Publications

sequence analysis of srsv in fecal specimens from an epidemic of infantile gastroenteritis, october to december 1995, japan.	from october to december in 1995, an epidemic of infantile gastroenteritis occurred all over japan except in hokkaido and okinawa prefectures. the number of infected infants and young children was estimated to be over 5 million cases [editorial, iasr 1996]. the stool specimens from patients were examined for the presence of small round structured viruses (srsvs) by reverse transcription-polymerase chain reaction (rt-pcr) and nucleotide sequencing of parts of the rna-dependent rna polymerase regi ...	1997	9260683
mixed genogroup srsv infections among a party of canoeists exposed to contaminated recreational water.	samples of faeces collected from a party of canoeists involved in a gastroenteritis outbreak were examined by electron microscopy and rt-pcr for evidence of infection with srsvs. a broadly reactive primer pair was used to detect srsvs followed by application of genogroup-specific primers to srsv-positive specimens. exposure data were collected by means of a questionnaire. srsvs were detected in 1/4 specimens examined by em and 3/4 by rt-pcr. genogrouping, and sequencing of pcr products revealed ...	1997	9260692
outbreak of viral gastroenteritis due to a contaminated well. international consequences.	small round-structured viruses (srsvs) are known to cause viral gastroenteritis, but until now have not been confirmed in the implicated vehicle in outbreaks.	1997	9268277
an electron microscopical investigation of small round viruses in non-bacterial gastroenteritis.	small round viruses implied in non-bacterial gastroenteritis were observed by electron microscope in stool specimens collected from 1993 to 1996. the specimens relative to 1981 were re-examined. the identified viruses are astroviruses (n = 6), caliciviruses (n = 7), norwalk-like viruses (n = 34) and parvoviruses (n = 6). immunoelectron microscopy (iem) and solid-phase immunoelectron microscopy (spiem) were used in order to verify serological differences existing among norwalk-like viruses from d ...	1997	9270177
study of norwalk virus and mexico virus infections at ga-rankuwa hospital, ga-rankuwa, south africa.	small round-structured viruses (srsvs) or norwalk-like viruses have been implicated as an important causative agent of gastroenteritis outbreaks. we used the relatively newly developed recombinant enzyme immunoassays (eias) to determine the seroprevalence of norwalk virus (nv) and mexico virus (mxv) in a family-based cohort and an antenatal clinic cohort at ga-rankuwa hospital, ga-rankuwa, south africa. high prevalences (96 to 99%) of anti-nv and anti-mxv antibodies were detected in both cohorts ...	1997	9276420
virus transmission via food.	viruses are transmitted to humans via foods as a result of direct or indirect contamination of the foods with human faeces. viruses transmitted by a faecal-oral route are not strongly dependent on foods as vehicles of transmission, but viruses are important among agents of foodborne disease. vehicles are most often molluscs from contaminated waters, but many other foods are contaminated directly by infected persons. the viruses most often foodborne are the hepatitis a virus and the norwalk-like ...	1997	9282391
biochemical characterization of a smaller form of recombinant norwalk virus capsids assembled in insect cells.	the expression of the single capsid protein of norwalk virus (nv) in spodoptera frugiperda (sf9) insect cells infected with recombinant baculovirus results in the assembly of virus-like particles (vlps) of two sizes, the predominant 38-nm, or virion-size vlps, and smaller, 23-nm vlps. here we describe the purification and biochemical characterization of the 23-nm vlps. the 23-nm vlps were purified to 95% homogeneity from the medium of sf9 cultures by isopycnic cscl gradient centrifugation follow ...	1997	9311906
hospital outbreak of norwalk-like virus.	an outbreak of gastroenteritis caused by norwalk-like virus occurred in two areas of the hospital: area 1, consisting of three adjacent and interconnected wards, with mostly elderly patients; and area 22, an acute ward in a separate building with elderly patients. in area 1, 40 patients and 20 staff were affected; in area 2, 18 patients and 14 staff were affected. infection control measures were instituted in consultation with the government health authority. these measures did not appear to aff ...	1997	9324510
rt-pcr detection of rna viruses in stool specimens.		1997	9343674
waterborne outbreak of viral gastroenteritis.	a waterborne epidemic took place in a finnish municipality in april 1994. some 1500-3000 people, i.e. 25-50% of the population, had symptomatic acute gastroenteritis. laboratory findings confirmed adenovirus, a norwalk-like agent, small round viruses (srv), and group a and c rotaviruses as causative agents, norwalk virus being the main cause of the outbreak. the epidemic was most probably associated with contaminated drinking water. the groundwater well, situated in the embankment of a river, wa ...	1997	9360259
water-related disease in florida: continuing threats require vigilance.		1997	9360354
an outbreak of norwalk virus gastroenteritis following consumption of oysters.	in august 1996, an outbreak of norwalk virus gastroenteritis occurred among south-east queensland and northern new south wales residents over a four week period. ninety-two of the 97 cases detected were confirmed as having consumed raw oysters within three days prior to developing the illness. no other food items or beverages were significantly associated with the illness. environmental investigations indicated the terranora broadwater, tweed heads as the origin of the contaminated oysters. howe ...	1997	9375446
commentary. an outbreak of norwalk virus gastroenteritis following consumption of oysters.		1997	9375447
correlation of patient immune responses with genetically characterized small round-structured viruses involved in outbreaks of nonbacterial acute gastroenteritis in the united states, 1990 to 1995.	small round-structured viruses (srsvs) are a genetically and antigenically diverse group of caliciviruses that are the most common cause of outbreaks of acute nonbacterial gastroenteritis. we have applied both molecular techniques to characterize srsvs in fecal specimens and serologic assays using four different expressed srsv antigens to examine the distribution of outbreak strains in the united states and determine if the immune responses of patients were strain specific. strains from 23 outbr ...	1997	9407386
