precise characterization of norovirus (norwalk-like virus)-specific monoclonal antibodies with broad reactivity.we have been characterizing monoclonal antibodies against norovirus (norwalk-like virus). in the course of our study, two monoclonal antibodies generated against norovirus genogroup ii capsid protein were found to react not only to genogroup ii but also to genogroup i recombinant capsid proteins. in addition, we showed that these two monoclonal antibodies reacted to a 40-amino-acid-fragment located close to the n-terminal region of genogroup ii norovirus. similar reactivity was observed with the ...200312791850
detection of norovirus (gi, gii), sapovirus and astrovirus in fecal samples using reverse transcription single-round multiplex pcr.a reverse transcription (rt) single-round multiplex polymerase chain reaction (smpcr) assay was developed to detect simultaneously norovirus genogroup i and ii, sapovirus and astrovirus. a total of 377 diarrhea stool samples (screened for rotavirus- and adenorivus-negative) from four regions in japan during july 2000 to june 2001 were examined by rt-smpcr. the positive rate was 16.4% (62 out of 377 stool samples). norovirus, sapovirus and astrovirus were detected in 42, 16, 4 of 60 positive samp ...200314599677
recombinant virus-like particles of a norovirus (genogroup ii strain) administered intranasally and orally with mucosal adjuvants lt and lt(r192g) in balb/c mice induce specific humoral and cellular th1/th2-like immune responses.we investigated the immune response induced by mucosal immunization of balb/c mice with virus-like particles (vlps) of a genogroup ii norovirus, dijon171/96 virus, produced in the baculovirus system. vlps administered alone by the intranasal route induced a high serum antibody response as well as fecal iga, which were enhanced when the heat-labile escherichia coli toxin or its non toxic mutant lt(r192g) was coadministered. in these conditions, the oral route was also efficient. cytokine producti ...200415003634
[the norovirus-epidemic in berlin - clinic, epidemiology, and prevention].during the winter 2002/2003, an increased number of outbreaks of acute gastroenteritis caused by norovirus was reported from germany, some other european countries and the usa. in this study, the epidemiological and clinical features of the berlin norovirus outbreak were investigated in order to identify the reasons for the spread of norovirus gastroenteritis and possible control measures.200415095121
inter- and intragenus structural variations in caliciviruses and their functional implications.the family caliciviridae is divided into four genera and consists of single-stranded rna viruses with hosts ranging from humans to a wide variety of animals. human caliciviruses are the major cause of outbreaks of acute nonbacterial gastroenteritis, whereas animal caliciviruses cause various host-dependent illnesses with a documented potential for zoonoses. to investigate inter- and intragenus structural variations and to provide a better understanding of the structural basis of host specificity ...200415163740
comparison of coliforms and coliphages as tools for assessment of viral contamination in river water.the aim of the study was to evaluate the presence of pathogenic viruses in the moselle river and to compare the usefulness of thermotolerant coliforms and somatic coliphages as tools for river water quality assessment in terms of viral contamination. thermotolerant coliforms and somatic coliphages were enumerated by standardized methods in 170 samples of river water drawn from five sampling sites along the moselle river (eastern france). bgm cell culture and integrated cell culture-reverse trans ...200415184169
virus diversity and an outbreak of group c rotavirus among infants and children with diarrhea in maizuru city, japan during 2002-2003.a total of 236 fecal specimens collected from infants and children with gastroenteritis in maizuru city, japan from july 2002 to june 2003, were tested for the presence of rotaviruses, noroviruses, sapoviruses, astroviruses, and adenoviruses by rt-pcr, page, rpha, and latex agglutination methods. among diarrheal viruses detected, group a rotavirus was the most prevalent (32.2%; 76 of 236) followed by norovirus gii (21.2%; 50 of 236), group c rotavirus (10.2%; 24 of 236), adenovirus (3.8%; 9 of 2 ...200415258985
existence of multiple outbreaks of viral gastroenteritis among infants in a day care center in japan.a total of 921 fecal specimens collected from 44 infants in a day care center (dcc) in tokyo, japan during june 1999 to july 2000 were tested for the presence of rotavirus, norovirus, sapovirus, astrovirus and adenovirus by reverse-transcription-multiplex polymerase chain reaction (rt-multiplex pcr) and sequence analysis. of 88 fecal specimens from infants with acute gastroenteritis, 51.1% (45) were found to be positive for diarrheal viruses. astrovirus was the most prevalent (15.9%, 14 of 88), ...200515841336
calicivirus infection in human immunodeficiency virus seropositive children and adults.the importance of enteric viral infections in hiv-related diarrhea is uncertain. human caliciviruses have emerged as a leading cause of acute diarrhea worldwide.200515911425
a 5-year study of the prevalence and genetic diversity of human caliciviruses associated with sporadic cases of acute gastroenteritis in young children admitted to hospital in melbourne, australia (1998-2002).the prevalence and genetic diversity of human caliciviruses causing sporadic cases of acute gastroenteritis in young children hospitalized in a large pediatric hospital in melbourne, australia over 5 years (incorporating january 1998-december 2002) was studied by reverse transcription and sequence analysis of part of the polymerase gene. the overall prevalence of calicivirus infection in children aged <5 years during the 5 year study was 9.2% (113/1,233), with 95% of the strains belonging to the ...200516032716
development of a novel protocol for rt-multiplex pcr to detect diarrheal viruses among infants and children with acute gastroenteritis in eastern russia.viral gastroenteritis is one of the most common illnesses in humans worldwide and it has a great impact on people. recently, we reported three rt-multiplex pcr assays termed a, b and c that could detect three groups of diarrheal viruses; group a, b and c rotaviruses and adenovirus [phan et al., j med virol 2004; 74:173-9]; norovirus gi and gii, sapovirus and astrovirus [yan et al., j virol meth 2003; 114:37-44]; enteroviruses, hepatitis a and e viruses and influenza a virus [phan et al., arch vi ...200516122155
