| 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 |
| 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 |
| 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 |
| 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 |
| failure of cooking to prevent shellfish-associated viral gastroenteritis. | in january 1995, florida experienced the largest outbreak of oyster-associated gastroenteritis ever reported. | 1997 | 8996048 |
| use of heat release and an internal rna standard control in reverse transcription-pcr detection of norwalk virus from stool samples. | norwalk virus (nv) and the norwalk-like viruses are important human pathogens that cause epidemic acute viral gastroenteritis. current techniques used to recover nv from clinical samples involve multistep viral extraction and elution procedures with subsequent viral detection by reverse transcription-pcr (rt-pcr). in this study, a simple method using heat to recover viral rna from 45 stool samples was compared to a conventional viral rna extraction technique, with subsequent analysis by rt-pcr. ... | 1997 | 9003630 |
| [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 |
| prevalence of antibodies to human caliciviruses (hucvs) in kuwait established by elisa using baculovirus-expressed capsid antigens representing two genogroups of hucvs. | baculovirus recombinant-expressed antigens of norwalk viruses (rnv) and a mexico strain (rmx) of the snow mountain serogroup of human caliciviruses (hucvs) were used in enzyme immunoassays to study the antibody prevalence among the kuwaiti population and foreign workers employed in kuwait. the antibody titers in 16 different age groups which ranged from neonates to centenarians were investigated by testing eight different dilutions of each serum (1:200-1:25,600). the results indicate that nv inf ... | 1997 | 9021541 |
| viral gastroenteritis: small round structured viruses, caliciviruses and astroviruses. part ii. the epidemiological perspective. | | 1996 | 9038729 |
| a one-tube method of reverse transcription-pcr to efficiently amplify a 3-kilobase region from the rna polymerase gene to the poly(a) tail of small round-structured viruses (norwalk-like viruses). | amplification of a 3-kb genome region from the rna polymerase gene to the 3' poly(a) tail of small round-structured virus (srsv) by reverse transcription-pcr (rt-pcr) has been difficult to achieve because of a stable secondary structure in a region between the rna polymerase gene and the 5' end of the second open reading frame. we have developed a one-tube rt-pcr method to efficiently amplify this region. the method comprises three procedures: purification of poly(a)+ rna from a starting rna sol ... | 1997 | 9041391 |
| norwalk-like virus associated with gastroenteritis in babies. | | 1997 | 9076274 |
| incidence of human calicivirus and rotavirus infection in patients with gastroenteritis in south africa. | human caliciviruses (hucvs) are reportedly responsible for 2.5-4% of nonbacterial sporadic gastroenteritis. the incidence of hucv infection in south africa is unknown. stool specimens from 1,296 south african patients with sporadic gastroenteritis were screened for the presence of hucvs using electron microscopy, recombinant enzyme immunoassays for norwalk (nv) and mexican (mx) viruses, and the reverse transcriptase-polymerase chain reaction (rt-pcr). rt-pcr products were sequenced to ascertain ... | 1997 | 9093943 |
| capsid sequence diversity in small round structured viruses from recent uk outbreaks of gastroenteritis. | genetic typing of small round structured viruses (srsvs) by reverse transcription-polymerase chain reaction (rt-pcr) and sequencing has been confined to analysis of the rna polymerase because of the considerable genome variability outside of this region. to provide capsid sequence data for epidemiological studies and outbreak investigations, a broadly reactive capsid pcr was developed using two sets of degenerate, inosine-containing primers. primer pairs capla/caplb and caplla/capllb specificall ... | 1997 | 9131452 |
| possible prolonged environmental survival of small round structured viruses. | | 1997 | 9152829 |
| [acute gastroenteritis caused by small round viruses]. | | 1997 | 9153863 |
| virus-like particle vaccines for mucosal immunization. | viruses which infect the gastrointestinal tract are well suited for examining the immune response(s) to oral delivery of antigen and exploring the advantages and pitfalls of oral vaccines. we have used recombinant dna techniques to produce nonreplicating self-assembled virus-like particles (vlps) from two gastrointestinal viruses, rotavirus and norwalk virus. both of these viruses normally cause acute gastroenteritis in man or animals. the vlps are morphologically and antigenically similar to th ... | 1997 | 9192045 |
