Objective: To understand the epidemiological and etiological characteristics of outbreaks on acute gastroenteritis caused by sapovirus (SaV) worldwide. Methods: Literature about the outbreaks on acute gastroenteritis caused by SaV were retrieved from the databases including WanFang, CNKI, PubMed and Web of Science after evaluation. Time, geography, setting and population distributions of outbreaks, transmission mode, SaV genotype and clinical characteristics of the patients were analyzed. Results: A total of 34 papers about SaV were included, involving 146 outbreaks occurred between October 1976 and April 2016. In these papers, 138 outbreaks were reported on the related months. All these outbreaks occurred in northern hemisphere. SaV outbreaks occurred all year around, but mainly in cold season, the incidence was highest in December (25 outbreaks) and lowest in in August (2 outbreaks). Most outbreaks were reported by Japan, followed by Canada, the United States of America and the Netherlands. There were 141 outbreaks for which the occurring settings were reported, child-care settings were most commonly reported setting (48/141, 34.04%), followed by long-term care facility (41/141, 29.08%) and hospital (16/141, 11.35%). Clinical symptoms of 1 704 cases in 31 outbreaks were reported, with the most common symptom was diarrhea (1 331/1 704, 78.12%), followed by nausea (829/1 198, 69.20%), abdominal pain (840/1 328, 63.25%), vomiting (824/1 704, 48.36%) and fever (529/1 531, 34.53%). Genotypes of SaV were determined for 119 outbreaks. GⅠ(51/119, 42.86%) and GⅣ (45/119, 37.82%) were predominant. The outbreaks of GⅣ SaV increased suddenly in 2007, and the outbreaks of GⅠ SaV mainly occurred in 2008 and during 2011-2013. Conclusions: SaV outbreaks were reported mainly by developed countries, with most outbreaks occurred in cold season, in child-care settings and long term care facility. GⅠ and GⅣ were the most common genotypes of SaV. Prevention and control of SaV outbreak in China seemed relatively weak, and it is necessary to conduct related training and to strengthen the SaV outbreak surveillance in areas where service is in need.
Caliciviridae Infections/virology* ; Child ; China/epidemiology* ; Disease Outbreaks ; Feces/virology* ; Gastroenteritis/virology* ; Genotype ; Humans ; Phylogeny ; RNA, Viral/genetics* ; Sapovirus/isolation & purification* ; Sequence Analysis, DNA

Objective: To analyze the genetic characterization of norovirus isolated in an outbreak of gastroenteritis in Jiangsu province. Methods: Extracted viral RNA from the swab samples of cases of acute gastroenteritis outbreak in Jiangsu province on December 16-27, 2016 was reversely transcribed to cDNA, and partial RNA-dependent RNA polymerase sequence and complete capsid sequence (VP1) were amplified by RT-PCR. Amplification products were sequenced for the analysis of genetic characteristics. Results: Based on sequence alignment, the variant shared a high level of identity with the strain GⅡ.g isolated in Spain and Finland (98.7%) in the RNA-dependent RNA polymerase region, and with the strain GⅡ.1 isolated in American (99.4%) in the VP1. The recombination was determined by using software Simplot, and the breakpoint of recombination was located in the ORF1/2 overlap region at position 5 106 of VP1. The result of amino acids alignment in capsid region showed that there were no mutations in the amino acids of the predicted epitopes and receptor binding site Ⅰ-Ⅲ, but a unique amino acid change was detected at position 132 (N-S). Conclusion: The norovirus isolated in the outbreak of gastroenteritis in Jiangsu province was a rare recombinant norovirus variant GⅡ.g-GⅡ.1.
Caliciviridae Infections/epidemiology* ; Capsid Proteins ; Disease Outbreaks ; Gastroenteritis/epidemiology* ; Genotype ; Humans ; Norovirus/isolation & purification* ; Phylogeny ; RNA, Viral/genetics* ; Reverse Transcriptase Polymerase Chain Reaction ; Sequence Analysis, DNA

OBJECTIVETo monitor the epidemiology of norovirus infection in diarrheal children in Shanghai between 2009 and 2011 and characterize the genotypes of norovirus strains.

