Publications

nucleotide sequence analysis and development of consensus primers of rt-pcr for detection of norwalk-like viruses prevailing in japan.	a total of 177 different nucleotide sequences of the rna polymerase region of norwalk-like viruses (nlvs) genomes, collected via a nation-wide survey project in japan between 1989 and 1998, were examined by reverse transcription-polymerase chain reaction (rt-pcr) employing various primer pairs. the nucleotide sequences of different strains showed great diversity, with a range of 57 to 100% identities among strains. the strains could be classified into five clusters: norwalk (nv), snow mountain a ...	2001	11468745
rapid and efficient extraction method for reverse transcription-pcr detection of hepatitis a and norwalk-like viruses in shellfish.	as part of an effort to develop a broadly applicable test for norwalk-like viruses and hepatitis a virus (hav) in shellfish, a rapid extraction method that is suitable for use with one-step reverse transcription (rt)-pcr-based detection methods was developed. the method involves virus extraction using a ph 9.5 glycine buffer, polyethylene glycol (peg) precipitation, tri-reagent, and purification of viral poly(a) rna by using magnetic poly(dt) beads. this glycine-peg-tri-reagent-poly(dt) method c ...	2001	11526018
characterization of "norwalk-like viruses" and astroviruses by liquid hybridization assay.	"norwalk-like viruses" (nlvs) and human astroviruses are causative agents of gastroenteritis in all age-groups. the typing of these agents is generally done by nucleotide sequencing, blot hybridization, or enzyme immunoassay. these techniques are expensive, time-consuming, and sometimes require scarce reagents, which limits the typing of nlvs and astroviruses to a few reference laboratories. this report describes a liquid hybridization assay that uses broadly reactive probes whose sequences are ...	2001	11164493
the molecular biology of human caliciviruses.	within the last decade molecular analyses of the genome of norwalk-like viruses (nlvs) have confirmed that this important group of infectious agents belongs to the caliciviridae family. nlvs have a positive-sense, single-stranded rna genome of approximately 7700 nucleotides excluding the polyadenylated tail. the genome encodes three open reading frames: orf 1 is the largest (approximately 1700 amino acids) and is expressed as a polyprotein precursor that is cleaved by the viral 3c-like protease; ...	2001	11444026
multiple outbreaks of norwalk-like virus gastro-enteritis associated with a mediterranean-style restaurant.	the role of diverse infectious agents, particularly norwalk-like viruses (nlv), in three successive gastro-enteritis outbreaks in one setting (a restaurant) was evaluated. methods included standard bacteriological tests, specific tests for escherichia coli, tests for verocytotoxins, electron microscopy (em) for viruses and reverse transcription-pcr (rt-pcr) methodology for nlv. no pathogenic bacteria were detected. verocytotoxin genes, although detected by pcr in the first outbreak, could not be ...	2001	11211221
outbreak of norwalk virus in a caribbean island resort: application of molecular diagnostics to ascertain the vehicle of infection.	in 1998, an outbreak of gastroenteritis affected at least 448 persons including 122 staff at a resort hotel in bermuda. a survey among staff indicated that gastroenteritis was associated with eating or drinking at the hotel (or = 60, 95% ci = 2.4-15.1). multiple specimens of drinking water had elevated faecal coliform levels and escherichia coli present, suggestive of faecal contamination. stools from 18 of the 19 persons with gastroenteritis that were tested were positive for genogroup-ii norwa ...	2001	11467799
simultaneous isolation of verotoxin-producing strains of escherichia coli o128:h2 and viruses in gastroenteritis outbreaks.	three outbreaks of gastroenteritis from which the verotoxin producing escherichia coli serotype o128:h2 was isolated are reported. in addition norwalk-like viruses were detected in patients from two of the outbreaks and astrovirus in the third outbreak. while it cannot be specifically determined which of these agents played the major role in these outbreaks, the findings suggest that the viral agents need to be considered in investigations of gastroenteritis outbreaks, regardless of whether bact ...	2001	11247046
development of a reverse transcription-pcr-dna enzyme immunoassay for detection of "norwalk-like" viruses and hepatitis a virus in stool and shellfish.	outbreaks of food- and waterborne gastroenteritis are being increasingly reported throughout the world. the analysis of environmental samples by newer diagnostic techniques such as reverse transcription-pcr (rt-pcr) amplification of nucleic acid has begun to identify human enteric viruses (predominantly "norwalk-like" viruses [nlvs]) as the cause of many of these outbreaks. to streamline nlv detection from environmental samples such as shellfish, we have developed an rt-pcr-oligoprobe amplificat ...	2001	11157239
molecular detection of human calicivirus in young children hospitalized with acute gastroenteritis in melbourne, australia, during 1999.	reverse transcription-pcr and sequence analysis identified calciviruses in 32 of 60 stool specimens (negative for other enteric pathogens) obtained from children admitted to our hospital with acute gastroenteritis. the overall annual incidence rate for calcivirus was 9% (32 of 354 children). molecular analysis identified 30 "norwalk-like virus" genogroup ii (predominantly lordsdale cluster) and 2 "sapporo-like virus" strains.	2001	11427606
[studies of acute gastroenteritis among infant and young children in a pediatric clinic].	from october 1998 to april 1999, 72 stool specimens from patients of acute gastroenteritis were collected in a pediatric clinic in urawa city, japan and were examined for the detection of srsv by electron microscopy and reverse transcription-polymerase chain reaction (rt-pcr). forty-eight (67%) out of 72 were srsv positives by both tests. in this season, a prevalence of srsv peaked in december 1998. among reported clinical symptoms, vomiting was reported more frequently than the other symptoms, ...	2001	11357324
norwalk-like virus outbreaks at two summer camps--wisconsin, june 2001.	on june 27 and 28, 2001, the wisconsin division of public health was notified by two local health departments of outbreaks of gastroenteritis at two summer recreational camps (camps a and b) in northern wisconsin. this report summarizes the investigation of these outbreaks, which documents person-to-person transmission of "norwalk-like virus" (nlv) and underscores the importance of cleaning environmental surfaces and the availability and use of hand-washing facilities at recreational camps.	2001	11787574