viral infections transmitted by food of animal origin: the present situation in the european union.	the goal of this presentation was to clarify which foods are involved in viral diseases, which viruses are transmitted via food and how to evaluate the risk of a foodborne viral infection. food items frequently identified as cause of viral disease outbreaks were shellfish harvested in sewage-contaminated water. another common source of foodborne viral illness was cold food contaminated by infected food handlers. in the european union the viruses most frequently associated with foodborne illness ...	1997	9413541
molecular characterization of morphologically typical human calicivirus sapporo.	human calicivirus sapporo (sv) has typical calicivirus morphology and causes acute gastroenteritis in children. the nucleotide sequence of 3.2 kb of the 3' end of sv was determined from a cloned cdna. the 3' end of the sv genome is predicted to encode the rna-dependent rna polymerase region, the capsid protein and two small open reading frames. the nonstructural and capsid protein coding sequences in the sv genome are fused in a single open reading frame. the organization of these proteins in th ...	1997	9672617
transgenic plants created for oral immunization against diarrheal diseases.	we have created transgenic plants that express subunit antigens of infectious bacteria and viruses. these proteins have been isolated and characterized to demonstrate that they retain immunogenic properties. when raw potatoes containing the recombinant immunogens were fed to mice, the animals were orally immunized. research completed to date has demonstrated the feasibility of using a genetically-engineered food as an inexpensive oral vaccine production and delivery system for diarrheal disease. ...	1996	9815423
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
[outbreak of food-borne gastroenteritis caused by a norwalk-like virus. evaluation of methods for confirmation of the etiology in suspected viral gastroenteritis].	acute gastroenteritis is a common disease and can be food-borne. we describe an outbreak of acute gastroenteritis, probably caused by norwalk-like virus, which struck 250 people in the course of one week in a small norwegian community. the source of the infection was probably an infected food handler in a bakery who contaminated cream cakes with the virus. the sensitivity of electronmicroscopy and analyses of igg antibodies in serum to detect the etiologic agent was very low. the sensitivity to ...	1996	9011988
[an outcome of water-borne gastroenteritis in klaebu].	in november 1994 a major outbreak of acute gastroenteritis was experienced in the municipality of klaebu (4,486 inhabitants). to investigate the course and extent of the epidemic, a questionnaire was mailed to all 1,573 households. the returned questionnaires covered 2,943 persons, of whom 1,640 (56%) were reported ill with the following most common symptoms: nausea (83%), vomiting (78%), diarrhoea (72%) and abdominal pain (70%). the epidemic curve was typical of a common source epidemic. the in ...	1996	9011996
viral gastroenteritis. introduction.		1996	9015096
overview of viral gastroenteritis.	diarrheal illnesses in humans have been recognized since antiquity. such illnesses continue to take a great toll of lives, with a disproportionately high mortality in infants and young children in developing countries. bacteriologic and parasitologic advances made during the past century led to the discovery of the etiology of some of the diarrheal illnesses, but the etiology of the major portion remained unknown. it was assumed that viruses caused most of these illnesses because: (i) bacteria w ...	1996	9015097
structure of norwalk virus.	norwalk virus is the major cause of epidemic viral gastroenteritis of humans. attempts to grow this 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. we have determined the 3-dimensional structure of baculovirus-expressed norwalk virus using electron cryomicroscopy and computer image reconstruction to a resolution of approximat ...	1996	9015120
recombinant norwalk virus-like particles as an oral vaccine.	viruses that infect cells in the gastrointestinal tract are well suited for examining the immune response to oral delivery of antigen and for exploring the advantages and pitfalls of oral vaccines. norwalk virus (nv) (family caliciviridae, genus calicivirus) causes acute gastroenteritis in all age groups. the nv capsid is composed of 180 copies of a single 58000 molecular weight protein which spontaneously forms virus-like particles (vlps) that can be purified in extremely high yields (22 mg per ...	1996	9015121
genetic and antigenic diversity of human caliciviruses (hucvs) using rt-pcr and new eias.	rt-pcr using primers from conserved regions of calicivirus genomes, followed by sequencing, permits characterization of genetic variation within the family. eias based on baculovirus-expressed viral capsid proteins and hyperimmune antisera against the capsid proteins were developed to detect hucv antigens and antibodies. serologic surveys using recombinant norwalk virus (rnv) and recombinant mexico virus (rmx, a sma-like virus) eias showed that infections by hucvs are common and that children ac ...	1996	9015122
the epidemiology of human calicivirus/sapporo/82/japan.	based on genome analysis of the rna-dependent rna polymerase region, it has been proposed that human caliciviruses (hucv) can be classified into at least three genogroups: genogroup i is represented by norwalk virus (nv), genogroup ii by snow mountain agent (sma) and genogroup iii by hucv/sapporo/82/japan (hucv/sa/82/j) virus. hucv/sa/82/j strain is genetically unique and more closely related to animal caliciviruses than are other known hucvs, such as nv and sma. hucv/sa/82/j strain was detected ...	1996	9015123
reverse transcription-polymerase chain reaction detection and sequence analysis of small round-structured viruses in japan.	between 1985 and 1995, mass outbreaks of acute gastroenteritis caused by small round-structured virus (srsv), occurred in eight prefectures in japan. fecal samples from 59 patients ill during these outbreaks were recently examined in our laboratory by electron microscopy (em) and by reverse transcription-polymerase chain reaction (rt-pcr). for rt-pcr, we prepared two sets of primers, a set corresponding to the polymerase region of open reading frame 1 (orf-1) and a set corresponding to the capsi ...	1996	9015124