an outbreak of mixed infection of enterohemorrhagic escherichia coli o26:h11 and norovirus genogroup ii at a kindergarten in shimane, japan. 200516249634
development of an extraction and concentration procedure and comparison of rt-pcr primer systems for the detection of hepatitis a virus and norovirus gii in green onions.vegetables can be considered as a vector of transmission for human hepatic and enteric viruses such as hepatitis a virus (hav) and noroviruses when contaminated by spoiled irrigation water or when prepared by infected food handlers. recently, outbreaks of hav have been reported in the usa involving fresh green onions. a viral elution-concentration method was developed for the detection of hav and norovirus contaminated green onions by rt-pcr. repeated pipetting/washings of the surface with a ph ...200616423413
genetic diversity of noroviruses in taiwan between november 2004 and march 2005.noroviruses are a major health burden and are responsible for the majority of outbreaks of gastroenteritis in the world. human noroviruses can be genetically divided into two main genogroups (gi and gii) and subdivided into many genotypes. in this study, stool specimens collected from 12 outbreaks of gastroenteritis in taiwan were screened for viral agents between the 23rd of november 2004 and 9th of march 2005. noroviruses were detected in all outbreaks. we detected six different norovirus geno ...200616463123
human and animal enteric caliciviruses in oysters from different coastal regions of the united diseases are a major cause of morbidity and hospitalization worldwide. enteric caliciviruses are capable of persisting in the environment and in the tissues of shellfish. human noroviruses (hunovs) have been implicated in outbreaks linked to shellfish consumption. the genetic and antigenic relatedness between human and animal enteric caliciviruses suggests that interspecies transmission may occur. to determine the occurrence of human and animal enteric caliciviruses in united states m ...200616517625
genetic analysis of noroviruses associated with fatalities in healthcare facilities.norovirus outbreaks occurred in 236 healthcare facilities for the elderly in japan during the winter of 2004-2005. three norovirus strains associated with three fatal clinical courses were isolated from geographically separate facilities and genetically analyzed along with three strains from non-fatal cases in the same season. all six isolates were classified as the gii-4 genotype. no new variant strains like those observed in europe in 2002 and 2004 were found in fatal cases, and the three outb ...200616521046
changing distribution of norovirus genotypes and genetic analysis of recombinant giib among infants and children with diarrhea in japan.a total of 402 fecal specimens collected during july 2003-june 2004 from infants and children with acute gastroenteritis, encompassing five localities (maizuru, tokyo, sapporo, saga, and osaka) of japan, were tested for the presence of norovirus by rt-pcr. it was found that 58 (14.4%) fecal specimens were positive for norovirus. norovirus infection was detected throughout the year with the highest prevalence in december. norovirus gii was the most predominant genogroup (98.3%; 57 of 58). the gen ...200616721850
fecal viral load and norovirus-associated gastroenteritis.we report the median cdna viral load of norovirus genogroup ii is >100-fold higher than that of genogroup i in the fecal specimens of patients with norovirus-associated gastroenteritis. we speculate that increased cdna viral load accounts for the higher transmissibility of genogroup ii strains through the fecal-oral route.200616965715
a nucleic acid sequence-based amplification assay for real-time detection of norovirus genogroup use molecular beacon based nucleic acid sequence-based amplification (nasba) to develop a rapid, sensitive, specific detection method for norovirus (nv) genogroupii (gii).200616968307
antibody prevalence and titer to norovirus (genogroup ii) correlate with secretor (fut2) but not with abo phenotype or lewis (fut3) genotype.histo-blood group antigens and secretor status have been associated with susceptibility to norovirus infections, which suggests that antibody prevalence and titer might correlate with these phenotypes.200617054072
detection and genetic characterization of norovirus strains circulating among infants and children with acute gastroenteritis in japan during 2004-2005.a total of 752 fecal specimens collected during the period of july 2004 to june 2005 from infants and children with acute gastroenteritis from four different regions (maizuru, tokyo, sapporo, and osaka) of japan were tested for the presence of norovirus by rt-pcr. it was found that 139 (18.5%) fecal specimens were positive for norovirus. norovirus infection was detected almost all year round with the highest prevalence in january. norovirus gii was the most predominant genogroup (98.6%; 137 of 1 ...200617078480
genetic variation in the conservative gene region of norovirus genogroup ii strains in environmental and stool samples.noroviruses (novs) have been one of leading etiological agents for infectious gastroenteritis over the world. gastroenteritis caused by novs is prevalent in winter season, and the contamination of the water environment with novs in the epidemic cold season is frequently reported. in contrast, the number of gastroenteritis patients and novs in the water environment are reduced during the nonepidemic summer season, and the year-round fate of novs has remained to be elucidated. in this study, we co ...200617180998
comparison of methods for detection of norovirus in the absence of culture methods for noroviruses, detection in foods relies on molecular techniques such as reverse transcription-polymerase chain reaction (rt-pcr) on extracted viral rna followed by pcr product confirmation by hybridisation and/or sequencing. however, in order to obtain a successful detection it is of great importance to remove the tissue inhibitors during the viral rna extraction. to select the most efficient extraction procedure of oysters we have compared four protocols. a ...200717182147