structural studies on gastroenteritis viruses.	there are many recent advances in our understanding of the structure-function relationships in rotavirus, a major pathogen of infantile gastroenteritis, and norwalk virus, a causative agent of epidemic gastroenteritis in humans. rotavirus is a large (1000 a) and complex icosahedral assembly formed by three concentric capsid layers that enclose the viral genome of 11 dsrna segments. because of its medical relevance, intriguing structural complexity, and several unique strategies in the morphogene ...	2001	11444031
high level excretion of norwalk-like virus following resolution of clinical illness.	we report the case of an elderly woman excreting high levels (about 5 x 10(5) virions per gram of faeces) of norwalk-like virus (nlv) in the absence of any clinical symptoms of gastroenteritis. analysis by reverse transcription, polymerase chain reaction and dna sequencing was carried out on a 342-nucleotide region of open reading frame 1. this indicated that the nlv belonged to genogroup 2 and was more closely related to the camberwell subgroup, the most common circulating in southeast australi ...	2001	11280609
molecular epidemiology of 'norwalk-like viruses' associated with gastroenteritis outbreaks in new zealand.	outbreaks of gastroenteritis are a major public health problem in new zealand. the introduction of molecular detection methods has now shown that the 'norwalk-like viruses' (nlvs) are the major cause of food and waterborne nonbacterial gastroenteritis. reverse transcription and polymerase chain reaction (rt-pcr) were used to determine the presence of nlvs in faecal specimens from 83 nonbacterial gastroenteritis outbreaks occurring in new zealand between august 1995 and july 1999. further charact ...	2001	11285570
evaluation of the japanese school health surveillance system for influenza.	in order to evaluate the japanese nationwide school absenteeism surveillance system for pediatric influenza in comparison with the national sentinel surveillance for influenza, we used surveillance guidelines (centers for disease control and prevention, 1998) to determine the efficacy of the school health surveillance system (shss). data regarding school absenteeism (age 4-15 years old) was compared with data regarding influenza-like illness (ili) per sentinel sites during the second to the 11th ...	2001	11326126
clinical spectrum and transmission characteristics of infection with norwalk-like virus: findings from a large community outbreak in sweden.	a large foodborne outbreak caused by norwalk-like virus (nlv) among children and staff at 30 day care centers provided an opportunity to study symptomatology and attack rates among patients in different age groups, as well as secondary transmission rates in centers and households. a retrospective cohort study of 775 subjects from 13 randomly chosen centers was performed. diarrhea was more common in adults than in children (p=.001), whereas the reverse was noted with regard to vomiting (p=.003). ...	2001	11477530
raw oyster consumption and outbreaks of viral gastroenteritis in new zealand: evidence for risk to the public's health.	to investigate the relationship between consumption of raw pacific half shell oysters and outbreaks of norwalk-like virus (nlv) gastroenteritis in auckland in the last third of 1999.	2001	11494991
diffusion of macromolecules and virus-like particles in human cervical mucus.	to determine whether or not large macromolecules and viruses can diffuse through mucus, we observed the motion of proteins, microspheres, and viruses in fresh samples of human cervical mucus using fluorescent recovery after photobleaching and multiple image photography. two capsid virus-like particles, human papilloma virus (55 nm, approximately 20,000 kda) and norwalk virus (38 nm, approximately 10,000 kda), as well as most of the globular proteins tested (15-650 kda) diffused as rapidly in muc ...	2001	11566767
from the centers for disease control and prevention. norwalk-like virus outbreaks at two summer camps--wisconsin, june 2001.		2001	11575312
outbreaks of acute gastroenteritis associated with norwalk-like viruses in campus settings.	norwalk-like viruses (nlvs) are transmitted by fecally contaminated food, water, fomites, and person-to-person contact. they are a leading cause of acute gastroenteritis epidemics in industrialized countries. nlv outbreaks are characterized by a 12- to 48-hour incubation period; nausea, vomiting, and diarrhea for 24 to 72 hours; and high secondary attack rates. nlv infections spread rapidly on college and university campuses because of close living quarters, shared bathrooms and common rooms, ma ...	2001	11590984
enteric virus contamination of foods through industrial practices: a primer on intervention strategies.	hepatitis a and e viruses, rotaviruses, norwalk-like caliciviruses, and astroviruses are among the enteric viruses known to cause food- and waterborne illness. these viruses are spread by the fecal-oral route and are a major cause of morbidity and mortality worldwide. foods may be contaminated at any time pre- or post-harvest; however, many outbreaks are associated with foods handled by infected restaurant workers. produce may be contaminated by improper irrigation or fertilization practices, by ...	2001	11641770
prevalence of norwalk viruses in southern and northern parts of hiroshima prefecture, japan in 2000/2001 season.		2001	11684786
multistate outbreak of norwalk-like virus gastroenteritis associated with a common caterer.	in february 2000, an outbreak of gastroenteritis occurred among employees of a car dealership in new york. the same meal was also supplied to 52 dealerships nationwide, and 13 states reported illness at dealerships where the banquet was served. a retrospective cohort study was conducted to identify risk factors associated with the illness. stool samples were collected to detect norwalk-like virus, and sera were drawn and tested for immunoglobulin a antibodies to the outbreak strain. by univariat ...	2001	11724717
clinical severity of norwalk virus and sapporo virus gastroenteritis in children in hokkaido, japan.	to clarify the clinical significance and etiologic impact of norwalk virus (nv) and sapporo virus (sv) in viral gastroenteritis in japanese children.	2001	11734762
diagnosis of noncultivatable gastroenteritis viruses, the human caliciviruses.	gastroenteritis is one of the most common illnesses of humans, and many different viruses have been causally associated with this disease. of those enteric viruses that have been established as etiologic agents of gastroenteritis, only the human caliciviruses cannot be cultivated in vitro. the cloning of norwalk virus and subsequently of other human caliciviruses has led to the development of several new diagnostic assays. antigen detection enzyme immunoassays (eias) using polyclonal hyperimmune ...	2001	11148001
sensitive detection and differentiation of sapporo virus, a member of the family caliciviridae, by standard and booster nested polymerase chain reaction.	norwalk virus and sapporo virus (sv) were approved as type species of the genus norwalk-like viruses and the genus sapporo-like viruses, respectively, in the family caliciviridae. nested polymerase chain reaction (pcr), using newly designed primers in the rna-dependent rna polymerase region, was developed to detect and differentiate viruses in the three genetic groups of sv based on the relative size of the pcr products obtained. in addition, a booster nested pcr that performs nested pcr in a si ...	2001	11536253