new molecular methods for the detection of hepatitis a and norwalk viruses in shellfish.	outbreaks of viral enteric diseases after consumption of shellfish are a major health risk. methodological problems (such as toxicity for cell cultures and low viral concentrations) and the unculturability of some strains (i.e. hepatitis a virus, norwalk virus) have made it difficult to study those viruses in the environmental samples. currently, the analysis of the hygienic quality of marketable shellfish is determined by the use of fecal indicator bacteria, but their reliability in determining ...	1996	9018688
viral gastroenteritis: small round structured viruses, caliciviruses and astroviruses. part ii. the epidemiological perspective.		1996	9038729
collaborative evaluation of a method for the detection of norwalk virus in shellfish tissues by pcr.	a multicenter, collaborative trial was performed to evaluate the reliability and reproducibility of a previously described method for the detection of norwalk virus in shellfish tissues with the pcr (r.l. atmar, f. h. neill, j. l. romalde, f. le guyader, c. m. woodley, t. g. metcalf, and m. k. estes, appl. environ. microbiol. 61:3014-3018, 1995). virus was added to the stomachs and hepatopancreatic tissues of oysters or hard-shell clams in the control laboratory, the samples were shipped to the ...	1996	8572702
antigenic mapping of the recombinant norwalk virus capsid protein using monoclonal antibodies.	norwalk virus (nv) is the prototype strain of a group of noncultivatable caliciviruses that infect humans and cause outbreaks of epidemic acute nonbacterial gastroenteritis. the nv virion is composed of 180 copies of a single structural protein that, when expressed in insect cells infected with a recombinant baculovirus, assembles into empty recombinant norwalk virus-like particles (rnv vlps) which are morphologically and antigenically similar to native nv. we have begun to dissect the antigenic ...	1996	8599210
a university outbreak of gastroenteritis due to a small round-structured virus. application of molecular diagnostics to identify the etiologic agent and patterns of transmission.	an epidemiologic investigation of a gastroenteritis outbreak in december 1994 indicated that salad consumption during lunch was linked with illness on 2 days (5 december: odds ratio [or]=3.1, 95% confidence interval [ci]=2.0-5.0; 6 december: or=3.1, 95% ci=1.9-4.9). single stool or vomitus specimens from ill students and staff (case-patients) were examined for bacterial and viral pathogens. small round-structured viruses (srsvs) were detected by electron microscopy in stool specimens from 9 of 1 ...	1996	8603955
an epidemiological investigation of norwalk virus infection in south africa.	a study was carried out to determine the incidence and seroprevalence of norwalk virus (nv) in the pretoria area, south africa, using a recombinant nv (rnv) immunoassay for the detection of serum igg antibodies. maternal antibody was detectable in infants' sera up to approximately 6 months of age. infection with nv was detected serologically in the second year of life and the seroprevalence of nv igg rose from 37.1% at 7-11 months of age to 62.1% by the age of 40 years. no significant difference ...	1996	8620912
polyprotein processing in southampton virus: identification of 3c-like protease cleavage sites by in vitro mutagenesis.	a genomic clone of the small, round-structured virus southampton virus (sv) was constructed from a set of overlapping pcr amplicons. sequence analysis confirmed the absence of mutations and accurate ligation of the pcr products. the sv cdna was cloned into a vector for in vitro production of rna and subsequent translation by rabbit reticulocyte lysate. two polypeptides corresponding to the n-terminal and c-terminal regions of the viral polyprotein were expressed in escherichia coli and used to p ...	1996	8642693
expression of norwalk virus capsid protein in transgenic tobacco and potato and its oral immunogenicity in mice.	alternatives to cell culture systems for production of recombinant proteins could make very safe vaccines at a lower cost. we have used genetically engineered plants for expression of candidate vaccine antigens with the goal of using the edible plant organs for economical delivery of oral vaccines. transgenic tobacco and potato plants were created that express the capsid protein of norwalk virus, a calicivirus that causes epidemic acute gastroenteritis in humans. the capsid protein could be extr ...	1996	8643575
outbreaks of norwalk-like virus-associated gastroenteritis traced to shellfish: coexistence of two genotypes in one specimen.	we determined the nucleotide sequences of norwalk-like viruses in 10 pcr products from stool or oyster specimens obtained from four outbreaks of gastroenteritis in which shellfish was suspected as the cause in shizuoka prefecture in japan between 1987-94. the sequences were determined from nucleotide positions 4561-4852 (292 bp) in the polymerase region. two types of sequences were detected. one (genotype 1) had 87% sequence homology with the prototype norwalk virus, and the other (genotype 2) h ...	1996	8666079
detection and sequencing of norwalk-like viruses from stool samples in japan using reverse transcription-polymerase chain reaction amplification.	norwalk-like viruses were detected in japan in 12% (26/209) of patients with nonbacteria and nonrotavirus gastroenteritis in an outpatient clinic of a hospital from 1991 to 1994 by reverse transcription-polymerase chain reaction. they were also present in 7% (26/378) of total samples including those from rotavirus-positive gastroenteritis patients. in addition, the viruses were recovered in samples from 15 of 17 patients which were collected during outbreaks of gastroenteritis in various places ...	1996	8709869
molecular characterization of camberwell virus and sequence variation in orf3 of small round-structured (norwalk-like) viruses.	five small round-structured viruses (srsvs) associated with gastroenteritis in victoria, australia, from january to november 1994 were examined by sequencing cdna prepared from faecal samples using rt-pcr. the sequence of the 3' half (3.8 kb) of the genome of one of these viruses, camberwell, was determined. camberwell virus was related most closely to bristol and lordsdale viruses, and belonged to the genetic group of srsvs containing bristol, lordsdale, toronto, oth-25, mexico, and hawaii viru ...	1996	8732863