evaluation of two commercial enzyme immunoassays for the detection of norovirus in faecal samples from hospitalised children with sporadic acute gastroenteritis.two commercially available enzyme immunoassays (eias), ideia and ridascreen, for norovirus antigen detection were evaluated with 117 faecal samples from hospitalised children with acute gastroenteritis. eighteen of 39 samples positive by rt-pcr were characterised by sequence analysis, and 17 of these were related to norovirus genogroup ii. when compared with rt-pcr, the sensitivity and specificity values were 76.9% and 85.9%, respectively, for the ideia assay, and 59.0% and 73.1%, respectively, ...200717391396
evaluation of immunochromatography tests for detection of rotavirus and norovirus among vietnamese children with acute gastroenteritis and the emergence of a novel norovirus gii.4 variant.a prospective study was conducted to evaluate two immunochromatography (icg) tests for detection of group a rotavirus and norovirus gii, the commercial dipstick 'eiken' rota kit (sa scientific, usa) and the nv ic-1 stick (immuno-probe, japan). polymerase chain reaction (pcr) with specific primer pairs (beg9 and vp7-1', for group a rotavirus; cog2f and g2skr, for norovirus gii) was used as the reference method. the results of icg tests were compared with those of reference method. the sensitivity ...200717496324
cytokine and antibody responses in gnotobiotic pigs after infection with human norovirus genogroup ii.4 (hs66 strain).a human norovirus genogroup ii.4 strain hs66 (hunov-hs66) infects and causes mild diarrhea in gnotobiotic (gn) pigs (s. cheetham, m. souza, t. meulia, s. grimes, m. g. han, and l. j. saif, j. virol. 80:10372-10381, 2006). in this study we evaluated systemic and intestinal humoral and cellular immune responses to hunov-hs66 in orally inoculated pigs. antibodies and type i interferon (ifn-i or ifn-alpha), proinflammatory interleukin-6 (il-6), th1 (il-12 and ifn-gamma), th2 (il-4), and th2/regulato ...200717581999
norovirus gii/4 variants observed in outbreaks of gastroenteritis in miyagi prefecture between november and december of 2006. 200717642546
detection and genetic characterization of norovirus in oysters from china and japan.a total of 225 oysters from china and japan were collected during october 2005 to september 2006 and were then tested for the presence of norovirus by rt-nested pcr. the detection rate of norovirus was different between china and japan, accounting for 14.6% (19 of 130) and 25.3% (24 of 95), respectively. in china, norovirus in oyster was detected continuously from july to february with the highest prevalence in august, october and november (each of 21%, 4 of 19). on the other hand, norovirus in ...200717821944
genetic variation of the norovirus gii-4 genotype associated with a large number of outbreaks in chiba prefecture, japan.between october and december, 2006, high activity of three genetically distinct norovirus gii-4 subtypes was observed in chiba prefecture, japan. one subtype was newly identified in this period and it was detected in 85% of outbreaks.200717851731
molecular and epidemiological trend of norovirus associated gastroenteritis in dhaka city, bangladesh.diarrhea, over the years, has killed millions of people and continues to be a major threat in bangladesh.200717881286
new variant of norovirus gii/4 strains prevalent in yokohama city, october 2006-march 2007. 200717881880
norovirus infections in symptomatic and asymptomatic food handlers in japan.noroviruses are the leading cause of outbreaks of gastroenteritis in the world. at present, norovirus genogroup ii, genotype 4 (gii/4), strains are the most prevalent in many countries. in this study we investigated 55 outbreaks and 35 sporadic cases of norovirus-associated gastroenteritis in food handlers in food-catering settings between 10 november 2005 and 9 december 2006 in japan. stool specimens were collected from both symptomatic and asymptomatic individuals and were examined for norovir ...200717928420
a human norovirus-like particle vaccine adjuvanted with iscom or mlt induces cytokine and antibody responses and protection to the homologous gii.4 human norovirus in a gnotobiotic pig disease model.we inoculated gnotobiotic pigs orally/intranasally with human norovirus gii.4 hs66 strain virus-like particles (vlp) and immunostimulating complexes (iscom) or mutant e. coli lt toxin (mlt, r192g) as mucosal adjuvants, then assessed intestinal and systemic antibody and cytokine responses and homologous protection. both vaccines induced high rates of seroconversion (100%) and coproconversion (75-100%). the vlp+mlt vaccine induced th1/th2 serum cytokines and cytokine secreting cells, whereas the v ...200718022293
phylogenetic analysis of norovirus isolates involved in some canadian gastroenteritis outbreaks in 2004 and 2005.noroviruses are recognized as the most common cause of nonbacterial gastroenteritis worldwide. in this study, we investigated the molecular epidemiology of noroviral isolates in canada from 2004 to 2005 by sequencing the rna polymerase gene and capsid n-terminal/shell (n/s) domain. norovirus genogroups i and ii were thus found to have co-circulated in canada during the studied period, with a higher incidence of genogroup ii (95.7%). the gii-4 or lordsdale subgroup was the predominant genotype, s ...200718026205
[a preliminary study on molecular characteristics of noroviruses detected in beijing].to investigate the molecular characteristics of noroviruses detected in beijing.200718069556
epidemics of gastroenteritis during 2006 were associated with the spread of norovirus gii.4 variants 2006a and 2006b.acute gastroenteritis is commonly associated with norovirus genogroup ii (gii) infection. norovirus gii has 17 classified genotypes (gii.1-gii.17), but only 1 norovirus genotype (gii.4) is associated with global epidemics of gastroenteritis. in 2006, an increase in global norovirus activity was observed.200818177226
norovirus gii.4 strains and outbreaks, australia. 200718214205
evaluation of viral extraction methods on a broad range of ready-to-eat foods with conventional and real-time rt-pcr for norovirus gii detection.noroviruses (nov) are a common cause of foodborne outbreaks. in spite of that, no standard viral detection method is available for food products. therefore, three viral elution-concentration methods and one direct rna isolation method were evaluated on a broad range of ready-to-eat (rte) food products (mixed lettuce, fruit salad, raspberries and two rte dishes) artificially seeded with a diluted stool sample contaminated with nov genogroup ii. these seeding experiments revealed two categories of ...200818258325
