Publications

gastrointestinal outbreaks associated with norwalk virus in restaurants in vancouver, british columbia.		2002	12494826
a feline kidney cell line-based plaque assay for feline calicivirus, a surrogate for norwalk virus.	feline calicivirus (fcv) has been used by researchers as a surrogate for norwalk virus (nv), since they share a similar genomic organization, physicochemical characteristics, and are grouped in the same family, caliciviridae. unlike nv, however, fcv can grow in established cell lines and produce a syncytial form of cytopathic effect. in this report, we describe the development and standardization of a plaque assay for fcv using monolayers of an established line of feline kidney (crfk) cells in 1 ...	2003	12505630
norwalk-like viruses: when the runs can slow you down.		2003	12515788
[outbreaks of viral gastroenteritis, in particular due to the norwalk virus: an underestimated problem].	in the netherlands about 4 million people (283/1000) suffer from gastroenteritis every year, of which 500,000 cases are caused by 'norwalk-like viruses' (nlvs), formerly known as 'small round-structured viruses'. the reports of two outbreaks illustrate the difficulties in determining the cause and source of the infection. the course is usually mild, but complications may be serious and ought to be documented. vomiting and diarrhoea are the prominent signs and dehydration is the most common compl ...	2002	12518515
a modified cholera holotoxin ct-e29h enhances systemic and mucosal immune responses to recombinant norwalk virus-virus like particle vaccine.	in this study, we evaluated the potential of a genetically modified cholera toxin, ct-e29h as an adjuvant for recombinant norwalk virus like particle (nv-vlp) vaccine. this detoxified mutant, containing e to h substitution at amino acid 29 of the ct-a1 subunit, was administered with a recombinant norwalk virus like particle vaccine to balb/c mice by mucosal routes to monitor the induction of mucosal, humoral and cellular responses. we observed that a low dose of nv-vlp (5 microg) with the adjuva ...	2003	12531635
[evaluation of norwalk virus detection kit by enzyme immunoassay].	we briefly examined detection kit using the eia method for norwalk virus, and compared the results of the tests using the eia method with those using rt-pcr method. in reproducibility, an amount of variation was observed in data obtained from positive controls and in lower values. the sensitivity obtained from the eia method was about 300 times lower than that obtained from the rt-pcr method. results accordance ratio between eia method and rt-pcr method was 70%. this results discrepancy was pres ...	2002	12542393
microbial agents associated with waterborne diseases.	many classes of pathogens excreted in feces are able to initiate waterborne infections. there are bacterial pathogens, including enteric and aquatic bacteria, enteric viruses, and enteric protozoa, which are strongly resistant in the water environment and to most disinfectants. the infection dose of viral and protozoan agents is lower than bacteria, in the range of one to ten infectious units or oocysts. waterborne outbreaks of bacterial origin (particularly typhoid fever) in the developing coun ...	2002	12546197
evaluation of the nuclisens basic kit assay for detection of norwalk virus rna in stool specimens.	norwalk-like viruses (nlvs) are a genetically diverse group of human caliciviruses that are the most common cause of epidemic gastroenteritis and are detected typically in stool by reverse transcription (rt)-pcr or electron microscopy (em). the application of a rapid nucleic acid sequence-based amplification (nasba) assay for the detection of nlv rna in stool is described using the nuclisens basic kit. primers and probes for the nlv basic kit assay were based on the rna polymerase region of the ...	2003	12565163
incidence of enteric viruses in groundwater from household wells in wisconsin.	recent studies on the contamination of groundwater with human enteric viruses have focused on public water systems, whereas little is known about the occurrence of viruses in private household wells. the objective of the present study was to estimate the incidence of viruses in wisconsin household wells located near septage land application sites or in rural subdivisions served by septic systems. fifty wells in seven hydrogeologic districts were sampled four times over a year, once each season. ...	2003	12571044
major incidents. norwalk on the wild side.	an outbreak of the norwalk-like virus at an acute hospital in october affected 147 patients and 200 staff. it was brought under control within two weeks, following the establishment of a team to manage the incident. some day surgery was cancelled, but no inpatient operations were affected. the public was discouraged from visiting the hospital during the outbreak. local gps were co-operative about managing patients with the virus at home. some doctors came to work with symptoms, despite the trust ...	2003	12577823
evaluation of a commercial elisa for detecting norwalk-like virus antigen in faeces.	a commercially available enzyme immunoassay, the ideia norwalk-like virus (nlv) enzyme linked immunosorbent assay (elisa; dako cytomation, ely, uk) for detecting nlv antigen in faecal samples and determining the nlv genogroup was evaluated. the performance of the elisa was compared with that of electron microscopy and the reverse transcription polymerase chain reaction by testing a panel of faecal samples collected from patients involved in outbreaks of gastroenteritis. when compared with revers ...	2003	12589841
two nonoverlapping domains on the norwalk virus open reading frame 3 (orf3) protein are involved in the formation of the phosphorylated 35k protein and in orf3-capsid protein interactions.	expression of the norwalk virus open reading frame 3 (orf3) in spodoptera frugiperda (sf9) cells yields two major forms, the predicted 23,000-molecular-weight (23k) form and a larger 35k form. the 23k form is able to interact with the orf2 capsid protein and be incorporated into virus-like particles. in this paper, we provide mass spectrometry evidence that both the 23k and 35k forms are composed only of the orf3 protein. two-dimensional gel electrophoresis and phosphatase treatment showed that ...	2003	12610132