longitudinal study of molecular epidemiology of small round-structured viruses in a pediatric population.	small round-structured viruses (srsv), recently designated members of the family caliciviridae, can now be readily subtyped by amplification of a defined portion of their genome by reverse transcription-pcr and then by identification of the amplicons with specific probes by southern blotting. a longitudinal survey (from 1991 to 1995) was conducted to determine the genotypes of the srsv present in pediatric stool specimens from patients with sporadic cases of gastroenteritis. it was found that al ...	1996	8735105
molecular detection and epidemiology of small round-structured viruses in outbreaks of gastroenteritis in the netherlands.	to study the epidemiology of small round-structured viruses (srsv) in the netherlands, all outbreaks of gastroenteritis that were reported to the research laboratory for infectious diseases, department of virology, national institute of public health and the environment (rivm) in 1994 and 1995 were examined using electron microscopy (em), single-round reverse transcription-polymerase chain reaction (rt-pcr), and sequencing. to enable this, a generic srsv-specific primer pair was developed that c ...	1996	8769621
[outbreak of non-bacterial gastroenteritis in a school].	an outbreak of gastroenteritis occurred in a school affecting more than 30% of its 535 students. an epidemiological survey questionnaire was given to all students as well as staff and maintenance personnel. stool cultures and electronic microscopy were used to detect the presence of a norwalk-like virus. several analyses of water samples were also done. this outbreak occurred simultaneously in the two wings of the school (east and south). those who used the east wing were most affected by the di ...	1996	8771928
a virion concentration method for detection of human enteric viruses in oysters by pcr and oligoprobe hybridization.	this article reports the development of a method to purify and concentrate intact virions from oyster extracts to volume and quality compatible with viral genomic nucleic acid amplification by reverse transcriptase pcr (rt-pcr) and confirmation by oligonucleotide probe hybridization. fifty-gram oyster samples were processed by an adsorption-elution -precipitation method and then seeded with 10(1) to 10(5) pfu of poliovirus type 1 (pv1) or hepatitis a virus (hav). seeded viruses in oyster extract ...	1996	8787405
immunoaffinity concentration and purification of waterborne enteric viruses for detection by reverse transcriptase pcr.	to assess the risks from viral contamination of drinking-water supplies, there is a clear need for methods to directly detect viral pathogens. in this study, we developed a broad-spectrum immunocapture method for concentration and purification of enteric viruses. the method involved indirect antibody capture (abcap) of intact viruses followed by release of virion genomic rna and reverse transcriptase pcr for amplification and oligoprobe hybridization for detection. the procedure involved concent ...	1996	8787407
attachment and entry of recombinant norwalk virus capsids to cultured human and animal cell lines.	norwalk virus (nv) is the prototype strain of a group of noncultivable human caliciviruses responsible for epidemic outbreaks of acute gastroenteritis. while these viruses do not grow in tissue culture cells or animal models, expression of the capsid protein in insect cells results in the self-assembly of recombinant norwalk virus-like particles (rnv vlps) that are morphologically and antigenically similar to native nv. we have used these rnv vlps to examine virus-cell interactions. binding and ...	1996	8794293
prevalence of serum antibodies to norwalk virus among norwegian military recruits.	the prevalence of serum antibodies against norwalk virus among military recruits in norway was investigated using an enzyme-linked immunosorbent assay (elisa). a total of 1017 sera were assayed for anti-norwalk virus total antibodies (ig), of which 300 (29.5%) were positive. of 227 positive sera, 10.6 and 15.4% were positive for iga and igm, respectively, while 2.2% were positive for both. the prevalence of antibodies against norwalk virus in south-east norway was significantly higher than that ...	1996	8796425
comparison of four rna extraction methods for the detection of small round structured viruses in faecal specimens.	four methods for extraction of the rna genome of small round structured viruses (srsvs) from faecal specimens by reverse transcription polymerase chain reaction (rt-pcr) were evaluated. the efficiency of recovery of viral rna and removal of amplification inhibitors were compared. rna extraction using the metal chelating agent chelex-100 and sephadex g200 column chromatography were the most sensitive, detecting a 10(-4) dilution of a known srsv positive specimen. guanidinium thiocyanate (gtc) wit ...	1996	8801231
study on occurrence of human calicivirus (mexico strain) as cause of sporadic cases and outbreaks of calicivirus-associated diarrhoea in the united kingdom, 1983-1995.	the use of a recently developed eia using antisera raised against purified baculovirus expressed recombinant mexico virus (rmx) capsid protein is described for screening for human calicivirus in stools. the results show that mx-like viruses have been circulating in the uk periodically since 1983 and were an occasional cause of sporadic cases of diarrhoea in infants and outbreaks of infection among elderly patients in hospitals and old people's homes. further evidence is presented that some strai ...	1996	8801289
surveillance of outbreaks of small round structured virus infection.		1996	8851206
gastrointestinal manifestations of hiv infection.		1996	8855890
completion of the norwalk virus genome sequence.	norwalk virus (nv) is the prototype human calicivirus, and causes epidemic outbreaks of acute gastroenteritis. the sequence and predicted genome organization of nv and a nv-like virus [southampton virus (shv)] suggested they are similar viruses at the nucleotide and amino acid level, although shv was reported to be antigenically distinct from nv. a recent review described the discovery of an additional 12 nucleotides at the 5' end of shv and prompted us to investigate the possibility of addition ...	1996	8883366
an outbreak of norwalk-like virus infection in tokyo and saitama in late 1995.		1996	8890552