| expression and self-assembly of recombinant capsid protein from the antigenically distinct hawaii human calicivirus. | the norwalk and hawaii viruses are antigenically distinct members of the family caliciviridae and are considered to be important etiologic agents of epidemic gastroenteritis, with most studies focusing on the role of norwalk virus. to further investigate the importance of hawaii virus, hawaii virus-like particles (vlps) were produced by expression of its capsid protein in the baculovirus system and these vlps were used as the antigen in an enzyme-linked immunosorbent assay that was efficient in ... | 1997 | 9196224 |
| outbreak of small round structured virus gastroenteritis arose after kitchen assistant vomited. | a wedding reception at a north yorkshire hotel was followed by an explosive outbreak of gastroenteritis. the attack rate among the 111 guests was 50% and vomiting was a predominant feature. the results of laboratory and epidemiological investigations were consistent with a common source outbreak of small round structured virus (srsv) infection genotype ii. the source of the outbreak was traced to a kitchen assistant who suddenly became ill on the eve of the reception and vomited into a sink used ... | 1997 | 9219424 |
| 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 |
| oral immunization with recombinant norwalk virus-like particles induces a systemic and mucosal immune response in mice. | recombinant norwalk virus-like particles (rnv vlps) produced in insect cells were evaluated as an oral immunogen in cd1 and balb/c mice by monitoring rnv-specific serum total and subclass immunoglobulin g (igg) and intestinal iga responses. dose and kinetics of response were evaluated in the presence and absence of the mucosal adjuvant cholera toxin (ct). rnv-specific serum igg and intestinal iga were detected in the absence of ct, and the number of responders was not significantly different fro ... | 1998 | 9445035 |
| prevalence of antibodies to the hawaii strain of human calicivirus as measured by a recombinant protein based immunoassay. | the evaluation of an enzyme immunoassay using recombinant hawaii virus-like particles (rhv-lps) with a panel of sera which had been screened previously for antibodies to norwalk virus (nv) and mexico virus (mxv) is described. the assay was also applied to study the epidemiology of hawaii virus. adult volunteers challenged with the prototype (genogroup ii, human calicivirus) hv developed significant igg responses (16-32 fold rises) following challenge whereas adults challenged or naturally infect ... | 1998 | 9496372 |
| the role of seafood in foodborne diseases in the united states of america. | in the united states of america, seafood ranked third on the list of products which caused foodborne disease between 1983 and 1992. outbreaks connected with fish vectors were caused by scombroid, ciguatoxin, bacteria and unknown agents; in shellfish, unknown agents, paralytic shellfish poisoning, vibrio spp. and other bacteria, followed by hepatitis a virus, were responsible for the outbreaks. at least ten genera of bacterial pathogens have been implicated in seafood-borne diseases. over the pas ... | 1997 | 9501377 |
| detection of norwalk virus and other genogroup 1 human caliciviruses by a monoclonal antibody, recombinant-antigen-based immunoglobulin m capture enzyme immunoassay. | sera obtained from two groups of adult volunteers infected with norwalk virus (nv) and two groups of patients involved in two natural outbreaks were tested for nv-reactive immunoglobulin m (igm) by use of a monoclonal antibody, recombinant-antigen-based igm capture enzyme immunoassay (eia). no nv-reactive igm was detected in the preinoculation sera of 15 volunteers, and 14 of 15 showed nv-reactive antibodies postinfection with nv. all of the volunteers showed igg seroconversion to nv. in the out ... | 1998 | 9542938 |
| a viral gastroenteritis outbreak associated with person-to-person spread among hospital staff. | to identify the etiologic agent and risk factors associated with a hospital ward outbreak of gastroenteritis. | 1998 | 9552183 |