an outbreak of norwalk-like viral gastroenteritis in holidaymakers travelling to andorra, january-february 2002.	a retrospective cohort study was conducted to investigate an outbreak of norwalk-like viral gastroenteritidis that occurred in irish holidaymakers visiting andorra, in january-february 2002. preliminary results showed the risk exposure was higher for tourists who stayed in soldeu and consumed ice cubes in their drinks (or = 2.5, 95% ci [1.3-4.6)], after logistic regression and adjusting for sex and water consumption).	2003	12631977
comparative reduction of norwalk virus, poliovirus type 1, f+ rna coliphage ms2 and escherichia coli in miniature soil columns.	norwalk-like viruses (nlvs) are important agents of waterborne illness and have been linked to several groundwater-related outbreaks. the presence of human enteric viruses, in particular the presence of nlvs, is difficult to detect in the environment. consequently, surrogate organisms are typically used as indicators of viruses from faecal contamination. whether traditional bacterial indicators are reliable indicators for viral pathogens remains uncertain. few studies have directly compared mobi ...	2003	12639010
norwalk or noroviruses.		2003	12649997
viruses causing gastroenteritis.	acute gastroenteritis is one of the most common diseases in humans worldwide. viruses are recognized as important causes of this disease, particularly in children. since the norwalk virus was identified as a cause of gastroenteritis, the number of viral agents associated with diarrheal disease in humans has steadily increased. rotavirus is the most common cause of severe diarrhea in children under 5 years of age. astrovirus, calicivirus and enteric adenovirus are also important etiologic agents ...	2003	12667234
human susceptibility and resistance to norwalk virus infection.	infectious diseases have influenced population genetics and the evolution of the structure of the human genome in part by selecting for host susceptibility alleles that modify pathogenesis. norovirus infection is associated with approximately 90% of epidemic non-bacterial acute gastroenteritis worldwide. here, we show that resistance to norwalk virus infection is multifactorial. using a human challenge model, we showed that 29% of our study population was homozygous recessive for the alpha(1,2)f ...	2003	12692541
[nutrition and health--infections caused by food].	the annual incidence of food-borne infections in the netherlands is estimated to be 250,000 or more; registration, however, is lacking. meat, poultry, milk and eggs are contaminated primarily by intestinal animal commensals (salmonella, campylobacter, e. coli o157:h7, yersinia enterocolitica) or secondarily by animals, humans and the environment during processing (typhoid fever, shigella, listeria, clostridium, hepatitis a virus, norwalk virus, parasites). the guidelines for the prevention of co ...	2003	12701391
processing of norwalk virus nonstructural proteins by a 3c-like cysteine proteinase.	expression of norwalk virus nonstructural polyprotein precursor in vitro resulted in rapid cotranslational cleavage at specific sites. the cleavage products were similar to those previously identified for southampton virus, a highly related virus. we inactivated the virally encoded proteinase responsible for cleavage of the nonstructural polyprotein by mutation of the putative catalytic cysteine residue, which resulted in production of full-length polyprotein precursor. nv proteinase was express ...	2003	12706072
[norwalk virus].		2003	12718012
[norwalk virus infection].		2003	12722207
[outbreak of gastroenteritis caused by norwalk virus at a senior citizens assisted living facility in granada, spain].	the outbreaks of acute gastroenteritis caused by a virus are currently one of the health problems having the greatest impact on those living in senior citizen facilities. the objective of this study is that of investigating the causes of the start and contagion of an outbreak of acute gastroenteritis caused by a norwalk-like virus.	2003	12728663
the genome-linked protein vpg of the norwalk virus binds eif3, suggesting its role in translation initiation complex recruitment.	the positive-strand rna genomes of caliciviruses are not capped, but are instead covalently linked at their 5' ends to a viral protein called vpg. the lack of a cap structure typical of eukaryotic mrna and absence of an internal ribosomal entry site suggest that vpg may function in translation initiation on calicivirus rna. this hypothesis was tested by analyzing binding of norwalk virus vpg to translation initiation factors. the eif3d subunit of eif3 was identified as a binding partner of vpg b ...	2003	12773399
a multiplex reverse transcription-pcr method for detection of human enteric viruses in groundwater.	untreated groundwater is responsible for about half of the waterborne disease outbreaks in the united states. human enteric viruses are thought to be leading etiological agents of many of these outbreaks, but there is relatively little information on the types and levels of viruses found in groundwater. to address this problem, monthly samples from 29 groundwater sites were analyzed for 1 year for enteroviruses, hepatitis a virus, norwalk virus, reoviruses, and rotaviruses by multiplex reverse t ...	2003	12788711
studies of epidemiology and seroprevalence of bovine noroviruses in germany.	jena virus (jv) is a bovine enteric calicivirus that causes diarrhea in calves. the virus is approximately 30 nm in diameter and has a surface morphology similar to the human norwalk virus. the genome sequence of jv was recently described, and the virus has been assigned to the genus norovirus of the family caliciviridae: in the present study, the jv capsid gene encoded by open reading frame 2 was cloned into the baculovirus transfer vector pfastbac 1, and this was used to transform escherichia ...	2003	12791840
molecular epidemiology of norwalk-like virus (nlv) outbreaks occurring in kyushu japan between 1988 and 1993.	in nine outbreaks that occurred in the kyushu district between 1988 and 1993, we determined the nucleotide sequences of norwalk-like virus (nlv) gene fragments amplified by rt-pcr and molecular-epidemiologically analyzed the nlv epidemics. it is known that the nlv strains isolated from nine outbreaks of acute gastroenteritis, were divided into five clusters consisting of two genogroups. described by the year of outbreaks, the genogroup-1 (norwalk-like virus group) was prevalent in 1988, 1989, an ...	2003	12803379