METHODThe stool samples were collected from children visiting outpatient clinic for acute non-dysenteric diarrhea between 2009 and 2011.One step real-time RT-PCR was used for screening norovirus genogroups GI and GII. The genotypes of norovirus genogroup GII were classified based on the nucleotide sequences of both partial capsid and polymerase fragments.

RESULTA total of 2 288 outpatient children with acute diarrhea were included in this study, out of whom, 531 (23.1%) were positive for norovirus in the fecal specimens based on real-time RT-PCR test.Norovirus was prevalent throughout the year and an increased activity of norovirus infection was usually observed between July and October. Children <4 years of age accounted for 95.2% of norovirus-infected cases, and the detection rate of norovirus was significantly higher in diarrheal children <4 years than in those ≥ 4 years (24.4% vs. 10.7%,χ(2) = 10.66, P < 0.05).Of 531 norovirus-positive specimens, 4 (1.7%) were positive for genogroup GI and 527 (98.3%) positive for genogroup GII. Seven distinct capsid genotypes were identified in 234 norovirus strains, including 153 (64.4%) GII.4 (9 belonging to 2010 variants and 145 belonging to 2006b variants), 66 (27.6%) GII.3, 7 (2.9%) GII.2, 6 (2.5%) GII.6, 4 (1.7%) GII.12, 1 (0.4%) GII.7 and GII.14 in each. Seven polymerase genotypes were identified in 244 norovirus strains, including 189 (77.5%) GII.4 (14 belonging to 2010 variants and 175 belonging to 2006b variants), 47 (19.3%) GII.12, 2 (0.8%) GII.16, GII.b and GII.g in each, 1 (0.4%) GII.2 and GII.6 in each. A new GII.4-2010 (New Orleans) variant was first detected in June 2010 and sporadically circulated afterwards.Of 198 norovirus strains in which both polymerase and capsid genotypes were determined, 56 showed discordant results, indicating potential norovirus recombinants. The common discordant combinations of the polymerase and capsid genotypes were GII.12/GII.3 (69.6%) and GII.4/GII.3 (8.9%).

CONCLUSIONNorovirus is a common causative agent responsible for diarrhea in Shanghai children over the three years and norovirus-associated diarrhea was epidemic year round with high activity in late summer and autumn in Shanghai.Infants and young children are susceptible to norovirus infection. The circulating norovirus showed genetic diversity. The GII.4-2006b variant continued to predominate in Shanghai during the period of 2009-2011 despite the emergence of the novel GII.4-2010 (New Orleans) variant.

Adolescent ; Caliciviridae Infections ; epidemiology ; virology ; Capsid Proteins ; genetics ; Child ; Child, Preschool ; China ; epidemiology ; Diarrhea ; epidemiology ; virology ; Feces ; virology ; Female ; Gastroenteritis ; epidemiology ; virology ; Genetic Variation ; Genotype ; Humans ; Infant ; Male ; Molecular Epidemiology ; Norovirus ; classification ; genetics ; isolation & purification ; Prevalence ; RNA, Viral ; genetics ; isolation & purification ; Reverse Transcriptase Polymerase Chain Reaction ; Sequence Analysis, DNA

OBJECTIVETo investigate the molecular epidemiological characteristics of norovirus in Guangzhou from 2009 to 2011.

METHODSA total of 183 water samples, 1162 seafood samples and 1066 diarrhea stool specimens were collected from January 2010 to May 2011, June 2009 to June 2011 and July 2009 to December 2010 respectively in Guangzhou. Norovirus was detected by real time reverse transcript-PCR (qRT-PCR). The partial polymerase gene was amplified from norovirus positive samples, then sequenced and compared with the sequences of norovirus in GenBank. The phylogenetic tree was created.

RESULTSThe positive rate was 19.67% (36/183), 8.26% (96/1162) and 37.05% (395/1066) in water samples, seafood and diarrhea patients respectively. Noroviruses from positive samples could be divided into 10 representative strains, in which 7 representative strains of genotype of 208 samples was type G2-4. The sequences from water, seafood and stool specimens were highly homologous with the similarity of 94% - 100%.

CONCLUSIONIn Guangzhou, the predominant Norovirus genotype was G2-4 and the positive rate of samples was high.