multiple norovirus outbreaks among workplace canteen users in finland, july 2006.multiple gastroenteritis outbreaks occurred between 25 and 31 july 2006 in 10 workplace canteens in south-western finland. one vegetable processing plant provided raw vegetables to all the canteens. we conducted cohort studies in the three most visited canteens and environmental investigations in the kitchens and the plant. patients' stools, food, water and environmental samples were tested for enteric bacteria and viruses. of the three canteens, 150/273 respondents (response rate 82%) had gastr ...200918387215
norovirus excretion in an aged-care setting.norovirus genogroup ii excretion during an outbreak of gastroenteritis was investigated in an aged-care facility. viral shedding peaked in the acute stage of illness and continued for an average of 28.7 days. the viral decay rate was 0.76 per day, which corresponds to a viral half-life of 2.5 days.200818417655
food-borne viruses in europe network report: the norovirus gii.4 2006b (for us named minerva-like, for japan kobe034-like, for uk v6) variant now dominant in early seasonal surveillance. 200818445388
norovirus genotype iib associated acute gastroenteritis in india the role of noroviruses in causing gastroenteritis is not well defined.200818467163
histo-blood group antigens and susceptibility to infection with norovirus genogroup ii genotype 4. 200818721065
identification of monomorphic and divergent haplotypes in the 2006-2007 norovirus gii/4 epidemic population by genomewide tracing of evolutionary history.our norovirus (nov) surveillance group reported a >4-fold increase in nov infection in japan during the winter of 2006-2007 compared to the previous winter. because the increase was not linked to changes in the surveillance system, we suspected the emergence of new nov gii/4 epidemic variants. to obtain information on viral changes, we conducted full-length genomic analysis. stool specimens from 55 acute gastroenteritis patients of various ages were collected at 11 sites in japan between may 200 ...200818768979
multiple outbreaks of gastroenteritis due to a single strain of genotype gii/4 norovirus in kobe, japan, 2006: risk factors for norovirus spread in health care settings.a large number of gastroenteritis outbreaks due to a norovirus gii/4 strain and its variants occurred during november and december 2006 in kobe, japan. of the 118 outbreaks, 6 were foodborne and 112 were caused by person-to-person transmission in healthcare settings such as nursing homes and hospitals. the distribution of norovirus outbreaks in healthcare settings was skewed, particularly in the south coastal area. moreover, several outbreaks occurred within 1 km(2) in various areas. outbreaks i ...200818806359
food poisoning outbreak caused by norovirus gii/4 in school lunch, tochigi prefecture, japan. 200818806360
human noroviruses recognize sialyl lewis x neoglycoprotein.the carbohydrate binding characteristics of a norovirus gii.3 (chron1) and a gii.4 (dijon) strain were investigated using virus-like particles (vlps) and saliva samples from 81 individuals genotyped for fut2 (secretor) and fut3 (lewis) and phenotyped for abo and lewis blood groups. the two vlps showed a typical secretor-gene-dependent binding and bound significantly stronger to saliva from a, b, and ab than from o individuals (p < 0.0001 and p < 0.001) but did not bind to any samples from secret ...200919054801
identification and characterization of a native epitope common to norovirus strains gii/4, gii/7 and gii/8.norovirus is an important cause of acute non-bacterial gastroenteritis in humans. the norovirus genus is comprised of at least five genogroups based on sequence differences. the norovirus genogroup ii (gii/4) strain is recognized as the predominant genotype worldwide. we expressed a 60 kda full-length recombinant capsid protein of norovirus gii/4 in escherichia coli and generated three monoclonal antibodies (mabs) against it. western blotting indicated that all three mabs had reactivity against ...200919121346
a foodborne outbreak due to norovirus in austria, 2007.a foodborne norovirus outbreak occurred after a pre-christmas celebration among a group of local foresters in austria in december 2007. a total of 66 persons, 60 participants of the christmas party and 6 kitchen staff members of the restaurant where the party took place, were identified as the at-risk cohort. questioning of this cohort was performed by self-report questionnaires or telephone interviews (response rate of 95%). the outbreak attack rate was 33.3% (21 of 63 persons), including two o ...200919205486
a novel bocavirus associated with acute gastroenteritis in australian children.acute gastroenteritis (age) is a common illness affecting all age groups worldwide, causing an estimated three million deaths annually. viruses such as rotavirus, adenovirus, and caliciviruses are a major cause of age, but in many patients a causal agent cannot be found despite extensive diagnostic testing. proposing that novel viruses are the reason for this diagnostic gap, we used molecular screening to investigate a cluster of undiagnosed cases that were part of a larger case control study in ...200919381259
development of monoclonal antibody-coated immunomagnetic beads for separation and detection of norovirus (genogroup ii) in faecal extract samples.the aim of this study is to develop an rt-pcr assay combined with immunomagnetic beads (ims/rt-pcr) coating monoclonal antibody (mab) for separation and detection of norovirus (genogroup ii) in faecal samples. we furthermore compare its detection limits with ims/rt-pcr using polyclonal antibody (pab) and the trizol extraction method followed by rt-pcr (trizol-rt-pcr).200919453950
identification of a novel codon in the norovirus gii.4 polymerase region which acts as a marker of major gii.4 norovirus epidemics.noroviruses are considered the most common cause of outbreaks of non-bacterial gastroenteritis in humans and the gii.4 genotype the most common norovirus genotype. previous studies have shown that two adjacent codons acted as markers of the severity of gii.4 norovirus outbreak epidemics. in this study, a further such codon was identified at nucleotide position 4670-4672 relative to the norovirus strain lordsdale virus (genbank accession no. x86557). taken together, the data indicate these epidem ...200919460334
a new variant of norovirus gii.4/2007 and inter-genotype recombinant strains of nvgii causing acute watery diarrhoea among children in kolkata, india.noroviruses (novs) are one of the major causal agents of acute gastroenteritis among different age groups. some of the recent studies reveal that nov genome is highly prone to mutation and recombination which often leads to emergence of new strains.200919464942