[outbreaks of viral gastroenteritis, in particular due to the norwalk virus: an underestimated problem].		2003	12814028
norwalk virus infection and disease is associated with abo histo-blood group type.		2003	12825190
presence of viral genomes in mineral water: a sufficient condition to assume infectious risk?	appropriate interpretation of a positive reverse transcription-pcr is an important issue for virus-related health hazard assessment because viral genomes and infectious viruses exhibit different behavior patterns in water. in this context, using poliovirus 1 and feline calicivirus f9 as examples of enteric viruses, first we demonstrated that the stability of infectious viruses is greatly affected by the temperature of mineral water (10, 20, and 35 degrees c) and that, in contrast, temperature ha ...	2003	12839768
reduction of norwalk virus, poliovirus 1, and bacteriophage ms2 by ozone disinfection of water.	norwalk virus and other human caliciviruses (noroviruses) are major agents of gastroenteritis, and water is a major route of their transmission. in an effort to control norwalk virus in drinking water, norwalk virus reduction by bench-scale ozone disinfection was determined using quantitative reverse transcription (rt)-pcr for virus assays. two other enteric viruses, poliovirus 1 and coliphage ms2, were included for comparison, and their reductions were assayed by infectivity assays as well as b ...	2003	12839770
communicable disease and health protection quarterly review: october to december 2002.		2003	12848412
humoral, mucosal, and cellular immune responses to oral norwalk virus-like particles in volunteers.	norwalk virus-like particles (vlps), made from recombinant capsid protein, are a promising vaccine. thirty-six healthy adult volunteers received 250 microg (n = 10), 500 microg (n = 10), or 2000 microg (n = 10) of orally administered vlp or placebo (n = 6). all vaccinees developed significant rises in iga anti-vlp antibody-secreting cells. ninety percent who received 250 microg developed rises in serum anti-vlp igg; neither the rates of seroconversion nor geometric mean titers increased at the h ...	2003	14499247
inhibition of attachment of virions of norwalk virus to mammalian cells by soluble histone molecules.	viral infection is usually initiated by the binding of virus particles to specific receptor molecule(s) on the host cell surface. blocking of this step prevents the following step, penetration into the cell. in the present study, we investigated the virus-cell interactions of virions of norwalk virus (nv), a major etiological agent for viral diarrhea. we found that histone was an extremely strong nv-binding protein. histone h1, a heterologous histone molecule, appeared to be able to interact not ...	2003	14505080
in vitro proteolytic processing of the md145 norovirus orf1 nonstructural polyprotein yields stable precursors and products similar to those detected in calicivirus-infected cells.	the md145-12 strain (gii/4) is a member of the genus norovirus in the caliciviridae and was detected in a patient with acute gastroenteritis in a maryland nursing home. the open reading frame 1 (orf1) (encoding the nonstructural polyprotein) was cloned as a consensus sequence into various expression vectors, and a proteolytic cleavage map was determined. the virus-encoded cysteine proteinase mediated at least five cleavages (q(330)/g(331), q(696)/g(697), e(875)/g(876), e(1008)/a(1009), and e(118 ...	2003	14512545
detection, quantitation, and phylogenetic analysis of noroviruses in japanese oysters.	noroviruses (nvs) cause many cases of oyster- or clam-associated gastroenteritis in various countries. we collected 191 samples from japanese oysters intended for raw consumption that had been harvested from the sea in two different areas between december 2001 and february 2002. to detect, quantitate, and phylogenetically analyze the nv genome in purified concentrates from the stomachs and digestive diverticula of these oysters, we amplified the nv capsid gene by reverse transcription-pcr. phylo ...	2003	14532025
debugging your travel plans.		2003	14533593
the 3' end of norwalk virus mrna contains determinants that regulate the expression and stability of the viral capsid protein vp1: a novel function for the vp2 protein.	norwalk virus (nv) is the prototype strain of a group of noncultivable human caliciviruses responsible for epidemic outbreaks of acute gastroenteritis. the capsid protein vp1 is synthesized from a subgenomic rna that contains two open reading frames (orfs), orf2 and orf3, and the 3' untranslated region (utr). orf2 and orf3 code for the capsid protein (vp1) and a small structural basic protein (vp2), respectively. we discovered that the yields of virus-like particles (vlps) composed of vp1 are si ...	2003	14557646
norwalk virus nonstructural protein p48 forms a complex with the snare regulator vap-a and prevents cell surface expression of vesicular stomatitis virus g protein.	norwalk virus (nv), a reference strain of human calicivirus in the norovirus genus of the family caliciviridae, contains a positive-strand rna genome with three open reading frames. orf1 encodes a 1,789-amino-acid polyprotein that is processed into nonstructural proteins that include an ntpase, vpg, protease, and rna-dependent rna polymerase. the n-terminal protein p48 of orf1 shows no significant sequence similarity to viral or cellular proteins, and its function in the human calicivirus replic ...	2003	14557663
the healthy traveler: cruising past infection.		2003	14619804
la, ptb, and pab proteins bind to the 3(') untranslated region of norwalk virus genomic rna.	noroviruses are human enteric caliciviruses for which no cell culture is available. consequently, the mechanisms and factors involved in their replication have been difficult to study. in an attempt to analyze the cis- and trans-acting factors that could have a role in nv replication, the 3(')-untranslated region of the genome was studied. use of zuker's mfold-2 software predicted that nv 3(')utr contains a stem-loop structure of 47 nts. proteins from hela cell extracts, such as la and ptb, form ...	2003	14623338
