , Sapovirus/genetics , Caliciviridae Infections/virology , Child , Child, Preschool , Data Interpretation, Statistical , Female , Gastroenteritis/virology , Genome, Viral , Humans , Infant , Japan/epidemiology , Male , Phylogeny , Polymerase Chain Reaction , Population Surveillance , RNA, Viral/analysis , Sequence Analysis, RNAABSTRACT
An outbreak of gastroenteritis occurred at a kindergarten in Yokote City, Japan, between February 2006 and March 2006. Sapovirus was identified in 19 of 26 stool specimens by reverse transcription-PCR. A high viral shedding pattern was found for this strain, which was shown to be antigenically distinct from other genogroups.
Subject(s)
Caliciviridae Infections/epidemiology , Caliciviridae Infections/virology , Disease Outbreaks , Gastroenteritis/epidemiology , Gastroenteritis/virology , Sapovirus/isolation & purification , Adult , Child , Child, Preschool , Feces/virology , Female , Humans , Japan/epidemiology , Male , Phylogeny , RNA, Viral/analysis , RNA, Viral/genetics , Reverse Transcriptase Polymerase Chain Reaction , Sapovirus/classification , Sequence Homology , Virus SheddingABSTRACT
Sapovirus (SV), which causes gastroenteritis in humans, is composed of genetically divergent viruses classified into 5 genogroups. In this study, 2.2-kb nucleotide sequences of the 3' terminus of the genome of 15 SV strains detected in Japan were determined. The 15 SV strains could be classified into four genogroups (GI, GII, GIV and GV), and in two of these, GI and GII, 10 genotypes were identified. The amino acid sequences of the central variable region of the capsid protein showed less than 81% identity when strains belonging to different genotypes were compared. It was therefore supposed that antigenic variety exists between different genotypes. These results will be useful for further genetic and antigenic analyses of SV.
Subject(s)
Capsid Proteins/genetics , Genetic Variation , Sapovirus/genetics , Sapovirus/immunology , Antigenic Variation , Base Sequence , Japan , Molecular Sequence Data , Phylogeny , Sapovirus/classification , Sequence AlignmentABSTRACT
Human noroviruses (NoVs), members of the genus Norovirus in the family Caliciviridae, are the leading agents of nonbacterial acute gastroenteritis worldwide. Human NoVs are currently divided into at least two genogroups, genogroup I (GI) and genogroup II (GII), each of which contains at least 14 and 17 genotypes. To explore the genetic and antigenic relationship among NoVs, we expressed the capsid protein of four genetically distinct NoVs, the GI/3 Kashiwa645 virus, the GII/3 Sanbu809 virus, the GII/5 Ichikawa754 virus, and the GII/7 Osaka10-25 virus in baculovirus expression system. An antigen enzyme-linked immunosorbent assay (ELISA) with hyperimmune serum against the four recombinant capsid proteins and characterized previously three capsid proteins derived from GI/1, GI/4, and GII/12 was developed to detect the NoVs antigen in stools. The antigen ELISA was highly specific to the homotypic strains, allowing assignment of a strain to a Norovirus genetic cluster within a genogroup.
Subject(s)
Antigens, Viral/analysis , Feces/virology , Norovirus/isolation & purification , Animals , Antigens, Viral/biosynthesis , Antigens, Viral/genetics , Baculoviridae/genetics , Baculoviridae/metabolism , Caliciviridae Infections/diagnosis , Capsid Proteins/analysis , Capsid Proteins/biosynthesis , Capsid Proteins/genetics , Enzyme-Linked Immunosorbent Assay/methods , Gastroenteritis/diagnosis , Humans , Norovirus/genetics , Norovirus/immunology , Phylogeny , Recombinant Proteins/biosynthesisABSTRACT
In a survey on the etiology of acute gastroenteritis in infants and young children in Nigeria, group C human rotaviruses were detected in two of 112 rotavirus positive stool specimens collected between 1999 and 2000. The VP7, VP6, and VP4 genes of the two Nigerian human group C rotavirus strains (Jajeri and Moduganari) were sequenced in this study. Comparative sequence analysis with other published human group C rotaviruses showed that the genes encoding the three structural proteins were remarkably conserved in primary structure with few mutations. The VP4 and VP7 genes from the two Nigerian strains were related more closely to each other than to those of other published strains, and formed a separate cluster on the phylogenetic tree. In contrast, it was of note that VP6 gene of strain Moduganari was related more closely to the Brazilian strain Belem than to the other Nigerian strain Jajeri. This is the first report of identification of human group C rotavirus in Nigeria and constitutes the first sequence data of human group C rotaviruses in the African continent.