detection and analysis of a small round-structured virus strain in oysters implicated in an outbreak of acute gastroenteritis.	outbreaks of shellfish-transmitted viral disease occur periodically, but frequently the causative agent is not identified. in november 1993, during investigation of a multistate outbreak of acute gastroenteritis, incriminated lots of oysters were collected. oyster tissues (stomachs and digestive diverticula) were processed for virus extraction and nucleic acid purification. human calicivirus sequences were sought by reverse transcriptase pcr using different primer sets. amplicons were obtained f ...	1996	8900022
dot blot hybridization with a cdna probe derived from the human calicivirus sapporo 1982 strain.	a dot blot hybridization assay was developed for detection of human calicivirus/sapporo/82/j (hucv/sa/82) or strains closely related to hucv/sa/82 in stool specimens. the cdna derived from the rna-dependent rna polymerase (rdrp) region of hucv/sa/82 was used as a positive probe and the pbr322 dna as a negative control probe. both probes were labeled with digoxigenin and the products of hybridization reaction were detected with an anti-digoxigenin antibody-alkaline phosphatase conjugate. this ass ...	1996	8920827
viral gastroenteritis: small round structured viruses, caliciviruses and astroviruses. part i. the clinical and diagnostic perspective.		1996	8944604
outbreaks of gastroenteritis in elderly nursing homes and retirement facilities associated with human caliciviruses.	eleven outbreaks of acute gastroenteritis, eight of which were in nursing homes or retirement facilities, were reported in virginia during the winter of 1993-1994. serum samples (four outbreaks) and stool samples (two outbreaks) from involved people were tested for human calicivirus (hucv) infection by enzyme immune assays (eias) using recombinant norwalk virus (rnv) and mexico virus (rmx) capsid antigens and reverse transcription-polymerase chain reaction (rt-pcr). of the 31 pairs of acute and ...	1996	8950691
steaming oysters does not prevent norwalk-like gastroenteritis.	to determine whether steaming oysters prevents gastroenteritis caused by small round structured (norwalk-like) viruses and to identify risk factors for illness.	1996	8955700
[outbreak of non-bacterial gastroenteritis in a school].	an outbreak of gastroenteritis occurred in a school affecting more than 30% of its 535 students. an epidemiological survey questionnaire was given to all students as well as staff and maintenance personnel. stool cultures and electronic microscopy were used to detect the presence of a norwalk-like virus. several analyses of water samples were also done. this outbreak occurred simultaneously in the two wings of the school (east and south). those who used the east wing were most affected by the di ...	1996	8964025
evaluation of a degenerate primer for the pcr detection of human caliciviruses.	numerous outbreaks of gastroenteritis have been associated with norwalk virus and small round structured viruses (srsvs). these single-stranded rna viruses, recently classified in the caliciviridae, have been divided into three genogroups. antigenic relationships also have been established among the different strains. as both an in vitro culture system and an animal model are lacking for these viruses, virus detection depends primarily on electron microscopy, immunological assays or molecular de ...	1996	8973536
an outbreak of viral gastroenteritis on a cruise ship.	three hundred and seventy-eight passengers reported gastroenteritis during four cruises in the western mediterranean on consecutive weeks of 1995. the rate at which cases were reported each day increased on the fourth cruise. the ship's owner commissioned an epidemiological investigation from the phls communicable disease surveillance centre. cases reported explosive vomiting and diarrhoea, which lasted from 24 hours to five days, and were suggestive of viral gastroenteritis. no food handlers re ...	1996	8990576
medical microbiology	the caliciviruses are small, nonenveloped rna viruses that have characteristic cup-shaped depressions on a spherical capsid surface; hence their name, which is derived from calyx or chalice. caliciviruses have a distinctive structure, sometimes described as a star of david, and are also distinctive in their size (27 to 35 nm), in having only a single major polypeptide, and in the functions of the single-stranded rna genome. they produce mucocutaneous and respiratory tract lesions in several anim ...	1996	21413349
epidemiologic applications of novel molecular methods to detect and differentiate small round structured viruses (norwalk-like viruses).	the molecular epidemiology of a large, multistate outbreak of oyster-associated gastroenteritis [kohn et al. (1995): journal of the american medical association 273:466-471. dowell et al. (1995): journal of infectious diseases 171:1497-1503.] was examined using new methods to detect small round structured viruses (srsvs) by reverse transcription-polymerase chain reaction (rt-pcr) and to characterize strains by southern hybridization and nucleotide sequencing of 81-bp of a pcr product amplified f ...	1995	8830118
from the centers for disease control and prevention. multistate outbreak of viral gastroenteritis associated with consumption of oysters--apalachicola bay, florida, december 1994-january 1995.		1995	7837350
an outbreak of norwalk virus gastroenteritis associated with eating raw oysters. implications for maintaining safe oyster beds.	to determine the characteristics and the cause of an outbreak of gastroenteritis associated with eating raw oysters.	1995	7837364
capsid diversity in small round-structured viruses: molecular characterization of an antigenically distinct human enteric calicivirus.	studies of antigenic variation between small round-structured viruses (srsvs) using immune electron microscopy have revealed 3 antigenic types currently circulating in the uk represented by the strains srsv/bri/93/uk, srsv/sot/91/uk and srsv/mel/89/uk. mel/89/uk rna was isolated from a 1989 school outbreak of gastroenteritis. the 3'-terminal 3435 nucleotides (excluding the poly(a) tail) were determined by rt-pcr and cdna sequencing, completing our molecular characterization of antigenically dive ...	1995	8533462
detection of small round structured viruses in shellfish by reverse transcription-pcr.	we describe the application of a previously developed sample extraction procedure to the detection of small round structured viruses (srsvs) in shellfish. initial seeding experiments showed that pcr inhibitor removal and virus recoveries were comparable to those in previous studies with poliovirus. shellfish from a range of sewage-contaminated sites were then tested for the presence of srsvs by using broadly reactive pcr primers followed by southern blotting with internal probe sites. positive r ...	1995	8534105