simultaneous detection of enteric viruses by multiplex real-time rt-pcr.	a multiplex real-time rt-pcr protocol for the simultaneous detection of noroviruses ("norwalk-like viruses") of genogroups i and ii, human astroviruses and enteroviruses is described. the protocol was developed and evaluated using the lightcycler and corresponding sybr green reagents. new primers were designed within conserved genome regions to optimize the detection range of virus subtypes of each genus. to enable the development of a multiplex pcr assay within one tube (capillary), similar mas ...	2004	14656455
[incidence and prevalent types of norwalk virus, sapporo virus and human astrovirus in pediatric gastroenteritis in hiroshima prefecture].	the incidence and prevalent types of norwalk virus (nv), sapporo virus (sv), and human astrovirus (hastv) in pediatric gastroenteritis in hiroshima prefecture were investigated in 7 cold seasons, between 1995/96 and 2001/02. the incidences of nv, sv, and hastv were 23.6% ranging from 16.3 to 34.4, 2.5% ranging from 1.5 to 4.7, and 3.2% ranging from 1.5 to 6.0, respectively. the peak of the incidence of nv was found in november and december. no accumulation of monthly incidence in sv or hastv was ...	2003	14672009
ultrastructure changes induced by dry film formation of a trisodium phosphate blend, antimicrobial solution.	trisodium phosphate (tsp) has been reported to have antimicrobial activity and is approved by the u.s. department of agriculture for use in food processing applications. a novel (u.s. patent 6,184,198), antimicrobial solution containing a blend of tsp, sodium bicarbonate, and sodium carbonate (tsp blend) has demonstrated effective inhibition of microbial contamination in a broad spectrum of applications. this high-resolution cold field emission scanning electron microcopy (lvsem) investigation d ...	2003	14696975
norwalk virus: a need for more awareness.		2003	14700024
in the public's view... vomiting on the high seas.		2003	14702792
a sybr green, real-time rt-pcr method to detect and quantitate norwalk virus in stools.	a simple, single tube, hot start, real-time reverse transcription-pcr (rt rt-pcr) technique using sybr green fluorescence was developed for the detection of genogroup i, cluster 1 norwalk virus (nv) in stools. sample dilution and heat release of viral rna was effective as an alternative to more complex procedures to extract viruses from stool specimens. real-time rt-pcr was applied to 68 stool isolates from patients participating in a nv volunteer study. first derivative melt curves were used to ...	2004	14715308
crystal structure of norwalk virus polymerase reveals the carboxyl terminus in the active site cleft.	norwalk virus is a major cause of acute gastroenteritis for which effective treatments are sorely lacking. to provide a basis for the rational design of novel antiviral agents, the main replication enzyme in norwalk virus, the virally encoded rna-dependent rna polymerase (rdrp), has been expressed in an enzymatically active form, and its structure has been crystallographically determined both in the presence and absence of divalent metal cations. although the overall fold of the enzyme is simila ...	2004	14764591
prevalence of infection with waterborne pathogens: a seroepidemiologic study in children 6-36 months old in san juan sacatepequez, guatemala.	water and sanitation interventions in developing countries have historically been difficult to evaluate. we conducted a seroepidemiologic study with the following goals: 1) to determine the feasibility of using antibody markers as indicators of waterborne pathogen infection in the evaluation of water and sanitation intervention projects; 2) to characterize the epidemiology of waterborne diarrheal infections in rural guatemala, and 3) to measure the age-specific prevalence of antibodies to waterb ...	2004	14971703
norovirus capture with histo-blood group antigens reveals novel virus-ligand interactions.	noroviruses are genetically diverse, uncultivable, positive-sense rna viruses and are the most common cause of epidemic acute gastroenteritis in humans in the united states. recent studies of norovirus attachment in vitro by using recombinant virus-like particles (vlps) suggest that various norovirus strains exhibit different patterns of attachment to abh histo-blood group antigens, which are carbohydrate epitopes present in high concentrations on mucosal cell surfaces of the gut. however, attac ...	2004	14990722
[preliminary study of human calicivirus infection in guangzhou].	to investigate of human calicivirus (hucv) infection in the children of guangzhou, the capital of guangdong province at china, and conduct preliminary study of the prevalence of the virus.	2004	15041544
emerging food pathogens and bacterial toxins.	many different foodborne diseases have been described. for example, shigella bacteria, hepatitis a virus and norwalk virus were shown as a unwashed hands microorganisms, but pathogen campylobacter and escherichia coli were named as raw and undercooked meat and poultry or raw milk and untreated water born bacteria. however, two of them: listeria monocytogenes and yersinia enterocolitica are known as growing at refrigerator temperatures. essential virulence determinants of listeria monocytogenes p ...	2003	15058810
norwalk virus n-terminal nonstructural protein is associated with disassembly of the golgi complex in transfected cells.	norwalk virus is the prototype strain for members of the genus norovirus in the family caliciviridae, which are associated with epidemic gastroenteritis in humans. the nonstructural protein encoded in the n-terminal region of the first open reading frame (orf1) of the norwalk virus genome is analogous in gene order to proteins 2a and 2b of the picornaviruses; the latter is known for its membrane-associated activities. confocal microscopy imaging of cells transfected with a vector plasmid that pr ...	2004	15078964
norwalk precipitates severe lithium toxicity.		2004	15101507
transmission of acute infectious nonbacterial gastroenteritis to volunteers by oral administration of stool filtrates. 1971.		2004	15143483