| homotypic and heterotypic igg and igm antibody responses in adults infected with small round structured viruses. | antibody responses to recombinant norwalk (rnv) and mexico (rmxv) viral capsid proteins were studied in 39 adults involved in outbreaks of gastroenteritis associated with genogroup 2 small round structured viruses (srsvs). nineteen individuals were involved in outbreaks associated with mxv-like strains and 20 in outbreaks associated with four other genogroup 2 srsvs. igg antibodies were measured in acute and convalescent sera using indirect enzyme-linked immunosorbent assay (elisa), and igm was ... | 1998 | 9557297 |
| an outbreak of viral gastroenteritis on board a cruise liner. | | 1998 | 9604521 |
| the role of environmental contamination with small round structured viruses in a hospital outbreak investigated by reverse-transcriptase polymerase chain reaction assay. | in may 1994 an outbreak of vomiting and diarrhoea occurred in a 28-bed long-stay ward for the mentally infirm. the predominant symptoms were vomiting, diarrhoea, malaise and abdominal pain lasting for approximately 12 h in most cases. the attack rate was 62% (13/21) for patients and 46% (16/35) for staff members. infection control measures were implemented (containment of infectious individuals, hand hygiene among staff and environmental decontamination) and the ward was closed to admissions. af ... | 1998 | 9617683 |
| norwalk virus infection in venezuela. | the presence of antibodies against norwalk virus (nv) was studied in sera from different venezuelan populations, using an enzyme immuno-assay (eia) based on recombinant nv protein. antibodies to nv were found in 47%-53% of urban subjects from caracas, 83% of rural subjects from the west of the country, and 73%-93% of amerindian subjects. the prevalences found in the rural and amerindian groups were significantly higher than that in the urban group. although about 50% of the children studied were ... | 1998 | 9625917 |
| prevalence of enteric viruses in human immunodeficiency virus seropositive patients in venezuela. | the prevalence of enteric viruses associated with gastroenteritis was determined in 125 stool samples from patients infected with the human immunodeficiency virus (hiv), with or without diarrhea. diagnostic assays included enzyme immunoassays for the identification of rotavirus, adenovirus, and norwalk virus; polyacrylamide gel electrophoresis for atypical rotaviruses and picobirnaviruses and polymerase chain reaction for astrovirus. enteric viruses were detected in 6.4% (8 of 125) of the stools ... | 1998 | 9661837 |
| small round-structured (norwalk-like) viruses and classical human caliciviruses in southeastern australia, 1980-1996. | a total of 6,226 fecal samples collected from 1980 to 1996 in the australian states of victoria, new south wales, and tasmania from individuals with gastroenteritis were tested for small round-structured viruses (srsvs) and classical human caliciviruses (clhucvs) by electron microscopy. there were 223 samples positive for srsvs, and nine positive for clhucvs. srsvs were detected in individuals of all ages and were commonly associated with gastroenteritis outbreaks in nursing homes and hospitals. ... | 1998 | 9661841 |
| 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 |
| detection of norwalk-like virus genes in the caecum contents of pigs. | norwalk-like virus genes were detected by rt-pcr in the caecum contents of pigs. positive pcr products were produced from four out of 1,117 samples by nested pcr using human srsv primers. nucleotide sequences between 4,561 and 4,852 numbered according to the norwalk virus genomic rna in the rna polymerase region were determined. between the norwalk virus sequence and the sequences detected in pigs, there was 58.2% to 59.9% sequence homology. the swine sequences were located on genogroup ii of hu ... | 1998 | 9687878 |
| application of rt-pcr designed from the sequence of the local srsv strain to the screening in viral gastroenteritis outbreaks. | the yuri strain of small round structured virus (srsv) was cloned from a fecal specimen in which virus particles were observed by electron microscopy. the most common rt-pcr protocol in japan, however, using 35/36 and nv81/nv82/sm82 nested primer pairs, could not detect the srsv genome in this specimen. nucleotide and amino acid sequence analysis revealed that the yuri strain is genetically close to the genotype ii of srsv. a novel procedure using primer sets designed from the nucleotide sequenc ... | 1998 | 9688078 |