recombinant norwalk virus-like particles administered intranasally to mice induce systemic and mucosal (fecal and vaginal) immune responses.	recombinant norwalk virus-like particles (rnv vlps) were administered to balb/c mice by the intranasal (i.n.) route to evaluate the induction of mucosal antibody responses. the results were compared to systemic and mucosal responses observed in new and previous studies (j. m. ball, m. e. hardy, r. l. atmar, m. e. connor, and m. k. estes, j. virol. 72:1345-1353, 1998) after oral administration of rnv vlps. immunizations were given in the presence or absence of a mucosal adjuvant, mutant escherich ...	2001	11559804
characterization of norwalk virus gi specific monoclonal antibodies generated against escherichia coli expressed capsid protein and the reactivity of two broadly reactive monoclonal antibodies generated against gii capsid towards gi recombinant fragments.	norwalk virus causes outbreaks of acute non-bacterial gastroenteritis in humans. the virus capsid is composed of a single 60 kda protein. in a previous study, the capsid protein of recombinant norwalk virus genogroup ii was expressed in an e. coli system and monoclonal antibodies were generated against it. the analysis of the reactivity of those monoclonal antibodies suggested that the n-terminal domain might contain more antigenic epitopes than the c-terminal domain. in the same study, two broa ...	2001	11710959
widespread environmental contamination with norwalk-like viruses (nlv) detected in a prolonged hotel outbreak of gastroenteritis.	a protracted outbreak of norwalk-like virus (nlv)-associated gastroenteritis occurred in a large hotel in north-west england between january and may 1996. we investigated the pattern of environmental contamination with nlv in the hotel during and after the outbreak. in the ninth week, 144 environmental swabs taken from around the hotel were tested for nlv by nested rt-pcr. the sites were categorized according to the likelihood of direct contamination with vomit/faeces. the highest proportion of ...	2000	11057964
norwalk-like virus sequences detected by reverse transcription-polymerase chain reaction in mineral waters imported into or bottled in switzerland.	norwalk-like viruses (nlvs) is a genus belonging to the caliciviridae. nlvs are transmitted by the fecal-oral and the aerosol route and are the most common cause of outbreaks of nonbacterial gastroenteritis. nlvs are responsible for an estimated 67% of all illnesses caused by known foodborne pathogens and for 96% of nonbacterial gastroenteritis in the united states. many outbreaks could be associated with the consumption of primarily or secondarily contaminated foods. to our knowledge, no epidem ...	2000	11079703
three nursing home outbreaks of norwalk-like virus in brisbane in 1999.	we report on three nursing home outbreaks of gastroenteritis in brisbane in 1999. the presence of norwalk-like virus (nlv) genogroup 2 was demonstrated by reverse transcription polymerase chain reaction (rt-pcr) in all three outbreaks. common findings of these investigations were rapid spread of the illness within the institutions and difficulties in identifying a common source. nursing home populations are vulnerable and it is important for each institution to have infection control policies in ...	2000	11022388
transmission of norwalk virus during football game.	during a college football game in florida, diarrhea and vomiting developed in many of the members of a north carolina team. the next day, similar symptoms developed in some of the players on the opposing team.	2000	11071673
norwalk virus strikes in pocahontas county.		2000	11077545
development of an immunomagnetic capture reverse transcription-pcr assay for the detection of norwalk virus.	norwalk virus (nv) is the prototype human virus of the family caliciviridae. a rapid immunomagnetic capture/reverse transcription-(imc/rt-)pcr assay was developed for the detection of nv. immunomagnetic capture (imc) utilizes paramagnetic beads coupled to a virus-specific antibody and allows separation of virus from contaminating materials and virus concentration in a single step. the detection limit of the developed assay was approximately 250-750 genomic equivalents/ml of 10% stool suspension. ...	2000	11011082
expression of recombinant capsid proteins of chitta virus, a genogroup ii norwalk virus, and development of an elisa to detect the viral antigen.	the second open reading frame (orf2) gene of the chitta virus (chv) was cloned to construct a recombinant baculovirus. the chv orf2 is predicted to encode a capsid protein of 535 amino acids (aa). chv showed a high aa identity in the capsid region with genogroup ii norwalk virus (nv) (65-85%), but a low aa identity with genogroup i nv (44-46%). phylogenetic analysis of the orf2 gene demonstrated that chv is genetically closely related to the hawaii virus included in genogroup ii nv. the recombin ...	2000	11021399
simultaneous detection and genotyping of "norwalk-like viruses" by oligonucleotide array in a reverse line blot hybridization format.	"norwalk-like viruses" (nlvs) are the most common cause of outbreaks of nonbacterial gastroenteritis worldwide. to date, the method most widely used for typing of nlv strains is sequencing and subsequent phylogenetic analysis of reverse transcription (rt)-pcr products, which has revealed the existence of stable distinct lineages (genotypes). this typing method is rather costly, not routinely used in clinical laboratories, and not very suitable for the analysis of large numbers of samples. theref ...	2000	10878050
evaluation of nine sets of pcr primers in the rna dependent rna polymerase region for detection and differentiation of members of the family caliciviridae, norwalk virus and sapporo virus.	norwalk virus and sapporo virus were approved as type species of the genus "norwalk-like viruses" and the genus "sapporo-like viruses," respectively, in the family caliciviridae. a total of 116 stool specimens containing norwalk virus (nv) or sapporo virus (sv) were tested by rt-pcr and southern hybridization to evaluate nine sets of pcr primers and seven internal oligonucleotide probes in the rna dependent rna polymerase region of nv and sv for detection and differentiation of viruses in the nv ...	2000	10888362
detection of small round structured viruses in stool specimens from outbreaks of gastroenteritis by electron microscopy and reverse transcription-polymerase chain reaction.	in testing 60 stool specimens small round structured virus (srsv) particles were detected in 35 (58%) specimens from all 17 outbreaks of gastroenteritis by electron microscopy (em), while srsv genes were found in 36 (60%) specimens from 15 outbreaks by reverse transcription-polymerase chain reaction (rt-pcr) by use of 2 primer pairs. specimens from 2 outbreaks were found srsv particles-positive by em but srsv genes-negative by rt-pcr. em remains the basic examination method for diagnosis of srsv ...	2000	10989693