outbreaks of gastroenteritis due to norwalk-like virus in two long-term care facilities for the elderly.	in february 1993, outbreaks of gastroenteritis due to norwalk-like viruses occurred simultaneously among the elderly residents of two long-term care facilities. facility a instituted infection control measures that included increased surveillance, reinforcement of handwashing, keeping symptomatic residents in their rooms and relieving symptomatic staff of their work duties until 48 h after resolution of their symptoms. facility b instituted a more stringent set of control measures that included ...	1995	8547682
antibody prevalence and immunoglobulin igg subclass pattern to norwalk virus in sweden.	the antibody prevalence in sweden to norwalk virus (nv) was investigated using a baculovirus expressed capsid antigen. one hundred thirty-two serum samples were examined for iga, total igg and igg subclass antibodies to norwalk virus. in young children, nv igg antibody prevalence was higher than the iga prevalence, whereas no difference was found in individuals older than 21 years. the igg antibody prevalence was 50% in children below 5 years of age and increased to > 80% in individuals older th ...	1995	8551259
isolation of cytopathic small round virus (aichi virus) from pakistani children and japanese travelers from southeast asia.	aichi virus was isolated in vero cells from 5 (2.3%) of 222 pakistani children with gastroenteritis but none was found in 91 healthy children. aichi virus was also isolated from 5 (0.7%) of 722 japanese travelers returned from tours to southeast asian countries and complained of gastrointestinal symptoms at the quarantine station of nagoya international airport in japan. of 5 japanese travelers, 3 were returning from indonesia, and 2 from thailand or malaysia. these results indicate that aichi v ...	1995	8551977
infection control. when winter makes you sick.		1995	8552486
a conserved sequence motif at the 5' terminus of the southampton virus genome is characteristic of the caliciviridae.	we have determined the 5'terminal cdna sequence for the genome of southampton virus, a recently characterized, human, small round-structured virus (srsv). genomic rna was extracted directly from a stool sample and amplified by rt-pcr by homopolymer tailing of the 3' terminus of the cdna. the additional sequence increases the overall length of the southampton virus genome by 12 nucleotides, resulting in a significant change to the genome organization by extending the first large open reading fram ...	1995	8560774
study of norwalk-related viruses in mexican children.	two-hundred mexican children monitored from birth to 2 years of age in a cohort study of diarrhea were tested for norwalk virus (nv) and norwalk-related virus infection. blood was collected quarterly and tested by an enzyme immunoassay (eia) using the recombinant nv (rnv) particles as antigen. stool was collected weekly and tested by an eia using hyperimmune anti-sera from animals immunized with rnv and a reverse transcription-polymerase chain reaction (rt-pcr) with primers in the rna polymerase ...	1995	8636696
molecular characterisation of small round structured viruses associated with gastroenteritis in south africa.	the application of the reverse transcriptase polymerase chain reaction (rt-pcr) has enabled several morphologically and physically similar small round structured viruses (srsvs), including the prototype norwalk virus (nv), to be classified within the caliciviridae. this technique, using primers directed to the rna-dependent rna polymerase region within the orf1 of nv, was used to characterise srsvs associated with epidemic gastroenteritis in adults and sporadic paediatric gastroenteritis in sout ...	1995	8636707
broadly reactive reverse transcriptase polymerase chain reaction for the diagnosis of srsv-associated gastroenteritis.	a limitation to date of reverse transcriptase polymerase chain reactions (rt-pcrs) for the detection of small, round structured viruses (srsvs) has been that they have detected only a narrow range of srsvs due to the marked genomic diversity among strains. a total of 331 faecal samples collected from 136 separate incidents of gastroenteritis occurring in the uk between 1992 and 1994 were examined by rt-pcr employing a single primer pair (n1/e3). srsv rna was detected in samples from 93 of 101 (9 ...	1995	8636708
small round structured viruses (srsv): numbers are increasing.		1995	7620522
bacillus cereus and bacillus thuringiensis isolated in a gastroenteritis outbreak investigation.	during investigation of a gastroenteritis outbreak in a chronic care institution, norwalk virus was found in stool specimens from two individuals and bacterial isolates presumptively identified as bacillus cereus were isolated from four individuals (including one with norwalk virus) and spice. phage typing confirmed all bacillus clinical isolates were phage type 2. all clinical isolates were subsequently identified as b. thuringiensis when tested as a result of a related study (l. leroux, person ...	1995	7639990
an outbreak of viral gastroenteritis associated with adequately prepared oysters.	over christmas 1993, an outbreak of food poisoning occurred among guests in a hotel in south west scotland. evidence from a cohort study strongly suggested that raw oysters were the vehicle for infection, probably due to a small round structured virus (srsv). detailed enquiry about the source and preparation of the oysters revealed no evidence of any unsafe handling at any stage in the food chain, nor any evidence of bacterial contamination. it is suggested that the present standards of preparat ...	1995	7641830
expression, self-assembly, and antigenicity of a snow mountain agent-like calicivirus capsid protein.	virus-like particles were produced in insect cells infected with a recombinant baculovirus containing the capsid gene of mx virus, a mexican strain of human calicivirus. these recombinant mx (rmx) particles were morphologically similar to recombinant norwalk virus (rnv) particles as observed under an electron microscope and contained a single capsid protein with a molecular weight of 57,000, which was slightly smaller than that of rnv. this protein was immunoprecipitated by sera from volunteers ...	1995	7650166