| epidemiological study of prevalence of genogroup ii human calicivirus (mexico virus) infections in japan and southeast asia as determined by enzyme-linked immunosorbent assays. | mexico virus (mxv) is a genogroup ii human calicivirus (hucv). we conducted an epidemiological study to determine the prevalence of mxv infection in infants and adults in japan and southeast asia by enzyme-linked immunosorbent assays (elisas) developed by using baculovirus-expressed recombinant mxv (rmxv) capsids. of 155 stool specimens obtained from children younger than 10 years old with acute clinical gastroenteritis (diarrhea and vomiting) associated with small, round-structured viruses in j ... | 1998 | 9705378 |
| virion concentration method for the detection of human enteric viruses in extracts of hard-shelled clams. | a method to extract and concentrate intact human enteric viruses from oyster extracts for detection using reverse transcription-polymerase chain reaction (rt-pcr) was applied to hard-shelled clams (mercenaria mercenaria). fifty-gram clam samples were processed by an adsorption-elution-precipitation method and then seeded with 10(1) to 10(5) pfu to poliovirus 1 (pv1) and/or hepatitis a virus (hav). seeded viruses in extracts were purified by fluorocarbon (freon) extraction and concentrated by pol ... | 1998 | 9709210 |
| antigenic structure of the capsid protein of rabbit haemorrhagic disease virus. | rabbit haemorrhagic disease virus (rhdv) causes an important disease in rabbits. the virus capsid is composed of a single 60 kda protein. the capsid protein gene was cloned in escherichia coli using the pet3 system, and the antigenic structure of rhdv vp60 was dissected using 11 monoclonal antibodies (mabs) and 12 overlapping fragments of the protein expressed in e. coli. two antigenic regions were found. ten out of the 11 mabs recognized different discontinuous epitopes in the most immunodomina ... | 1998 | 9714238 |
| an outbreak of viral gastroenteritis associated with eating raw oysters. | nine members of a party of 24 people who attended a birthday party fell ill with gastroenteritis between one and three days later. a cohort study undertaken using a postal questionnaire showed that illness was associated with having eaten raw oysters. six of the cases had their stools examined and two were positive for small round structured virus. the illness was brief and none of the cases had consulted a general practitioner. had the cases not been part of a party they would not have been ide ... | 1998 | 9718837 |
| the use of reverse transcriptase-polymerase chain reaction to investigate environmental samples for the presence of enteroviruses. | molecular techniques developed for detection and diagnosis of enteric viruses have been adapted for use with water samples. although problems of interference and sensitivity remain, reliable and consistent methods should soon be available for the detection in water of enteroviruses, norwalk-like viruses, and rotavirus. | 1998 | 9718844 |
| [viral contamination of food products: a poorly understood public health problem]. | throughout the world there have been several epidemics of food-borne diseases (fbd) about which there is lack of sufficient information for public health institutions to take appropriate measures. this study was conducted for the purpose of contributing to the dissemination of information on these diseases and their etiologic agents, epidemiology, and control. the study was based on data from 61 sources, including review articles, reports of outbreaks, and databases. results reveal considerable ... | 1998 | 9734216 |
| surveillance of small round structured virus (srsv) infection in england and wales, 1990-5. | data from the national surveillance scheme for general outbreaks of intestinal disease, and the national laboratory reporting scheme were used to describe the epidemiology of small round structured virus (srsv) infections in england and wales. between 1990 and 1995, there were 7492 laboratory reports of srsv. rates of reported illness were highest among infants, young children and the elderly. during 1992-5, some 707 srsv outbreaks were reported. outbreaks in hospital wards and residential facil ... | 1998 | 9747765 |
| prevalence of human calicivirus infections in kenya as determined by enzyme immunoassays for three genogroups of the virus. | an epidemiological survey on human calicivirus (hucv) infections and associated gastroenteritis in infants was conducted to clarify the prevalence of hucv infections in infants and adults in kenya. enzyme immunoassays (eias) for three genogroups of hucvs, norwalk virus (nv), mexico virus (mxv), and sapporo virus (sv), were used to detect antigen or antibody. we tested 1,431 stool samples obtained from children younger than 6 years old with acute gastroenteritis who visited outpatient clinics in ... | 1998 | 9774557 |