distinct epidemiological patterns of norwalk-like virus infection.	norwalk-like viruses (nlv) are important economically as a cause of both sporadic gastroenteritis in the community and large outbreaks in hospitals and other institutional settings. despite the description of several antigenic types relatively little is known about the epidemiology of these individual types. nlvs were detected by electron microscopy in faecal specimens from 706 outbreaks of gastroenteritis that represented 68% of all outbreaks of non-bacterial gastroenteritis. these outbreaks to ...	2000	10935995
complete nucleotide sequence of the chiba virus genome and functional expression of the 3c-like protease in escherichia coli.	we cloned the genome rna of the chiba virus (chv; hu/nlv/chiba 407/1987/jp) and determined its complete nucleotide sequence. the genome is predicted to be a positive-sense, single-stranded rna of 7697 bases, excluding a poly(a) tract. comparison of the nucleotide and amino acid sequences with those of other members of the species norwalk virus (nv) revealed that chv belongs to genogroup i nv. the chv genome contains three open reading frames (orfs). a large 5'-terminal orf (orf1) encodes a polyp ...	2000	11118371
an improved method for the detection of norwalk-like caliciviruses in environmental samples.	an original magnetic beads rna capture was developed for the detection of norwalk-like virus by rt-pcr. the same oligonucleotide was used both for capture and reverse transcription of the viral rna. the optimization studies showed that the most important parameter for sensitivity is the biotin-binding capacity of the beads. this method was found to be efficient for eliminating inhibitors in sewage samples compared with the classic rt-pcr. moreover, the sensitivity was greatly enhanced, allowing ...	2000	11123547
infectious diseases of gastrointestinal tract in adolescents.	this article reviews the following gastrointestinal infections: esophagitis, gastritis, duodenitis including duodenal ulcers, and enteritis (gastroenteritis). the epidemiology, risk factors, microbiology and pathogenesis, diagnosis, treatment, morbidity/mortality, and prevention are discussed in relation to the most important pathogens. the symptoms and pathogenesis of esophagitis caused by candida albicans and herpes simplex are contrasted with the symptoms of esophagitis caused by helicobacter ...	2000	10916124
three-year study to assess human enteric viruses in shellfish.	the main pathogenic enteric viruses able to persist in the environment, such as hepatitis a virus (hav), norwalk-like virus (nlv), enterovirus (ev), rotavirus (rv), and astrovirus (av), were detected by reverse transcription-pcr and hybridization in shellfish during a 3-year study. oyster samples (n = 108), occasionally containing bacteria, were less frequently contaminated, showing positivity for av (17%), nlv (23%), ev (19%), and rv (27%), whereas mussel samples, collected in areas routinely i ...	2000	10919776
enteric virus infections and diarrhea in healthy and human immunodeficiency virus-infected children.	forty-three stool samples from 27 human immunodeficiency virus (hiv)-seropositive children and 38 samples from 38 hiv-negative children, collected during a 15-month period, were examined for enteric viruses. diagnostic assays included enzyme immunoassays for rotavirus, adenovirus, and norwalk virus; polyacrylamide gel electrophoresis for picobirnavirus and atypical rotavirus; and pcr for astrovirus and enterovirus. specimens from hiv-positive children were more likely than those of hiv-negative ...	2000	10921942
a series of outbreaks of food poisoning?	a series of independently occurring episodes which were notified individually as 'food poisoning' were, after investigation, linked to a common source water supply.	2000	10777225
norwalk-like virus as a cause of a gastroenteritis outbreak in a childcare centre.		2000	10937421
detection of sporadic cases of norwalk-like virus (nlv) and astrovirus infection in a single irish hospital from 1996 to 1998.	'norwalk-like viruses' (nlv) and astroviruses are recognised as the most important etiologic agents of viral gastroenteritis, excluding rotaviruses. however, neither of these two groups of viruses is routinely screened for in irish hospital laboratories.	2000	10942091
foodborne viral illness--status in australia.	norwalk-like virus contamination of oysters and orange juice, and hepatitis a virus contamination of oysters have been responsible for large outbreaks of foodborne viral disease in australia. rotavirus, adenovirus, astrovirus, parvovirus and other enteroviruses also contribute to the incidence of gastroenteritis in this country but the role of foods and waters in transmitting these viruses is unclear. protocols for the investigation, surveillance and reporting of foodborne viral illness require ...	2000	10946844
interaction of cellular proteins with the 5' end of norwalk virus genomic rna.	the lack of a susceptible cell line and an animal model for norwalk virus (nv) infection has prompted the development of alternative strategies to generate in vitro rnas that approximate the authentic viral genome. this approach has allowed the study of viral rna replication and gene expression. in this study, using mobility shift and cross-linking assays, we detected several cellular proteins from hela and caco-2 cell extracts that bind to, and form stable complexes with, the first 110 nucleoti ...	2000	10954557
[probe types of norwalk-like viruses genome detected by rt-pcr with seven primer pairs in yamanashi prefecture].	the reverse transcription-polymerase chain reaction (rt-pcr) gene assay, as well as electron microscopic examination, is commonly used to detect norwalk-like viruses (nlvs). types and number of primer pairs used are considered to be of critical importance for efficiency of the rt-pcr detection. this study was performed to determine primer pairs useful for the detection of nlvs. nlvs genes were detected by rt-pcr in 48 cases in yamanashi prefecture between december 1997 and march 2000. the probe ...	2000	10965659
molecular cloning, expression, and antigenicity of seto virus belonging to genogroup i norwalk-like viruses.	the viral capsid protein of the seto virus (sev), a japanese strain of genogroup i norwalk-like viruses (nlvs), was expressed as virus-like particles using a baculovirus expression system. an antigen detection enzyme-linked immunosorbent assay based on hyperimmune antisera to recombinant sev was highly specific to homologous sev-like strains but not heterologous strains in stools, allowing us type-specific detection of nlvs.	2000	10970413
foodborne infections vectored by molluscan shellfish.	foodborne diseases cause approximately 76 million illnesses, 325,000 hospitalizations, and 5000 deaths each year in the united states. the authors present and analyze information derived from epidemiologic investigations and surveillance systems on foodborne infections caused by consumption of molluscan shellfish. this review focuses on the bias in reporting of shellfish-vectored illness, prevention and control of such infections, the origin of recognized viral and bacterial etiologic agents, an ...	2000	10981028