the p domain of norovirus capsid protein forms dimer and binds to histo-blood group antigen receptors.	noroviruses (nvs) are the most important pathogen of epidemic nonbacterial gastroenteritis. the recent finding that nvs recognize human histo-blood group antigens (hbgas) as receptors provided a new approach to study the pathogenesis of nvs. using computational and site-directed mutagenesis approaches, our investigators previously identified a plausible binding pocket in the p domain of the nv capsids. in this study, we further characterize the role of the p domain in the interaction with human ...	2004	15163716
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 ...	2004	15163740
norovirus disease: changing epidemiology and host susceptibility factors.	noroviruses cause the majority of acute viral gastroenteritis cases that occur worldwide. the increased recognition of noroviruses as the cause of outbreaks and sporadic disease is due to the recent availability of improved norovirus-specific diagnostics. transmission of these viruses is facilitated by their high prevalence in the community, shedding of infectious virus particles from asymptomatic individuals and the high stability of the virus in the environment. currently, the spectrum of clin ...	2004	15165606
[three kinds of viruses isolated from diarrhea patients of infants and preschool children in fuzhou city].		2004	15231185
nisin-controlled expression of norwalk virus vp60 protein in lactobacillus casei.	a food-grade strain with nisrk stably integrated into the genome, was constructed in order to implement the nisin-controlled expression system (nice) in lactobacillus casei atcc393. expression of beta-glucuronidase (gus) reporter gene was employed to optimize the system, which has been successfully used to produce the main antigenic protein from norwalk virus, opening new perspectives for producing edible vaccines.	2004	15321687
development of homologous viral internal controls for use in rt-pcr assays of waterborne enteric viruses.	enteric viruses often contaminate water sources causing frequent outbreaks of gastroenteritis. reverse transcription-polymerase chain reaction (rt-pcr) assays are commonly used for detection of human enteric viruses in environmental and drinking water samples. rt-pcr provides a means to rapidly detect low levels of these viruses, but it is sensitive to inhibitors that are present in water samples. inhibitors of rt-pcr are concentrated along with viruses during sample processing. while procedures ...	2004	15350731
histo-blood group antigen and human milk oligosaccharides: genetic polymorphism and risk of infectious diseases.	abh and lewis antigens are carbohydrates present on gut epithelial cells. these antigens provide diversity within the human population. their biosynthesis largely is controlled by the enzyme products of alleles at the abo, fut2 and fut3 loci. we have shown that norwalk virus (nv) uses structures based on h type 1 as its primary receptor. norwalk virus is the prototype of human caliciviruses, which collectively are responsible for the majority of gastroenteritis outbreaks in people of all ages. i ...	2004	15384573
[spread of viruses through the food chain].	food associated viruses are responsible for a high number of infectious diseases in man, mainly gastroenteritis and hepatitis. the three most important viral agents are noroviruses (nv) (formerly known as norwalk-like viruses), rotavirus (rv) and hepatitis a-virus (hav). the numbers of infections in man were in 2002 according to the robert koch-institut for nv and rv 50,000, respectively, and for hav 1,500, slightly decreasing in 2003. the rate of foodborne infections caused by viruses can only ...	2004	15469057
human milk contains elements that block binding of noroviruses to human histo-blood group antigens in saliva.	noroviruses (nvs) recognize human histo-blood group antigens (hbgas) as receptors. we characterized the interaction of human milk samples with recombinant virus-like particles representing va387, norwalk, va207, and moh. milk samples from 60 healthy women were tested for human hbgas and for their ability to block the binding of nvs. fifty-four women were secretors (se+), and 6 were nonsecretors (se-). no women had detectable a or b antigens in their milk samples. all 54 se+ milk samples, but 0 o ...	2004	15499543
diagnosis of norwalk virus infection by indirect enzyme immunoassay detection of salivary antibodies to recombinant norwalk virus antigen.	simple diagnostic tests are needed for the detection of norovirus (nov) outbreaks. salivary antibody assays provide an attractive alternative to collecting and testing serum or stool samples. antibodies to norwalk virus (nv) in oral fluid samples were compared with nv antibodies in serum collected from 38 volunteers challenged with nv inoculum. pre- and postchallenge (day 4, 8, 14, and 21) saliva and serum samples were examined by enzyme immunoassay (eia) using recombinant nv antigen. of 18 infe ...	2004	15539501
[norwalk virus and noro virus].	norwalk virus and noro virus are members of the caliciviridae. these viruses are morphological similarity in each other and shows small round structure. these viruses also are well known as main pathogens of acute infectious gastroenteritis. clinical features include an incubation period of 24 of 48 hours and illness period of 18 to 72 hours with vomiting and diarrhea in most patients and high secondary attack rates. oral transmitted infection occurs contaminated water and foods. in our country, ...	2003	15552834
evaluation of an antigen capture elisa based on recombinant mexico virus capsid protein.	the diagnosis of gastrointestinal infections caused by small round structured viruses (srsv) has relied upon electron microscopy and antigen/antibody assays based on norwalk virus. we investigated cases of gastroenteritis associated with srsvs employing a new sandwich enzyme-linked immunosorbent assay (elisa) using hyperimmune animal anti-sera against recombinant mexico virus capsid protein (rmxv).	1996	15566858
viruses that multiply in the gut and cause endemic and epidemic gastroenteritis.	acute infectious diarrhea in young children is a leading cause of morbidity and mortality in developing countries. even in developed countries, infectious enteritis is second only to respiratory infections as a cause of morbidity in early childhood.	1996	15566895