prevalence and genotypes of human noroviruses in tropical urban surface waters and clinical samples in singapore.the prevalence and genotypes of norovirus genogroup i (gi) and gii in tropical urban catchment waters and an estuarine bay were studied. a comparative analysis was performed with environmental isolates of noroviruses and concurrently identified clinical isolates in singapore during gastroenteritis outbreaks between august 2006 to january 2007. noroviruses in environmental water samples were concentrated by using ultrafiltration techniques and then analyzed by reverse transcription-seminested pcr ...200919525276
nitric oxide production in acute gastroenteritis in indian children.this study compared nitric oxide (no) levels in 110 children with, and 110 children without, infectious gastroenteritis. post-infection intestinal function was assessed in a subset. at least one pathogen was identified in 47.2% of cases. the most common diarrhoeal pathogens were rotavirus (22.7%) and norovirus genogroup ii (11.8%). the levels of no measured by median urinary nitrite:creatinine ratio were significantly higher in children with diarrhoea [23.6; interquartile range (iqr) 12.3-46.7] ...200919552932
norovirus illness is a global problem: emergence and spread of norovirus gii.4 variants, 2001-2007.noroviruses (novs) are the most common cause of viral gastroenteritis. their high incidence and importance in health care facilities result in a great impact on public health. studies from around the world describing increasing prevalence have been difficult to compare because of differing nomenclatures for variants of the dominant genotype, gii.4. we studied the global patterns of gii.4 epidemiology in relation to its genetic diversity.200919627248
symptomatic and asymptomatic rotavirus and norovirus infections during infancy in a chilean birth cohort.rotavirus and more recently norovirus have been recognized as 2 of the most common causes of acute diarrhea in children. comparative analysis of these infections in a birth cohort has not been performed and can provide relevant insight on clinical and viral behaviors.200919672213
concentration method for the detection of enteric viruses from large volumes of foods.enteric viruses are the major cause of outbreaks of foodborne viral disease worldwide, and vegetables and fruits are considered significant vectors of virus transmission. in this study, we compared viral elution concentration methods in strawberry and lettuce and tested the secondary concentration step for concentrating viruses from large volumes of lettuce samples. among the tested procedures, the combination of a 0.05 m glycine plus 100 mm tris elution buffer (ph 9.5) and a polyethylene glycol ...200919777907
application of a modified loop-mediated isothermal amplification kit for detecting norovirus genogroups i and ii.norovirus is a major etiologic agent in worldwide outbreaks of gastroenteritis associated with food as well as person-to-person transmission. the ubiquitous nature of norovirus necessitates simple and rapid detection methods with high accuracy and sensitivity. to this end, several investigators have evaluated the usefulness of commercial reverse-transcription loop-mediated isothermal amplification (rt-lamp) kits for detecting norovirus genogroups i (gi) and ii (gii). in previous studies, the con ...200919856470
a foodborne outbreak of norovirus gastroenteritis associated with a christmas dinner in porto, portugal, december outbreak of acute norovirus gastroenteritis was detected and epidemiologically linked to a christmas dinner reunion of 22 recent graduate students in a restaurant in porto, portugal, in december 2008. a retrospective cohort study was carried out using online standardised questionnaires. sixteen primary and three secondary cases were identified and the risk ratios with 95% confidence intervals for each food item were calculated. the response rate to the online questionnaires was 96%. the outbr ...200919883537
non-rotavirus infection causing apnea in a neonate.apnea in a premature infant is not always due to immaturity and caffeine is not always the answer. we report a case of apnea in a preterm infant who presented at two weeks of life with increase in frequency of apnea that did not respond to caffeine. family history was significant for diarrhea in a sibling. stool pcr was positive for norovirus genogroup ii. enteric isolation was instituted and the apnea resolved spontaneously with conservative management. re-emergence of apnea or persistent apnea ...200919907939
effects of technological processes on the tenacity and inactivation of norovirus genogroup ii in experimentally contaminated foods.contaminated food is a significant vehicle for human norovirus transmission. the present study determined the effect of physicochemical treatments on the tenacity of infective human norovirus genogroup ii in selected foods. artificially contaminated produce was subjected to a number of processes used by the food industry for preservation and by the consumer for storage and preparation. virus recovery was carried out by using ultrafiltration and was monitored by using bacteriophage ms2 as an inte ...201019933338
a foodborne norovirus outbreak at a hospital and an attached long-term care facility.we investigated a foodborne norovirus outbreak in a hospital and an attached long-term care facility (ltcf). an at-risk group of 698 people was identified, which included staff, hospital patients, ltcf residents, and adult daycare users who shared consumption of food prepared in a central kitchen. three different diets were prepared in three separate sections: a standard diet, a special diet, and a diet for residents at the ltcf. during the first 3 days of the outbreak, 47 (16%) of 285 staff mem ...200919934537
molecular characterization of three novel intergenotype norovirus gii recombinant strains from western india.the phenomenon of recombination has been widely described among noroviruses (novs) in the past few years. in a nov surveillance study conducted in western india, 3 novel and 3 known combinations of rna-dependent rna polymerase (rdrp) and capsid genes were identified in genogroup (g) ii nov strains. the present study pertains to the characterization of three novel intergenotype nov gii recombinant strains. rt-pcrs were carried out for the amplification of nearly complete rdrp and complete capsid ...201019941918