evidence for airborne transmission of norwalk-like virus (nlv) in a hotel restaurant.	an outbreak of gastroenteritis followed a meal in a large hotel during which one of the diners vomited. the clinical features of the illness suggested norwalk-like virus (nlv, small round structured virus) infection, and this was confirmed by electron microscopy and reverse transcriptase polymerase chain reaction (rt-pcr) of stool samples. further characterization of the virus by nucleotide sequence analysis of the pcr amplicons revealed identical strains in all the affected individuals. the foo ...	2000	10982072
prevalence and genetic diversity of human caliciviruses (hucvs) in mexican children.	human caliciviruses (hucvs) contain two genera: "norwalk-like viruses" (nlvs) and "sapporo-like viruses" (slvs). the importance of the two genera as a cause of acute gastroenteritis of infants and children remains unknown. beginning in 1989, a birth cohort of children in mexico was enrolled and monitored for acute gastroenteritis. a subset of 115 diarrhea stool specimens from 76 children and 66 non-diarrhea stool specimens from 64 children was examined for hucvs by rt-pcr by using a primer pair ...	2000	11002251
mechanism of capsid assembly for an icosahedral plant virus.	capsids of spherical viruses share a common architecture: an icosahedral arrangement of identical proteins. we suggest that there may be a limited number of common assembly mechanisms for such viruses. previous assembly mechanisms were proposed on the basis of virion structure but were not rigorously tested. here we apply a rigorous analysis of assembly to cowpea chlorotic mottle virus (ccmv), a typical, small, positive-strand rna virus. the atomic resolution structure of ccmv revealed an interl ...	2000	11080492
interaction of recombinant norwalk virus particles with the 105-kilodalton cellular binding protein, a candidate receptor molecule for virus attachment.	norwalk virus (nv), responsible for outbreaks of acute gastroenteritis, comprises the species of the genus norwalk-like viruses in the family caliciviridae. although the study of the molecular biology of nv has been hampered by a lack of culture systems or small experimental animal models, virus-like particles (vlps) generated with recombinant baculoviruses harboring the capsid protein gene of nv provide a useful tool for investigating nv-cell interactions. in this study, the attachment of the r ...	2000	11090157
characterization of monoclonal antibodies generated against norwalk virus gii capsid protein expressed in escherichia coli.	the norwalk virus (nv) causes outbreaks of acute non-bacterial gastroenteritis in humans. the virus capsid is composed of a single 60 kda protein. the capsid protein of nv36 (genogroup ii, mexico virus type) was expressed in an escherichia coli system and ten monoclonal antibodies (mabs) were generated against it. the reactivity of these mabs was characterized using enzyme-linked immunosorbent assay (elisa) and western blot (wb) analysis towards 20 overlapping fragments of the nv36 capsid protei ...	2000	11145271
detection of 'norwalk-like viruses' in vellore, southern india.		2000	11198656
prevalence and genomic variation of norwalk-like viruses in central australia in 1995-1997.	norwalk-like viruses (nlvs) have now been found to be important causes of gastroenteritis amongst infants and young children as well as older children and adults. although detected, such viruses appeared not to be a major cause amongst infants and young children hospitalized with gastroenteritis in alice springs, central australia over the period january 1995-december 1997. nine nlv-positive cases were identified amongst stools from 360 different patients. from the nine cases however, eight diff ...	2000	11252671
investigation of an outbreak of gastroenteritis caused by norwalk-like virus, using solid phase immune electron microscopy.	in february 1993, 95 persons (47 patients and 48 staff members) were affected by an hospital outbreak of viral gastroenteritis. using direct electron microscopy (em) the causative agent was identified as a small round structured virus. this was confirmed as a norwalk-like virus using solid phase immune electron microscopy (spiem). of 94 stool samples examined, 12 (13%) samples containing small round structured viruses (srsv) were spiem positive for norwalk-like virus. a further 25 (27%) samples ...	2000	10662561
expression of recombinant norwalk-like virus capsid proteins using a bacterial system and the development of its immunologic detection.	the capsid protein of norwalk-like virus (nlv) isolates nlv-36 (mexico virus type, genogroup ii [gii]), nlv-21 (lordsdale virus type, gii), nlv-114 (untyped gii virus), and nlv-96-908 (ky89 virus type, gi) have been expressed in an escherichia coli system. the expressed recombinant nlv capsid proteins, fused with maltose binding protein (mbp-rv) and thioredoxin (trx-rv) in e. coli lysate, were analyzed using sodium dodecyl sulfate-polyacrylamide gel eletrophoresis. rabbit igg (r-igg) in hyperimm ...	2000	10686033
outbreaks of norwalk-like viral gastroenteritis--alaska and wisconsin, 1999.	norwalk-like viruses (nlvs) are the most common cause of epidemic gastroenteritis in the united states, resulting in illness in approximately 23 million persons each year . persons of all ages are affected because previous infection confers only short-term immunity. most nlv gastroenteritis outbreaks involve foodborne or person-to-person transmission. this report presents investigations of a foodborne nlv outbreak in alaska and person-to-person transmission in wisconsin.	2000	10738840
evaluation of f-specific rna bacteriophage as a candidate human enteric virus indicator for bivalve molluscan shellfish.	escherichia coli is a widely utilized indicator of the sanitary quality of bivalve molluscan shellfish sold for human consumption. however, it is now well documented that shellfish that meet the e. coli standards for human consumption may contain human enteric viruses that cause gastroenteritis and hepatitis. in this study we investigated using f-specific rna bacteriophage (frna bacteriophage) to indicate the likely presence of such viruses in shellfish sold for consumption. frna bacteriophage a ...	2000	10742200
selective accumulation may account for shellfish-associated viral illness.	from 1991 through 1998, 1,266 cases of shellfish-related illnesses were attributed to norwalk-like viruses. seventy-eight percent of these illnesses occurred following consumption of oysters harvested from the gulf coast during the months of november through january. this study investigated the ability of eastern oysters (crassostrea virginica) to accumulate indicator microorganisms (i.e., fecal coliforms, escherichia coli, clostridium perfringens, and f(+) coliphage) from estuarine water. one-w ...	2000	10742214