human enteric caliciviruses have a unique genome structure and are distinct from the norwalk-like viruses.	classic human enteric caliciviruses (hucvs) have a distinctive morphology and are primarily associated with pediatric acute gastroenteritis. although morphologically distinct from the small round structured viruses (srsvs), the classic hucvs are thought to be closely related and were anticipated to have a similar genome organisation. we report the first genome sequence and molecular characterisation of a classic human enteric calicivirus associated with a case of acute vomiting and diarrhoea in ...	1995	7661689
detection and differentiation of antigenically distinct small round-structured viruses (norwalk-like viruses) by reverse transcription-pcr and southern hybridization.	application of reverse transcription (rt)-pcr to detect small round-structured viruses (srsvs) from fecal specimens of patients with gastroenteritis has been insensitive because of the tremendous sequence heterogeneity between strains. we have designed two rt-pcr primer sets (g-1 and g-2) based on the nucleotide sequence diversity in the rna polymerase gene of srsvs belonging to two distinct genogroups represented by norwalk virus (primers g-1) and snow mountain agent (primers g-2). all 22 srsv ...	1995	7699068
characterization of srsvs using rt-pcr and a new antigen elisa.	stool samples from 451 patients involved in volunteer studies, 26 outbreaks and approximately 175 sporadic cases of acute gastroenteritis from different geographical locations in the world were tested for norwalk virus (nv) using a newly developed antigen elisa and rt-pcr. nv was detected in most outbreaks previously characterized as being of nv origin. overall, a low number of positives for nv was obtained using either rt-pcr with primers that amplified a unique region of the genome, or an elis ...	1995	7710362
use of solid-phase immune electron microscopy for classification of norwalk-like viruses into six antigenic groups from 10 outbreaks of gastroenteritis in the united states.	norwalk-like viruses observed in fecal specimens from 10 outbreaks of gastroenteritis investigated in the united states between 1987 and 1992 were analyzed by solid-phase immune electron microscopy. outbreak virus strains were classified into six antigenic groups: the four types (uk1 to uk4) previously defined in the united kingdom, norwalk virus, and the oklahoma agent that was newly defined in this study. the diversity of antigenic types demonstrated in these outbreaks was greater than previou ...	1995	7714218
epidemiology of norwalk virus during an outbreak of acute gastroenteritis aboard a us aircraft carrier.	a large outbreak of acute gastroenteritis occurred over a 5-week period aboard an aircraft carrier. the estimated cumulative attack rate was 13% among the 4,500-man crew. eight percent of the crew sought medical attention, nearly all of whom missed 1 day or more of work. the risk of developing illness was 2 to 3 times greater for individuals living in more crowded sleeping quarters (> 50 persons per compartment). occurrence of gastroenteritis was associated with a fourfold or more rise in norwal ...	1995	7714493
molecular characterization of a human calicivirus with sequence relationships closer to animal caliciviruses than other known human caliciviruses.	cdna clones were produced from a morphologically typical human calicivirus (hucv) in stool specimens collected in 1982 during an outbreak of gastroenteritis in sapporo, japan. the cdna clones were generated separately in two laboratories by reverse transcriptase-polymerase chain reaction (rt-pcr) using primers 35 and 36 derived from norwalk virus. the rt-pcr product from six specimens was of the predicted size, had a continuous protein encoding frame on the positive strand, and contained glps an ...	1995	7775942
multistate outbreak of viral gastroenteritis associated with consumption of oysters--apalachicola bay, florida, december 1994-january 1995.	on january 3, 1995, the florida department of health and rehabilitative services (hrs) was notified of an outbreak of acute gastroenteritis associated with eating oysters. the subsequent investigation by hrs has identified 34 separate clusters of cases, many of which were associated with oysters harvested during december 29-31 from 13 mile area and cat point in apalachicola bay. oysters were shipped to other states, but additional clusters of illness associated with these oysters have been repor ...	1995	7808387
specific proteolytic cleavage of recombinant norwalk virus capsid protein.	norwalk virus (nv) causes epidemic outbreaks of acute nonbacterial gastroenteritis in humans. the nv capsid is made up of a single protein, and expression of the capsid protein in baculovirus recombinants results in spontaneous assembly of the protein into virus-like particles (x. jiang, m. wang, d. y. graham, and m. k. estes, j. virol. 66:6527-6532, 1992). we have investigated whether the nv capsid protein undergoes a specific proteolytic cleavage. recombinant nv (rnv) particles were digested w ...	1995	7853506
diarrheal disease among military personnel during operation restore hope, somalia, 1992-1993.	the potential for widespread diarrheal disease was regarded as a substantial threat to u.s. troops participating in the early phases of operation restore hope in somalia. outpatient surveillance of 20,859 u.s. troops deployed during the first eight weeks, however, indicated that a mean of only 0.8% (range 0.5-1.2%) of personnel sought care for diarrhea each week, and in three epidemiologic surveys, < 3% of troops reported experiencing a diarrheal illness per week. despite these low overall attac ...	1995	7872452
viral shedding and fecal iga response after norwalk virus infection.	protection is not conferred by preexposure to norwalk virus (nv). by use of an elisa with baculovirus-expressed recombinant nv (rnv) capsid protein, the pattern of nv fecal shedding and the protective effect of rnv-specific fecal iga (flga) were investigated in volunteers who were repeatedly challenged with nv. after the first challenge, ill volunteers were significantly more likely than well volunteers to have nv antigen in their stool (p < .05). after challenge, antigen shedding was detected o ...	1995	7876602
detection of norwalk virus and hepatitis a virus in shellfish tissues with the pcr.	a method for the detection of norwalk virus and hepatitis a virus from shellfish tissues by pcr was developed. virus was added to the stomach and hepatopancreatic tissues of oysters or hard-shell clams, and viral nucleic acids were purified by a modification of a previously described method (r.l. atmar, t.g. metcalf, f.h. neill, and m.k. estes, appl. environ. microbiol. 59:631-635, 1993). the new method had the following advantages compared with the previously described method: (i) more rapid sa ...	1995	7487032