Base Sequence ; Caliciviridae Infections ; epidemiology ; virology ; China ; epidemiology ; Diarrhea ; virology ; Genotype ; Humans ; Molecular Epidemiology ; Norovirus ; classification ; genetics ; isolation & purification ; Phylogeny ; RNA, Viral ; genetics ; Seafood ; virology ; Water Microbiology

To describe the epidemiological characteristics of norovirus (NOV) associated acute gastroenteritis in Shanghai and characterize the evolution pattern of circulating strains. From March 2012 to February 2013, 502 stool specimens were collected from adult (> or = 16 years) outpatients who visited either of the two sentinel hospitals in Shanghai for acute gastroenteritis. Molecular detection and genotyping of NoV were performed and the phylogenetic relationship of the circulating strains has also been comprehensively analyzed. The epidemics level of GI NoV was low throughout the surveillance period, with the positive rate of 3.78% (19 cases), and no seasonality of GI NoV infection could be distinguished. For GII genogroup, higher epidemics in adults in Shanghai, with the detection rate of 17.13% (86 cases), were observed. And relatively high epidemics of GII NoV infection were spotted between October and December in 2012. The frequency of NoV associated acute gastroenteritis in older people is significantly higher than that in young individuals (P < 0.05). Sequencing and genotyping analysis revealed that the high epidemics of GII NoV infection between October and December in 2012 is associated with the emergence of a novel GII.4 norovirus strain, termed Sydney_2012. Sequence analysis also demonstrated that this was a recombinant virus between a GII.e polymerase and GII.4 capsid, which has also been the dominant circulating strain in Shanghai. In 2012, a new GII.4 variant, termed Sydney_2012, emerged in Shanghai and caused high epidemics of acute gastroenteritis during late autumn and winter.
Adolescent ; Adult ; Aged ; Caliciviridae Infections ; epidemiology ; virology ; China ; epidemiology ; Disease Outbreaks ; Female ; Gastroenteritis ; epidemiology ; virology ; Genotype ; Humans ; Male ; Middle Aged ; Norovirus ; chemistry ; classification ; genetics ; isolation & purification ; Phylogeny ; Viral Envelope Proteins ; chemistry ; genetics ; Young Adult

Caliciviridae Infections ; epidemiology ; virology ; Gastroenteritis ; virology ; Genetic Variation ; Genotype ; Humans ; Norovirus ; classification ; genetics

Norovirus (NV) has caused large outbreaks of gastroenteritis in schools. Studies of NV epidemiology in schools related to NV outbreaks have been frequently reported. However, reports of that in schools without outbreaks are not found. Presently, NV molecular epidemiology surveillance was carried out in asymptomatic food handlers working at nonoutbreak elementary schools in Incheon, Korea, in March, April and December, 2009. NV prevalence was examined by real-time reverse transcription-PCR (RT-PCR) and the positive products were re-evaluated by conventional RT-PCR for sequencing. Fecal samples (n = 776) were collected from 776 food handlers in 60 schools. NV was detected in 26 of them (3.4%). Of these, 17 (65%) were positive for NV GII and 10 (38%) were positive for NV GI. Of the 26 samples, 19 were positive by conventional RT-PCR. Sequencing of these 19 strains revealed GII/4 (n = 5), GI/6 (n = 3), GI/14 (n = 2), GII/8 (n = 2), GI/2 (n = 2), GI/10 (n = 1), GII/1 (n = 1), GII/3 (n = 1), GII/7 (n = 1), and GII/16 (n = 1). In this survey, the food handler population unrelated to NV outbreaks was found to normally contain asymptomatic carriers of NV. The excretion of NV from asymptomatic food handlers should be an infection source of NV outbreaks.
Adult ; Caliciviridae Infections/*epidemiology/genetics ; Feces/virology ; Female ; Food Handling ; Gastroenteritis/*epidemiology/genetics ; Genotype ; Humans ; Male ; Middle Aged ; Norovirus/genetics/*isolation & purification ; Prevalence ; RNA, Viral/analysis ; Republic of Korea ; Reverse Transcriptase Polymerase Chain Reaction ; Schools ; Sequence Analysis, RNA