evolutionary trace residues in noroviruses: importance in receptor binding, antigenicity, virion assembly, and strain diversity.	noroviruses cause major epidemic gastroenteritis in humans. a large number of strains of these single-stranded rna viruses have been reported. due to the absence of infectious clones of noroviruses and the high sequence variability in their capsids, it has not been possible to identify functionally important residues in these capsids. consequently, norovirus strain diversity is not understood on the basis of capsid functions, and the development of therapeutic compounds has been hampered. to det ...	2005	15596848
experimental norovirus infections in non-human primates.	noroviruses, with norwalk virus as the prototype strain, are the most common cause of viral gastroenteritis in people of all ages. limited information on the immunology of norovirus infections has been obtained by studies both in the natural setting and in experimentally infected volunteers. interpretation of these studies is difficult due to the lack of information on the history of norovirus exposure and the cross-reactivity of antibodies. an animal model for norovirus infections would be impo ...	2005	15602728
[screening for calicivirus in children under five years of age, in an abidjan low-income district].		2004	15603932
association of histo-blood group antigens and susceptibility to norovirus infections.	noroviruses (novs) are the leading cause of viral gastroenteritis in humans of all ages. challenge studies that used the nov prototype strain norwalk virus (nv) have shown that some individuals are not susceptible to infection, suggesting the absence of a receptor. recent studies have identified histo-blood group antigens (hbgas) as possible receptors. being a nonsecretor and presence of hbga type b were associated with protection against infection with nv, a genogroup (gg) i nov.	2005	15688291
seroprevalence of noroviruses in swine.	noroviruses (nvs) are important human pathogens that cause acute gastroenteritis. genetically related animal enteric nvs have also been described, but there is no evidence of interspecies transmission of nvs. in this study we characterized antibody prevalence among domestic pigs by using recombinant capsid antigens of two human nvs (norwalk and hawaii) and one swine nv (sw918) that is genetically related to gii human nvs. recombinant sw918 capsid protein expressed in baculovirus self-assembled i ...	2005	15695660
cellular and humoral immunity following snow mountain virus challenge.	little is known about the immune response to noroviruses. to elucidate the immunobiology of norovirus infection in humans, 15 volunteers were challenged with snow mountain virus (smv), a genogroup 2 norovirus. we assessed the cellular and humoral immune response and infection by analyzing stool, serum, saliva, and peripheral blood mononuclear cell (pbmc) responses pre- and postchallenge. in contrast to norwalk virus (nv), smv infection was not dependent upon blood group secretor status. nine of ...	2005	15709009
virus-like particle expression and assembly in plants: hepatitis b and norwalk viruses.	expression of vaccine antigens in plants and delivery via ingestion of transgenic plant material has shown promise in numerous pre-clinical animal studies and in a few clinical trials. a number of different viral antigens have been tested, and among the most promising are those that can assemble virus-like particles (vlp), which mimic the form of authentic virions and display neutralizing antibody epitopes. we have extensively studied plant expression, vlp assembly, and immunogenicity of hepatit ...	2005	15734055
plant-derived vaccines against diarrheal diseases.	transgenic plants present a novel system for both production and oral delivery of vaccine antigens. production of protein antigen in food plants is substantially cheaper than production in bacterial, fungal, insect cell, or mammalian cell culture. edible plants themselves can also serve as the oral vaccine delivery system. phase-1 studies of raw transgenic potatoes expressing the b subunit of escherichia coli heat labile enterotoxin (lt-b), potatoes expressing norwalk virus capsid protein, and d ...	2005	15734057
detection of serum antibodies to bovine norovirus in veterinarians and the general population in the netherlands.	the close genetic relationship of human and animal strains of norovirus has raised the possibility of transmission of noroviruses from animals to humans and may explain the emergence of certain norovirus strains. to assess if exposure to bovine noroviruses (nov) might result in infection in humans, an enzyme immunoassay (eia) was designed and validated in order to detect antibodies against bovine norovirus. this and two other eias were used to test sera from 210 veterinarians and 630 matched pop ...	2005	15779045
microbial partitioning to settleable particles in stormwater.	the degree to which microbes in the water column associate with settleable particles has important implications for microbial transport in receiving waters, as well as for microbial removal via sedimentation (i.e. detention basins). the partitioning behavior of several bacterial, protozoan and viral indicator organisms is explored in three urban streams under both storm and dry weather conditions. the fraction of organisms associated with settleable particles in stormwater is estimated through u ...	2005	15899275
identification of genogroup i and genogroup ii broadly reactive epitopes on the norovirus capsid.	norwalk virus, a member of the family caliciviridae, is an important cause of acute epidemic nonbacterial gastroenteritis. norwalk and related viruses are classified in a separate genus of caliciviridae called norovirus, which is comprised of at least three genogroups based on sequence differences. many of the currently available immunologic reagents used to study these viruses are type specific, which limits the identification of antigenically distinct viruses in detection assays. identificatio ...	2005	15919896
replication and packaging of norwalk virus rna in cultured mammalian cells.	human noroviruses, the most common cause of nonbacterial gastroenteritis, are characterized by high infectivity rate, low infectious dose, and unusually high stability outside the host. however, human norovirus research is hindered by the lack of a cell culture system and a small animal model of infection. norwalk virus (nv) is the prototype strain of human noroviruses. we report here replication of nv viral rna and its packaging into virus particles in mammalian cells by intracellular expressio ...	2005	16002473