seroprevalence and seroincidence of norwalk-like virus infection among brazilian infants and children.	to determine the importance of norwalk-like viruses (nlvs) as pediatric pathogens in a developing country, the seroprevalence and seroincidence of this group of viruses in a cohort of children less than 4 years of age in an urban shantytown in northeastern brazil was examined. serum samples were collected approximately every 6 months from 135 children who were surveyed three times each week for diarrhea and vomiting. nlv igg was measured by an enzyme immunosorbent assay (eia) with recombinant no ...	2000	10745243
a diagnostic eia for detection of the prevalent srsv strain in united kingdom outbreaks of gastroenteritis.	small round structured viruses (srsvs) are the major cause of outbreaks of gastroenteritis in the uk. diagnosis is problematic due to insensitive electron microscopy (em) or technically demanding reverse transcription polymerase chain reaction (rt-pcr) techniques. we have studied outbreaks of non-bacterial gastroenteritis using an eia based upon recombinant capsid protein from the currently prevalent circulating strain of srsv (lordsdale genotype ii) and compared its performance against em and r ...	2000	10745245
identification of an epitope common to genogroup 1 "norwalk-like viruses".	a panel of 10 monoclonal antibodies (mabs) to recombinant norwalk virus (nv) capsid protein were tested in competition enzyme-linked immunosorbent assays. patterns of competition indicated that these mabs recognize six to eight epitopes covering five nonoverlapping regions of the capsid protein. a single epitope, recognized by nv mabs nv3901, nv3912, and nv2461 was found to occur in the majority of genogroup 1 (g1) but not genogroup 2 (g2) "norwalk-like viruses" (nlvs). this observation supports ...	2000	10747162
genetic polymorphism across regions of the three open reading frames of "norwalk-like viruses".	genomic characterization of norwalk-like human caliciviruses (nlvs) originating from outbreaks and sporadic cases of acute gastroenteritis has revealed surprisingly high levels of diversity, even in the rna polymerase gene, which is anticipated to be highly conserved. since information on antigenic relationship is limited, due to the lack of a tissue culture system for these viruses, strains mostly are described on the basis of their genetic relatedness. however, the lack of uniformly applied cr ...	2000	10752550
a foodborne outbreak of gastroenteritis associated with norwalk-like viruses: first molecular traceback to deli sandwiches contaminated during preparation.	in march 1998, an outbreak of acute gastroenteritis occurred among students at a texas university. overall, 125 ill students sought medical care. case-control studies revealed that illness was significantly associated with eating foods from the university's main cafeteria deli bar on 9 and 10 march. stool specimens from 9 (50%) of 18 ill students and samples of deli ham showed evidence of norwalk-like viruses (nlvs) by reverse-transcriptase (rt) polymerase chain reaction (pcr) assay. a food hand ...	2000	10753727
norwalk-like viral gastroenteritis outbreak in u.s. army trainees.	an outbreak of acute gastroenteritis hospitalized 99 (12%) of 835 u. s. army trainees at fort bliss, el paso, texas, from august 27 to september 1, 1998. reverse transcriptase polymerase chain reaction tests for norwalk-like virus were positive for genogroup 2. gastroenteritis was associated with one post dining facility and with soft drinks.	2000	10756159
molecular epidemiology of human enteric caliciviruses in the netherlands.	in the netherlands, illness due to norwalk-like viruses (nlvs) of the family caliciviridae is quite common. nlvs cause >80% of the outbreaks of gastroenteritis reported to municipal public health centers and at least 5% of the cases of gastroenteritis for which a general practitioner is consulted. in addition, up to 18% of community cases of gastroenteritis in the 1998/1999 winter season have been attributed to nlvs. patterns of disease activity differ remarkably, with "normal years, when outbre ...	2000	10804135
surveillance of viral gastroenteritis in japan: pediatric cases and outbreak incidents.	surveillance results from pediatric cases and outbreaks of viral gastroenteritis in japan are presented. in winter, both small round structured virus (srsv, or norwalk-like viruses) and rotavirus were detected from infants with gastroenteritis; however, in recent years, the prevailing time of srsv infection has preceded that of rotavirus infection. most nonbacterial gastroenteritis outbreaks were related to srsv infection, and >60% of the outbreaks were caused by contaminated food. in small-size ...	2000	10804136
epidemiology of calicivirus infections in sweden, 1994-1998.	outbreaks of acute gastroenteritis are frequently caused by caliciviruses. electron microscopy was used to search for these viruses in fecal samples from patients with acute gastroenteritis. of 5800 samples collected and analyzed from november 1994 to june 1998, 3700 were associated with outbreaks. a total of 676 outbreaks were analyzed, and viruses were found in 67%. caliciviruses, usually norwalk-like viruses (nlvs), were found in 407 (89%) of 455 outbreaks, while sapporo-like viruses were ide ...	2000	10804137
the impact of foodborne calicivirus disease: the minnesota experience.	the first outbreaks of norwalk virus gastroenteritis in minnesota were confirmed in 1982. since then, norwalk-like caliciviruses have been recognized to be the most common cause of foodborne disease outbreaks, accounting for 41% of all confirmed foodborne outbreaks in minnesota from 1981-1998. although laboratory confirmation of caliciviruses in stool samples was not attempted in most of these outbreaks, all conformed to epidemiologic criteria for defining outbreaks of norwalk virus. since 1996, ...	2000	10804138
cold weather seasonality of gastroenteritis associated with norwalk-like viruses.	norwalk-like viruses (nlvs) are the most common cause of acute nonbacterial gastroenteritis in adults, but little is known about their seasonality. the lack of specific diagnostic tools impeded study of these viruses in the past, and surveys using electron microscopy often grouped nlvs with other unrelated viruses. a search of the scientific literature found eight surveys of gastroenteritis, which were conducted for at least 1 year, that specifically identified nlvs. unpublished data from labora ...	2000	10804139
structural studies of recombinant norwalk capsids.	norwalk virus is the major cause of epidemic viral gastroenteritis in humans. attempts to grow this human virus in laboratory cell lines have been unsuccessful; however, the norwalk virus capsid protein, when expressed in insect cells infected with a recombinant baculovirus, spontaneously assembles into virus-like particles. the x-ray crystallographic structure of these recombinant norwalk particles has been determined to 3.4 a, using a 22-a electron cryomicroscopy structure as a phasing model. ...	2000	10804144