real-time molecular beacon nasba for rapid and sensitive detection of norovirus gii in clinical improve the sensitivity and efficiency of the real-time nucleic acid sequence based amplification (nasba) assay targeting the open reading frame 1-2 (orf1-orf2) junction of the norovirus (nov) genome, a selection of clinical samples were analyzed. the assay results were compared with those of taqman and conventional reverse transcription pcr (rt-pcr) and a commercial enzyme-linked immunoassay (elisa) for the specific detection of gii nov in 96 fecal samples. based on end-point dilution, the t ...200920029529
spontaneous bowel perforation due to norovirus: a case report.norovirus is the leading cause of epidemic gastroenteritis worldwide but the disease is usually self-limiting and generally only causes serious health problems in the young, elderly and immunocompromised. the authors report a case of bowel perforation in an elderly caucasian lady with confirmed infection with norovirus genogroup ii and no other presumptive cause. to the authors' knowledge this is the first such case of bowel perforation due to norovirus. viral gastroenteritis should be considere ...200920062678
first detection of porcine norovirus gii.18 in latin america.human (hu) noroviruses (novs) circulate worldwide infecting people of all ages in developing and developed countries. animal novs present some antigenic and genetic relationship to hunovs, although their zoonotic potential has not been established yet. among animal novs, porcine (po) novs are the most genetically related to hunovs. ponovs have only been detected in healthy finisher pigs in a few developed countries. information about them lacks in developing countries. in this study 96 fecal sam ...201020080272
human caliciviruses detected in mexican children admitted to hospital during 1998-2000, with severe acute gastroenteritis not due to other enteropathogens.few studies exist regarding the frequency of human caliciviruses as single etiologic agents in sporadic cases, or in outbreaks occurring in children hospitalized for acute gastroenteritis. in this study, a total of 1,129 children of <5 years of age and hospitalized due to acute diarrhea were enrolled from three main hospitals in mexico city during a period of 3 years (march 1998 to december 2000). after analyzing all fecal samples for several enteropathogens, 396 stools that remained negative we ...201020166189
evaluation of adenovirus and e. coli as indicators for human enteric viruses presence in mussels produced in la spezia gulf (italy).the purpose of this work was to verify whether e. coli is a good indicator of viral contamination in mussels and adenovirus could represent a better alternative as indicator organism of viral presence to guarantee consumer health protection.201020184672
simultaneous separation and detection of hepatitis a virus and norovirus in produce.two sample preparation methods based on electrostatic binding were tested to simultaneously separate different viral particles from different food surfaces (lettuce, strawberry, raspberries and green onions). both methods were evaluated using a multiplex real-time pcr assay designed for detection of hepatitis a virus and norovirus gi and gii. single and multiplex detection limits were determined as 10(1) viral particles for hav and norovirus gii, and 10(2) viral particles for norovirus gi using ...201020223543
genetic analysis of norovirus gii.4 variants circulating in korea in 2008.noroviruses are the enteric pathogens most commonly responsible for infectious gastroenteritis and outbreaks of foodborne illness. the gii.4 norovirus, in particular, is responsible for the majority of epidemics. here, we present data on the distribution of norovirus genotypes in chungnam, korea, in 2008, measure genetic variation among gii.4 strains, and compare korean gii.4 variants with reference strains based on the 237-bp junction of orf1 and orf2. we detected 139 different strains, which f ...201020224892
environmental surveillance and molecular characterization of human enteric viruses in tropical urban study the prevalence and genotypes of waterborne pathogenic viruses in urban wastewaters in the tropical region.201020233263
norovirus gii-4 2006b variant circulating in patients with acute gastroenteritis in thailand during a 2006-2007 study.noroviruses (novs) are recognized as a significant cause of acute gastroenteritis in children and adults. a 14-month study, from january 2006 to february 2007, was undertaken in a hospital in thailand to determine the prevalence and genetic characterization of novs in patients of all ages with acute gastroenteritis. based on reverse transcription-nested polymerase chain reaction (rt-nested pcr), novs were detected in 122 of 273 (44.7%) collected stool samples. of the 122 nov-positive samples, 28 ...201020336729
characterization of a cross-reactive monoclonal antibody against norovirus genogroups i, ii, iii and v.noroviruses cause the majority of epidemic outbreaks of acute viral gastroenteritis worldwide. in a previous study of monoclonal antibodies against norovirus gii/4 strain, we identified a continuous epitope (55)wirnnf(60) that was recognized by mab n2c3. subsequent studies found that this mab could recognize several different strains of noroviruses, not just gii/4. in the present study, we used homology modeling to confirm that the epitope of n2c3 was exposed on the surface of gii/4 capsid prote ...201020417671
isolated norovirus gii.7 strain within an extended gii.4 outbreak.noroviruses are a major cause of viral gastroenteritis and have been detected with increasing prevalence in recent years. currently, two main genogroups gi and gii with an increasing number of subtypes are differentiated. because of a high genetic variability new variants emerge constantly allowing epidemiological tracing of viruses from year to year and location to location. a 282 bp sequence at the 5'end of the capsid gene was analyzed in isolates originating from the university hospital, tech ...201020419822
genetic characterization of norovirus gii.4 2006b variants from jeju island, south korea.ninety-seven fecal specimens collected from children with acute gastroenteritis between 2007 and 2008 that were found to be negative for group a rotavirus in prescreening by elisa with vp6-specific antibody were re-screened for viruses by reverse transcription (rt)-pcr. forty (41.2%) samples were found to be positive for virus by rt-pcr; of these, norovirus (32.5%, n = 13) and rotavirus (32.5%, n = 13) were the most common, followed by astrovirus (5.0%, n = 2) and enterovirus (2.5%, n = 1). co-i ...201020419823