norwalk virus infection associates with secretor status genotyped from sera.	abo histo-blood group type and secretor status are two genetically determined factors that contribute to resistance and susceptibility to norwalk virus (nv). archived serum samples but not saliva samples are available from nv and many other norovirus challenge studies and outbreaks. a person's abo phenotype is easily determined from their archived sera, but the individual's secretor phenotype cannot easily be ascertained without saliva. we now report that a person's secretor genotype can also be ...	2005	16032732
the influence of ionic strength on the interaction of viruses with charged surfaces under environmental conditions.	the influence of ionic strength on the electrostatic interaction of viruses with environmentally relevant surfaces was determined for three viruses, ms2, q beta, and norwalk. the virus is modeled as a particle comprised of ionizable amino acid residues in a shell surrounding a spherical rna core of negative charge, these charges being compensated for by a coulomb screening due to intercalated ions. a second model of the virus involving surface charges only is included for comparison. surface pot ...	2006	16083898
influence of the combined abo, fut2, and fut3 polymorphism on susceptibility to norwalk virus attachment.	the binding of norwalk virus (nv) recombinant capsids was tested in a panel of saliva samples collected from 96 donors with different abo, secretor, and lewis phenotypes. as previously reported, binding occurred specifically to saliva from secretors, regardless of their lewis phenotype status. blood group b saliva was poorly recognized, whereas binding to blood group o saliva was higher and binding to blood group a saliva was highest. transfection of either blood group a or b enzyme into h epito ...	2005	16107962
proportion of sporadic gastroenteritis cases caused by rotavirus, norovirus, adenovirus and bacteria in japan from january 2000 to december 2003.	many kinds of virus and bacterium have been identified as pathogens that cause sporadic gastroenteritis (sg). among the pathogens, rotavirus (rv), norovirus (nv; previously known as norwalk-like virus), and adenovirus (adv) types 40/41 have been considered as the prevalent viruses implicated in the aetiology of childhood gastroenteritis. in the present study, we attempted to estimate monthly proportions of sg cases caused by the viral agents (rv, nv, adv and other viruses (ov)) and bacterial age ...	2005	16113503
contemporary issues in food allergy: seafood toxin-induced disease in the differential diagnosis of allergic reactions.	seafood, including fish, shrimp, lobster, crab, crayfish, mussel, and clam are among the most frequent causes of food allergy. seafood poisoning, including reactions to natural toxins, frequently masquerades as an allergic reaction on presentation. ingestion of contaminated shellfish results in a wide variety of symptoms, depending on the toxins present, their concentrations in the shellfish, and the amount of contaminated shellfish consumed. five types of shellfish poisoning have been identifie ...	2005	16119031
epitopes in the p2 domain of norovirus vp1 recognized by monoclonal antibodies that block cell interactions.	noroviruses cause the majority of epidemic outbreaks of acute viral gastroenteritis worldwide. human norovirus strains do not grow in cell culture, but recent carbohydrate binding, sequence and structural analyses have begun to define functional domains in the norovirus capsid that may be conserved among multiple antigenic types. the purpose of this study was to localize domains and define sequences in the major capsid protein vp1 that are important for cell interactions. monoclonal antibodies t ...	2005	16186235
bile-salt-stimulated lipase and mucins from milk of 'secretor' mothers inhibit the binding of norwalk virus capsids to their carbohydrate ligands.	breast-feeding-associated protection against calicivirus diarrhoea is associated with the presence of high levels of 2-linked oligosaccharides in mother's milk, and human calicivirus strains including the nv (norwalk virus) use gut 2-linked fucosylated glycans as receptors, suggesting the presence of decoy receptors in milk. our aim was to analyse the ability of human milk to inhibit the attachment of rnv vlps (recombinant nv-like particles) to their carbohydrate ligands and to characterize pote ...	2006	16266293
molecular and epidemiologic trends of caliciviruses associated with outbreaks of acute gastroenteritis in the united states, 2000-2004.	between july 2000 and june 2004, fecal specimens from 270 outbreaks of acute gastroenteritis were sent to the centers for disease control and prevention by local or state health departments for calicivirus testing. of the 226 outbreaks that met the criteria for inclusion in the present study, caliciviruses were detected in 184 (81%) by reverse-transcription polymerase chain reaction and nucleotide sequencing. nursing homes, retirement centers, and hospitals were the most frequently reported sett ...	2006	16388489
persistence of caliciviruses on environmental surfaces and their transfer to food.	the noroviruses (nov) are a common cause of human gastroenteritis whose transmission by foodborne routes is well documented. fecally contaminated surfaces are likely to contribute to this foodborne transmission and to the propagation of viral disease outbreaks. the purpose of this study was to (i) investigate the stability of nov on various food preparation surfaces; and (ii) evaluate the degree of virus transfer from these surfaces to a model-ready-to-eat (rte) food. for the virus persistence e ...	2006	16473426
detection of norovirus capsid proteins in faecal and food samples by a real time immuno-pcr method.	to develop a sensitive real time immuno-polymerase chain reaction (rti-pcr) method for detecting norovirus (nv) capsid protein in food samples.	2006	16478496