taxonomy of the caliciviruses.	the international committee on taxonomy of viruses (ictv) has recently approved several proposals submitted by the present caliciviridae study group. these proposals include the division of the family into 4 new genera designated lagovirus, vesivirus, "norwalk-like viruses (nlvs), and "sapporo-like viruses (slvs); the latter 2 genera were assigned temporary names until acceptable names can be determined by the scientific community. the genera have been further divided into the following species: ...	2000	10804145
immunity to calicivirus infection.	the evolution of our understanding of immunity to calicivirus infection, using norwalk virus as the prototype, is discussed in three stages: (1) "ancient times (1972-1978), when human volunteer studies prevailed, (2) the "middle ages (1978-1990), which were characterized by the development and implementation of solid-phase immunoassays based on native viral antigens, and (3) "modern times (1990 to present), which began with the cloning of the genome of the noncultivatable 8fiia strain of norwalk ...	2000	10804146
possible community immunity to small round structured virus gastroenteritis in a rural aboriginal community.	in april 1998 an outbreak of gastroenteritis affected visitors, but none of the aboriginal residents, at a territory health services luncheon in a rural aboriginal community in central australia. the epidemiological features and identification of small round structured virus (srsv) from two participants suggest that this was an outbreak caused by a srsv. the attack rate in the visitors who ate or drank food at the luncheon was 73% (11 of 15). seventeen aboriginal residents were interviewed, none ...	2000	10812750
members of the family caliciviridae (norwalk virus and sapporo virus) are the most prevalent cause of gastroenteritis outbreaks among infants in japan.	norwalk virus (nv) and sapporo virus (sv) were approved as type species of the genus norwalk-like viruses and the genus sapporo-like viruses, respectively, within the family caliciviridae. to clarify the importance of nv and sv as causes of gastroenteritis outbreaks in infants, stool samples obtained from 36 outbreaks of nonbacterial gastroenteritis that occurred during 1976-1995 in an infant home in sapporo, japan, were examined for diarrhea viruses using electron microscopy, enzyme immunoassay ...	2000	10837186
seroprevalence against norwalk-like human caliciviruses in beijing, china.	serum specimens from 1,109 individuals at different ages in beijing, china, were collected between april 1996 and march 1997 and tested for igg antibodies against human caliciviruses using enzyme immune assays (eias). baculovirus-expressed recombinant norwalk virus (rnv) and mexican virus (rmxv) capsid proteins were used as antigens. the seroprevalence was 89% for rnv and 91% for rmxv. similar seroprevalence between the two antigens was observed in individual age groups and both genders. infants ...	2000	10568770
viral agents associated with poult enteritis and mortality syndrome: the role of a small round virus and a turkey coronavirus.	intestinal samples from turkey poults affected with poult enteritis and mortality syndrome (pems) were examined for viruses by immune electron microscopy and double-stranded rna virus genome electropherotyping. turkey coronavirus (tcv), avian rotaviruses, reovirus, and a yet undefined small round virus (srv) were detected. the srv and tcv were isolated and propagated in turkey embryos. challenge of specific-pathogen-free turkey poults with srv, tcv, or both resulted in mortality and clinical res ...	2000	10879909
development of methods to detect "norwalk-like viruses" (nlvs) and hepatitis a virus in delicatessen foods: application to a food-borne nlv outbreak.	"norwalk-like viruses" (nlvs) and hepatitis a virus (hav) are the most common causes of virus-mediated food-borne illness. epidemiological investigations of outbreaks associated with these viruses have been hindered by the lack of available methods for the detection of nlvs and hav in foodstuffs. although reverse transcription (rt)-pcr methods have been useful in detecting nlvs and hav in bivalve mollusks implicated in outbreaks, to date such methods have not been available for other foods. to a ...	2000	10618226
[development of molecular tests for rapid detection of enteropathogens].	amplification of specific dna sequences by polymerase chain reaction (pcr), enables rapid, sensitive and direct, specific identification of pathogens at very low concentrations in clinical samples. studies in recent years have reported identification of several enteropathogens directly from stool samples by pcr. the amplification process includes the use of primers complementary to the dna sequences specific to the pathogen, thus relying on the pathogen's genotype, rather than its phenotype on w ...	2000	10883231
norwalk-like calicivirus genes in farm animals.	viruses closely related to norwalk-like viruses (nlvs) were recently found in stored stool samples from two calves (united kingdom and germany) and four pigs (japan), sparking discussions about the potential for zoonotic transmission. to investigate if nlvs are commonly present in farm animals, pooled stool samples from 100 pig farms, 48 chicken farms, 43 dairy cow herds, and 75 veal calf farms from the netherlands were assayed by reverse transcription- polymerase chain reaction amplification, u ...	2000	10653567
infantile convulsions with mild gastroenteritis.	the development of sensitive new molecular genetic techniques has led to the detection of rotavirus in cerebrospinal fluid, stools and throat swabs from patients with gastroenteritis with accompanying clinical symptoms similar to infantile benign convulsions. small round structured virus (srsv) has also been found in stools of patients with similar clinical symptoms by a new procedure. however, the mechanism by which these viral infections induce benign convulsions remains to be elucidated. the ...	2000	10891637
molecular epidemiology of outbreaks of gastroenteritis associated with small round structured viruses in germany in 1997/98.	the molecular epidemiology of small round structured viruses (srsvs) in germany was studied using fecal specimens from 16 srsv-associated gastroenteritis outbreaks in different parts of germany during 1997/1998 by reverse transcription-polymerase chain reaction (rt-pcr) and by sequencing of the orf1 and orf3 amplicons. the majority of the isolates clustered in one subtype and were closely related to published srsv sequences of genogroup ii.	2000	10795514
[magnitude of rainfall on viral contamination of the marine environment during gastroenteritis epidemics in human coastal population].	sewage treatments are not efficient to eliminate enteric microorganisms. viruses are able to persist and are discharged into the marine environment with treated effluents. few data are now available on the magnitude and the contributive processes of marine viral contamination. this work evaluates the relationship between the magnitude of rainfall and the viral contamination of the marine environment during winter epidemics of gastroenteritis in human coastal populations.	2000	10992111