phylodynamic reconstruction reveals norovirus gii.4 epidemic expansions and their molecular determinants.noroviruses are the most common cause of viral gastroenteritis. an increase in the number of globally reported norovirus outbreaks was seen the past decade, especially for outbreaks caused by successive genogroup ii genotype 4 (gii.4) variants. whether this observed increase was due to an upswing in the number of infections, or to a surveillance artifact caused by heightened awareness and concomitant improved reporting, remained unclear. therefore, we set out to study the population structure an ...201020463813
divergent evolution of norovirus gii/4 by genome recombination from may 2006 to february 2009 in japan.norovirus gii/4 is a leading cause of acute viral gastroenteritis in humans. we examined here how the gii/4 virus evolves to generate and sustain new epidemics in humans, using 199 near-full-length gii/4 genome sequences and 11 genome segment clones from human stool specimens collected at 19 sites in japan between may 2006 and february 2009. phylogenetic studies demonstrated outbreaks of 7 monophyletic gii/4 subtypes, among which a single subtype, termed 2006b, had continually predominated. phyl ...201020534859
norovirus encephalopathy in a previously healthy child.norovirus causes acute gastroenteritis in all age groups. afebrile convulsion is an occasional neurologic complication in norovirus infection, but encephalitis is rare. we report the case of a previously healthy 15-month-old girl with norovirus encephalopathy who had a poor neurologic outcome. norovirus (genogroup ii) was detected in plasma and stool by real-time reverse transcription polymerase chain reaction, but the cerebrospinal fluid showed negative result for genome. elevated concentration ...201020555291
chemical and microbiological parameters as possible indicators for human enteric viruses in surface water.there are still conflicting results on the suitability of chemical and microbiological parameters as indicators for the viral contamination of surface waters. in this study, conducted over 20 months, the abundance of human adenovirus, human polyomavirus, enterovirus, group a rotavirus and norovirus was determined in ruhr and rhine rivers, germany. additionally, prevalence of different possible indicators such as somatic coliphages, e. coli, intestinal enterococci, and total coliforms was also co ...201020556879
asymptomatic norovirus infections in nicaraguan children and its association with viral properties and histo-blood group has been previously reported that histo-blood group antigens (hbgas) and particularly secretor status provides protection against symptomatic norovirus infection, but it remains unclear to what extent this includes asymptomatic infections in children.201020657344
influence of novel norovirus gii.4 variants on gastroenteritis outbreak dynamics in alberta and the northern territories, canada between 2000 and 2008.norovirus gii.4 is the predominant genotype circulating worldwide over the last decade causing 80% of all norovirus outbreaks with new gii.4 variants reported in parallel with periodic epidemic waves of norovirus outbreaks. the circulating new gii.4 variants and the epidemiology of norovirus outbreaks in alberta, canada have not been described. our hypothesis is that the periodic epidemic norovirus outbreak activity in alberta was driven by new gii.4 variants evolving by genetic drift.201020661286
a comparison of methods for purification and concentration of norovirus gii-4 capsid virus-like particles.noroviruses (novs) are one of the leading causes of acute gastroenteritis worldwide. nov gii-4 vp1 protein was expressed in a recombinant baculovirus system using sf9 insect cells. several methods for purification and concentration of virus-like particles (vlps) were evaluated. electron microscopy (em) and histo-blood group antigen (hbga) binding assays showed that repeated sucrose gradient purification followed by ultrafiltration resulted in intact vlps with excellent binding to h type 3 antige ...201020721592
norovirus-binding proteins recovered from activated sludge micro-organisms with an affinity to a noroviral capsid peptide.transmission routes of noroviruses, leading aetiological agents of acute gastroenteritis, are rarely verified when outbreaks occur. because the destination of norovirus particles being firmly captured by micro-organisms could be totally different from that of those particles moving freely, micro-organisms with natural affinity ligands such as virus-binding proteins would affect the fate of viruses in environment, if such microbial affinity ligands exist. the aim of this study is to identify noro ...201020735509
diagnosis of viral gastroenteritis by simultaneous detection of adenovirus group f, astrovirus, rotavirus group a, norovirus genogroups i and ii, and sapovirus in two internally controlled multiplex real-time pcr assays.norovirus, rotavirus group a, astrovirus, sapovirus and adenovirus serotypes 40 and 41, are common causes of gastroenteritis. conventional diagnosis of these causative agents is based on antigen detection and electron microscopy.201020829103
quantitative real-time pcr of enteric viruses in influent and effluent samples from wastewater treatment plants in italy.the prevalence of enteric viruses in wastewater, the efficacy of wastewater treatments in eliminating such viruses, and potential health risks from their release into the environment or by recycling of treated wastewaters, are very important issues in environmental microbiology. in this study we performed a quantitative taqman real-time pcr (polymerase chain reaction) analysis of enteric viruses on samples of influents and effluents from 5 wastewater treatment plants in and around rome. three ep ...201020847459
[survival strategies of human norovirus].human norovirus is a mutatable non-enveloped rna virus capable of causing acute gastroenteritis in humans. thus far, no experimental systems can propagate this virus in large amounts. recent progresses in viral genomics and bioinformatics have led to a better understanding of molecular evolution of this virus in human populations. in addition, progresses in studies of the related noroviruses, those are replicable in laboratory systems, have led to a rapid accumulation of information on structura ...201020848862