epidemiology, etiology and pathophysiology of traveler's diarrhea.	traveler's diarrhea (td) is the most frequent health problem in travelers to developing countries. several personal and environmental risk factors are at the basis of td acquisition and are discussed in this paper. td is caused by a wide range of infectious organisms, etec and eaec bacteria strains being the main enteropathogens incriminated in td. other causative bacteria are: shigella spp., campylobacter spp., vibrio spp., aeromonas spp., salmonella spp., and plesiomonas spp. parasite species ...	2006	16498258
x-ray crystallographic structure of the norwalk virus protease at 1.5-a resolution.	norwalk virus (nv), a member of the caliciviridae family, is the major cause of acute, epidemic, viral gastroenteritis. the nv genome is a positive sense, single-stranded rna that encodes three open reading frames (orfs). the first orf produces a polyprotein that is processed by the viral cysteine protease into six nonstructural proteins. we have determined the structure of the nv protease to 1.5 and 2.2 a from crystals grown in the absence or presence, respectively, of the protease inhibitor ae ...	2006	16641296
the vpgpro protein of turnip mosaic virus: in vitro inhibition of translation from a ribonuclease activity.	a role for viral encoded genome-linked (vpg) proteins in translation has often been suggested because of their covalent attachment to the 5' end of the viral rna, reminiscent of the cap structure normally present on most eukaryotic mrnas. we tested the effect of turnip mosaic virus (tumv) vpgpro on translation of reporter rnas in in vitro translation systems. the presence of vpgpro in either wheat germ extract or rabbit reticulocyte lysate systems lead to inhibition of translation. the inhibitio ...	2006	16647732
multivalent norovirus vaccines induce strong mucosal and systemic blocking antibodies against multiple strains.	noroviruses are important agents of human gastroenteritis characterized by extensive sequence variation in the major capsid structural protein that likely encodes critical antigenic determinants of protective immunity. the lack of an infection model has limited detailed characterizations of viral antigenic relationships and identification of the essential components for protective immunity. this information would contribute to efficacious vaccine design against a broad array of norovirus strains ...	2006	16650512
conformational stability and disassembly of norwalk virus-like particles. effect of ph and temperature.	greater than 99% of the norwalk virus (nv) capsid consists of 180 copies of a single 58-kda protein. recombinantly expressed monomers self-assemble into virus-like particles (vlps) with a well defined icosahedral structure. nv-vlps are an appropriate vaccine antigen since the antigenic determinants of the parent virion are preserved. they also constitute very simple models to study the mechanisms of assembly and disassembly of viral capsids. this work examines the inherent stability of nv-vlps o ...	2006	16675449
health risks of enteric viral infections in children.	children are at a greater risk of infections from serious enteric viral illness than adults for a number of reasons. most important is the immune system, which is needed to control the infection processes. this difference can lead to more serious infections than in adults, who have fully developed immune systems. there are a number of significant physiological and behavioral differences between adults and children that place children at a greater risk of exposure and a greater risk of serious in ...	2006	16676900
norwalk virus-specific binding to oyster digestive tissues.	the primary pathogens related to shellfish-borne gastroenteritis outbreaks are noroviruses. these viruses show persistence in oysters, which suggests an active mechanism of virus concentration. we investigated whether norwalk virus or viruslike particles bind specifically to oyster tissues after bioaccumulation or addition to tissue sections. since noroviruses attach to carbohydrates of the histo-blood group family, tests using immunohistochemical analysis were performed to evaluate specific bin ...	2006	16707048
norovirus outbreak in a pediatric oncology unit.	norovirus (nv) is an etiologic agent of outstanding importance that can cause severe epidemic gastroenteritis in day-care centers, schools, nursing homes, and hospitals. therefore nv requires foremost attention as a pathogen responsible for epidemics of gastroenteritis in immunocompromised inpatients. in this study, a nv outbreak in a pediatric oncology unit is described and the consequences for this high-risk population are discussed.	2006	16716968
virucidal activity of a quaternary ammonium compound disinfectant against feline calicivirus: a surrogate for norovirus.	norovirus, formerly known as norwalk virus, is an important cause of gastroenteritis outbreaks in hospitals, food services, schools, and cruise ships. infection control practices by using disinfectants to eliminate noroviruses from surfaces and environmental samples reduce the morbidity and spread of virus outbreaks. there are not many commercial disinfectants effective against norovirus. noroviruses cannot be cultivated in vitro. however, feline calicivirus can be used as a surrogate to determi ...	2006	16765204
c-terminal arginine cluster is essential for receptor binding of norovirus capsid protein.	noroviruses are the major viral pathogens of epidemic acute gastroenteritis affecting people worldwide. they have been found to recognize human histo-blood group antigens as receptors. the p domain of norovirus capsid protein was found to be responsible for binding to viral receptors, and the recombinant p protein forms p dimers and p particles in vitro. in this study, we demonstrate that a highly conserved arginine (r) cluster at the c terminus of the p domain is critical for receptor binding a ...	2006	16840313
stable expression of a norwalk virus rna replicon in a human hepatoma cell line.	norwalk virus (nv) is a prototype strain of the genus norovirus in the family caliciviridae. the human noroviruses have emerged as major agents of acute gastroenteritis in all age groups, but there are no vaccines or antiviral agents partly due to the absence of a cell culture system. we report the generation of cells expressing self-replicating nv rna (nv replicon) following transfection of nv rna bearing an engineered neomycin resistance gene into cell lines of human (huh-7) or hamster (bhk21) ...	2006	16843517