rt-pcr identification and typing of astroviruses and norwalk-like viruses in hospitalized patients with gastroenteritis: evidence of nosocomial infections.	astroviruses (hastvs) and 'norwalk-like viruses' (nlv) are frequent causes of gastroenteritis worldwide, though no data on the strains in circulation or their prevalence is available for france.	2000	10996111
direct inhibitory effect of rotavirus nsp4(114-135) peptide on the na(+)-d-glucose symporter of rabbit intestinal brush border membrane.	the direct effect of a rotavirus nonstructural glycoprotein, nsp4, and certain related peptides on the sodium-coupled transport of d-glucose and of l-leucine was studied by using intestinal brush border membrane vesicles isolated from young rabbits. kinetic analyses revealed that the nsp4(114-135) peptide, which causes diarrhea in young rodents, is a specific, fully noncompetitive inhibitor of the na(+)-d-glucose symporter (sglt1). this interaction involves three peptide-binding sites per carrie ...	2000	11000215
the detection of small round-structured viruses in water and environmental materials.	a procedure for concentrating small round-structured viruses (srsvs) (norwalk-like viruses) from water and other environmental materials is described. primers based on the helicase region of the srsv genome were confirmed as specific by reaction with typed specimens, and used to detect virus in concentrates of unseeded and seeded samples. virus was detected in estuarine recreational water polluted by untreated sewage, although not in seawater samples taken some distance from outfall discharges. ...	2000	10856757
simplified procedure for detection of enteric pathogenic viruses in shellfish by rt-pcr.	epidemiological evidence linking the transmission of enteric viral disease to shellfish has been known for a long time. a variety of methods have been described for the detection of viral contaminants in shellfish using rt-pcr. however, these methods generally include numerous, often fastidious and time consuming steps for virus release from shellfish tissues and viral rna isolation. a simplified procedure based on the enzymatic liquefaction of shellfish digestive tissues without any mechanical ...	2000	11011076
genetic classification of "norwalk-like viruses..	reverse transcription-polymerase chain reaction has been used worldwide for the diagnosis of norwalk-like virus (nlv) infection, yet a commonly accepted genetic classification scheme has not been established. amino acid sequences from four regions of open-reading frame 2 (orf2) were used to analyze 101 nlv strains, including 2 bovine strains. on the basis of this analysis, a genetic classification scheme is proposed that differentiates 99 human strains into 2 major genetic groups consisting of 5 ...	2000	10804147
diagnosis of human caliciviruses by use of enzyme immunoassays.	the application of molecular technologies, such as the expression of viral proteins in baculovirus, has provided a powerful approach to the diagnosis of human calicivirus (hucv) infections. the baculovirus-expressed hucv capsid protein self-assembles into virus-like particles, providing excellent reagents for immunologic assays, such as enzyme immunoassays (eias). following the expression of the capsid protein of norwalk virus, the capsid proteins of 8 other hucv strains have been expressed in b ...	2000	10804148
detection of norwalk-like virus in shellfish implicated in illness.	in the 1990s, norwalk-like viruses (nlvs) were identified in patient specimens as the primary pathogen associated with shellfish-borne gastroenteritis in the united states. identification of these viruses from implicated shellfish has been difficult due to inefficient recovery of viruses, natural polymerase chain reaction (pcr) inhibitors in shellfish, and low virus contamination. recent improvements to the method of detecting nlvs in shellfish include enhanced processing of virus and shellfish ...	2000	10804149
the discovery of the 27-nm norwalk virus: an historic perspective.	in 1972, a 27-nm virus-like particle was discovered by use of immune electron microscopy (iem) in an infectious stool filtrate derived from an outbreak of gastroenteritis in an elementary school in norwalk, ohio. iem enabled the direct visualization of antigen-antibody interaction, as the particles were aggregated and coated by specific antibodies. this allowed the recognition and identification of a 27-nm virus-like particle that did not have a distinctive morphology, was low-titered, and was a ...	2000	10804141
organization and expression of calicivirus genes.	the application of molecular techniques to the characterization of caliciviruses has resulted in an extensive database of sequence information. this information has led to the identification of 4 distinct genera. the human enteric caliciviruses have been assigned to 2 of these genera. this division is reflected not only in sequence diversity but in a fundamental difference in genome organization. complete genome sequences are now available for 5 enteric caliciviruses and demonstrate that human a ...	2000	10804143
norwalk virus vaccines: challenges and progress.	human caliciviruses (hucvs) are the major cause of outbreaks of acute nonbacterial gastroenteritis throughout the world. an increasing recognition of the clinical significance of these viruses as human pathogens causing foodborne and waterborne disease indicates that an effective vaccine would be useful. this article reviews the current challenges that exist for the development of a vaccine for the hucvs as well as the status of development of a candidate vaccine. hucvs are viruses that exhibit ...	2000	10804150
multi-state outbreaks of acute gastroenteritis traced to fecal-contaminated oysters harvested in louisiana.	norwalk-like viruses (nlvs), or small round structured viruses, are known to cause acute gastroenteritis associated with eating contaminated shellfish. between 1993 and 1996, three oyster-related gastroenteritis outbreaks attributed to nlv occurred in louisiana. intensive trace-back and environmental investigations revealed that the overboard disposal of sewage by oyster harvesters into oyster-bed waters was the most likely source of contamination in at least two of the outbreaks. the small infe ...	2000	10804152
norwalk-like virus infection in military forces: epidemic potential, sporadic disease, and the future direction of prevention and control efforts.	the impact of norwalk-like virus (nlv) infection on military forces is evaluated in this report. nlvs were a major cause of both outbreaks and sporadic disease among crowded us ground troops in the 1991 war with iraq. nlvs also have been found to be a cause of acute gastroenteritis in other ground and shipboard deployments. four large outbreaks of acute gastroenteritis were investigated aboard us navy aircraft carriers between 1992 and 1997. in these outbreaks, nlvs were identified as the probab ...	2000	10804153