chronological observation of shell domain of norovirus gii.4 major structural protein vp1. 201020859010
emerging norovirus gii.4 2008 variant detected in hospitalised paediatric patients in south africa.noroviruses (novs) are important enteric pathogens that cause gastroenteritis worldwide. the first documented nov outbreaks in south africa (sa) were described in 1993. the current nov prevalence and circulating genotypes are unknown. sa lacks nov outbreak reporting systems and therefore the number and impact of nov infections is underestimated.201020869912
norovirus gii.4 variant 2006b caused epidemics of acute gastroenteritis in australia during 2007 and 2008.over the last decade, four epidemics of norovirus-associated gastroenteritis have been reported in australia. these epidemics were characterized by numerous outbreaks in institutional settings such as hospitals and nursing homes, as well as increases in requests for nov testing in diagnostic centers. during 2007 and 2008, widespread outbreaks of acute gastroenteritis were once again seen across australia, peaking during the winter months.201020888289
norovirus gii.4 strain antigenic variation.noroviruses are the principal cause of epidemic gastroenteritis worldwide. multiple reports have concluded that the major capsid proteins of gii.4 strains, which cause 80% of norovirus infections worldwide, are evolving rapidly, resulting in new epidemic strains. surrogate neutralization assays using sera from outbreaks and from immunized mice suggest that, as with influenza virus, antigenic variation maintains gii.4 persistence in the face of human population herd immunity. to test this hypothe ...201020980508
emergence of norovirus gii-4/2008 variant and recombinant strains in seoul, korea.recently, the emergence of a new nov gii-4 variant strain every 2 or 3 years has been reported. one hundred seventeen nov gii strains were detected by rt-pcr in children with age between august 2008 and february 2010. in phylogenetic analyses, gii-4 and gii-3 were the most frequently detected strains. the detection rate of the 2008 variant was similar to that of the 2006b variant in the winter seasons of 2009 and 2010. this study shows a changing pattern of a predominant gii-4/2006b variant to t ...201021053029
emergence of noroviruses homologous to strains reported from djibouti (horn of africa), brazil, italy, japan and usa among children in kolkata, india.a total of 625 faecal specimens of diarrheic cases (n-313) and non diarrheic controls (n-312), were screened by rt-pcr to detect noroviruses in children aged below 5 years in kolkata, india.201021061839
improved detection and quantitation of norovirus from water.norovirus is associated commonly with human sewage and is responsible for numerous cases of waterborne and foodborne gastroenteritis every year. assays using reverse transcription-quantitative polymerase chain reaction (rt-qpcr) have been developed for norovirus, however, accurate detection and quantitation remain problematic owing to a lack of suitable positive controls. to improve enumeration of norovirus genomes from water, a synthetic norovirus genogroup ii quantitation standard and competit ...201021185870
the use of bovine serum albumin to improve the rt-qpcr detection of foodborne viruses rinsed from vegetable demonstrate that produce rinsates used for rt-qpcr detection of foodborne viruses may cause significant pcr inhibition and propose a means to reduce its impact on sensitivity.201121219370
prevalence of norovirus gii-4 antibodies in finnish children.noroviruses (novs) are the second most common cause of viral gastroenteritis after rotavirus in children. nov genotype gii-4 has emerged as the major type not only in outbreaks of nov gastroenteritis but also endemic gastroenteritis among infants and young children worldwide. using baculovirus-insect cell system virus-like particles (vlps) of nov genotype gii-4 and an uncommon genotype gii-12 were produced. these vlps were used in enzyme-linked immunosorbent assays (elisa) for detection of nov-s ...201121264875
a single-tube multiplex pcr for rapid detection in feces of 10 viruses causing diarrhea.a novel multiplex polymerase chain reaction assay was developed to identify 10 viruses in a single tube. the assay was targeted to detect group a and c rotaviruses, adenovirus, norovirus gi, norovirus gii, sapovirus, astrovirus, aichi virus, parechovirus, and enterovirus. a total of 235 stool samples were collected from infants and children with acute gastroenteritis in kyoto, japan, from 2008 to 2009, then tested by this novel multiplex pcr and compared with a multiplex pcr described previously ...201121349292
norovirus gii-4 causes a more severe gastroenteritis than other noroviruses in young children.norovirus (nov) gii-4 has emerged as the predominant nov genotype in outbreaks of gastroenteritis worldwide. we determined clinical features of nov gii-4 associated acute gastroenteritis (age) in comparison with age associated with other nov types in infants during seasons 2001 and 2002. during the prospective follow-up period, 128 primary infections of age due to nov were identified in 405 infants; of these, gii-4 was found in 40 cases (31%). nov gii-4 was associated with longer duration of dia ...201121415019
removal of human enteric viruses by a full-scale membrane bioreactor during municipal wastewater the us, human enteric viruses are the main etiologic agents of childhood gastroenteritis, resulting in several hospitalizations and deaths each year. these viruses have been linked to several waterborne diseases, such as acute gastroenteritis, conjunctivitis and respiratory illness. the removal of human enterovirus (ev) and norovirus genogroup ii (nov ggii) was studied in a full-scale membrane bioreactor (mbr) wastewater treatment plant (wwtp) and compared with the removal of human adenovirus ...201121453953
[study on concentration of nuorovirus genegroup ii from environmental water].a new viral sampling concentration device was designed which was equipped with a new cationic filter membrane-nanoceram suitable for field sampling. norovirus genegroup ii was detected from environmental water with the aid of this device. the effects on virus recovery of prefiltration, various second-concentration methods, and different eluants were investigated through pre-experiment. the concentration optimized process, and the optimal concentration process were then determined. the results sh ...201121462507
Displaying items 1 - 100 of 352