In January 2008, an outbreak of acute gastroenteritis at a waterpark was reported to the Bundang-gu Public Health Center in Seongnam, Korea. To determine the etiological agent and mode of transmission, a retrospective cohort study was done using structured questionnaires and stool samples from patients who had current gastrointestinal symptoms and three food handlers were tested. A total of 67 (31.0%) students and teachers developed acute gastroenteritis. No food items were associated with an increased risk of the illness. Norovirus was detected in 3 stool specimens collected from 6 patients who had severe diarrhea using semi-nested RT-PCR. All the specimens contained the genogroup I strains of the norovirus. Norovirus was also detected in the groundwater samples from the waterpark. In the nucleotide sequencing analysis, all the genogroup I noroviruses from the patients and groundwater samples were identified as the norovirus genotype I-4 strain. They were indistinguishable by DNA sequencing with a 97% homology. We conclude the outbreak of acute gastroenteritis caused by the norovirus was closely related to the contaminated groundwater.
Adult ; Caliciviridae Infections/*epidemiology/*virology ; Child ; Cohort Studies ; *Disease Outbreaks ; Feces/virology ; Female ; Fresh Water/*virology ; Gastroenteritis/*epidemiology/*virology ; Genotype ; Humans ; Male ; Norovirus/classification/genetics/*isolation & purification ; Phylogeny ; Republic of Korea ; Retrospective Studies ; Reverse Transcriptase Polymerase Chain Reaction ; Sequence Analysis, RNA

In January 2008, an outbreak of acute gastroenteritis at a waterpark was reported to the Bundang-gu Public Health Center in Seongnam, Korea. To determine the etiological agent and mode of transmission, a retrospective cohort study was done using structured questionnaires and stool samples from patients who had current gastrointestinal symptoms and three food handlers were tested. A total of 67 (31.0%) students and teachers developed acute gastroenteritis. No food items were associated with an increased risk of the illness. Norovirus was detected in 3 stool specimens collected from 6 patients who had severe diarrhea using semi-nested RT-PCR. All the specimens contained the genogroup I strains of the norovirus. Norovirus was also detected in the groundwater samples from the waterpark. In the nucleotide sequencing analysis, all the genogroup I noroviruses from the patients and groundwater samples were identified as the norovirus genotype I-4 strain. They were indistinguishable by DNA sequencing with a 97% homology. We conclude the outbreak of acute gastroenteritis caused by the norovirus was closely related to the contaminated groundwater.
Adult ; Caliciviridae Infections/*epidemiology/*virology ; Child ; Cohort Studies ; *Disease Outbreaks ; Feces/virology ; Female ; Fresh Water/*virology ; Gastroenteritis/*epidemiology/*virology ; Genotype ; Humans ; Male ; Norovirus/classification/genetics/*isolation & purification ; Phylogeny ; Republic of Korea ; Retrospective Studies ; Reverse Transcriptase Polymerase Chain Reaction ; Sequence Analysis, RNA

To study the molecular characteristics of Noroviruses causing outbreaks of acute gastroenteritis in Huzhou. During April 2008 and February 2009, fecal specimens of patients collected from 2 outbreaks of acute gastroenteritis were tested for Norovirus by real-time RT-PCR. Partial sequence of RNA dependent RNA polymerase(RdRp) of the positive samples were amplified by RT-PCR, the PCR products were then purified, sequenced and phylogenetic analysis was conducted. Both genogroup II (GII) and genogroup I (GI) noroviruses were detected in 2 outbreaks. Phylogenetic analysis revealed that two of the GI norovirus strains isolated from 2008 belonged to genotype GI/2 and one of the GI Norovirus strain isolated from 2009 belonged to genotype GI/3. The other GIIú norovirus strains isolated from 2009 had high nucleotide identity with GIIb genotype that had been reported frequently in European countries during 2000 and 2001 and in Asian countries recently. These results suggested that the epidemic strains of norovirus isolated in Huzhou had a high degree of genetic diversity and prevalent genotypes at different times were also different. To our knowledge this is the first report of detecting GIIb variant in outbreaks of acute gastroenteritis in China.
Acute Disease ; Caliciviridae Infections ; epidemiology ; virology ; China ; epidemiology ; Disease Outbreaks ; Feces ; virology ; Gastroenteritis ; epidemiology ; virology ; Genotype ; Humans ; Norovirus ; classification ; genetics ; isolation & purification ; Phylogeny ; RNA, Viral ; genetics ; Sequence Homology, Nucleic Acid