monoclonal antibodies for detection of norwalk virus antigen in stools.	monoclonal antibodies against the prototype 8fiia strain of norwalk virus were prepared and applied to an enzyme immunoassay (eia) for detecting norwalk virus in stool specimens. the monoclonal antibodies immunoprecipitated a 58-kda protein which had been produced by in vitro transcription-translation of norwalk virus cloned cdna, and they reacted by eia with recombinant norwalk virus capsid protein at a sensitivity level of 1 ng/ml. the eia detected virus in all tested samples from 15 different ...	1995	7494063
[gastroenteritis outbreak associated with water consumption, possibly caused by norwalk or norwalk-like virus].	it is described an acute gastroenteritis outbreak of probable hydric transmission in ontinyent (valencia). it was declared on the 31st of january, 1992 and affected 3541 people according to the declaration done by the sanitary services who attended the patients. the clinical situation was characterized by the presence of profuse and watery diarrhoea, nausea, vomiting, abdominal pain and fever or febricula.	1995	7497350
hyperemesis hiemis--a sick hazard.	epidemic non-bacterial gastroenteritis or winter vomiting disease is a well recognized clinical syndrome causing significant morbidity in the general population and in semi-closed communities. the norwalk group of viruses has become established as the aetiological agents responsible for this important clinical syndrome. as a result of their historically poorly-defined taxonomic status they have been alternatively described as small round structured viruses (srsvs) which allow their differentiati ...	1995	7560989
human enteric caliciviridae: the complete genome sequence and expression of virus-like particles from a genetic group ii small round structured virus.	comparisons of the rna polymerase and capsid sequences of small round structured viruses (srsvs) have recently shown these are genetically diverse viruses which fall into two distinct groups. the genomes of two group i viruses, southampton and norwalk viruses have been characterized; however, similar data for the genetic group ii srsvs have not been available until now. we report here the complete genome sequence of a recent group ii srsv, lordsdale virus. the lordsdale virus genome is 7555 nt i ...	1995	7561776
enzyme immunoassay using baculovirus-expressed human calicivirus (mexico) for the measurement of igg responses and determining its seroprevalence in london, uk.	the use of an enzyme immunoassay (eia) employing a baculovirus-expressed recombinant human calicivirus (mexico virus, mxv) for the detection of igg-specific antibodies is described. mxv appeared to be related antigenically to a strain of small round structured virus, srsv/uk4/leeds/91, which had previously been shown by solid phase immune electron microscopy (spiem) to be related to snow mountain agent (sma). one other outbreak which occurred in san anita, usa in 1980 and was due to consumption ...	1995	7561789
concentration and purification of beef extract mock eluates from water samples for the detection of enteroviruses, hepatitis a virus, and norwalk virus by reverse transcription-pcr.	in this study we developed a concentration and purification procedure to facilitate reverse transcription (rt)-pcr detection of enteric viruses in water sample concentrates obtained by conventional filter adsorption-elution methods. one liter of beef extract-glycine eluate with or without humic acid and seeded with poliovirus type 1, hepatitis a virus, and norwalk virus was used as a model system, and the eluent was further processed for rt-pcr compatibility. the sample concentration and purific ...	1995	7574592
a serosurvey of water-borne pathogens amongst canoeists in south africa.	certain health risks have been associated with recreational exposure to faecally polluted water. canoeing in certain south african waters is considered to be a high risk activity with regard to schistosomiasis, gastroenteritis and possibly hepatitis. in a cross-sectional study, a serosurvey was conducted amongst canoeists to ascertain whether or not they had a higher seroprevalence to hepatitis a virus, norwalk virus and schistosoma spp. than non-canoeists. in comparisons between the two groups, ...	1995	7589269
development of an elisa to detect mx virus, a human calicivirus in the snow mountain agent genogroup.	mx virus is a snow mountain agent (sma) genogroup human calicivirus (hucv) identified in a mexican child with diarrhoea. an elisa using hyperimmune antisera to the recombinant mx virus (rmx) capsid was developed to detect sma genogroup hucvs in stool specimens. the rmx elisa detected the prototype mx virus, sma, and hawaii agent (ha), but not norwalk virus (nv) or sapporo virus. twenty-three diarrhoea stool specimens from children attending day care centres in norfolk, virginia, were positive by ...	1995	7595381
gastroenteritis associated with oysters.		1994	7514927
comparison of the polymerase region of small round structured virus strains previously classified in three antigenic types by solid-phase immune electron microscopy.	we have used a reverse transcription-polymerase chain reaction with nested sets of primers to determine the nucleotide sequences of a 166 base pair segment of the rna polymerase region of seven strains of small round structured viruses (srsvs) from the united kingdom. these srsv strains were previously classified by solid-phase immune electron microscopy into three antigenic types--uk2, uk3 and uk4, which are comparable to the prototype strains norwalk virus, hawaii agent, and snow mountain agen ...	1994	7515226
development of a method for detection of enteroviruses in shellfish by pcr with poliovirus as a model.	the application of the pcr to complex samples is hindered by amplification inhibitors. we describe a reverse transcription-pcr-based method capable of inhibitor removal for the detection of enteroviruses in shellfish. initial virus extraction stages based on a modified polyethylene glycol precipitation technique (g.d. lewis and t.g. metcalf, appl. environ. microbiol. 54:1983-1988, 1988) were followed by virus purification with 1,1,2-trichloro,2,2,1-trifluoroethane and concentration by ultrafiltr ...	1994	7521997