| general outbreaks of infectious intestinal disease in england and wales: 1995 and 1996. | one thousand nine hundred and nineteen general outbreaks of infectious intestinal disease in england and wales were reported to the phls communicable disease surveillance centre (cdsc) between 1 january 1995 and 31 december 1996, compared with 1073 in the previous two years. a minimum data set was received for 1568 (82%) of the 1919 outbreaks. over 40,000 people were affected and about 2% of those who were ill were admitted to hospital. seventy-one deaths were reported. the duration of outbreaks ... | 1998 | 9782630 |
| seroprevalence of norwalk virus and mexico virus in chilean individuals: assessment of independent risk factors for antibody acquisition. | norwalk virus (nv) and mexico (mx) virus represent distinct genetic clusters within the same genus of human caliciviruses (cvs), a major cause of diarrhea in adults. the magnitude and potential risk factors of human cv infection in populations from santiago and punta arenas, chile, were assessed. individuals (n = 1,864) gave a blood sample and answered a questionnaire during a household survey. sera were tested for antibody to nv and mx virus with use of recombinant capsid antigens. overall, nv ... | 1998 | 9798035 |
| molecular epidemiology of "norwalk-like viruses" in outbreaks of gastroenteritis in the united states. | fecal specimens from 90 outbreaks of nonbacterial gastroenteritis reported to 33 state health departments from january 1996 to june 1997 were examined to determine the importance of and to characterize "norwalk-like viruses" (nlvs) in these outbreaks. nlvs were detected by reverse transcription-polymerase chain reaction in specimens from 86 (96%) of 90 outbreaks. outbreaks were most frequent in nursing homes and hospitals (43%), followed by restaurants or events with catered meals (26%); consump ... | 1998 | 9815206 |
| 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 |
| feline calicivirus as a model system for heat inactivation studies of small round structured viruses in shellfish. | commercial heat treatment procedures for molluscan shellfish are based on data obtained for the inactivation of hepatitis a virus (hav) in cockles. however, the most frequently reported illness associated with consumption of bivalve molluscs is gastroenteritis caused by small round structured viruses (srsvs) of the norwalk group. conditions for inactivation of srsvs are unknown. in this study a feline calicivirus was used as a model for the srsv group and conditions for its heat inactivation det ... | 1998 | 9825793 |
| molecular characterization of a bovine enteric calicivirus: relationship to the norwalk-like viruses. | jena virus (jv) is a noncultivatable bovine enteric calicivirus associated with diarrhea in calves and was first described in jena, germany. the virus was serially passaged 11 times in colostrum-deprived newborn calves and caused diarrheal disease symptoms at each passage. the complete jv genome sequence was determined by using cdna made from partially purified virus obtained from a single stool sample. jv has a positive-sense single-stranded rna genome which is 7,338 nucleotides in length, excl ... | 1999 | 9847396 |
| molecular epidemiology of outbreaks of gastroenteritis associated with small round-structured viruses in east anglia, united kingdom, during the 1996-1997 season. | during the winter season from november 1996 to may 1997, 550 fecal specimens were submitted from 94 outbreaks of gastroenteritis occurring in east anglia, united kingdom. these specimens were tested for the presence of small round-structured viruses (srsvs) by electron microscopy, reverse transcriptase pcr, or both methods. srsvs were shown to be associated with 64 of 94 (68%) of these outbreaks, of which 16 (25%) outbreaks occurred at a single location (southend) within the region. twenty-four ... | 1999 | 9854068 |
| distribution of norwalk virus within shellfish following bioaccumulation and subsequent depuration by detection using rt-pcr. | consumption of raw bivalve mollusks contaminated with pathogens from human feces continues to present a human health risk. the purpose of this study was to monitor the uptake, localization, and removal of norwalk virus (nv) in shellfish (oyster and clam) tissues by analyzing virus distribution in selected dissected tissues. live shellfish were allowed to bioaccumulate different input titers of nv for time periods from 4 to 24 h. in some experiments, depuration by shellfish that bioaccumulated nv ... | 1998 | 9874348 |
| expression and self-assembly of grimsby virus: antigenic distinction from norwalk and mexico viruses. | a cdna obtained from grimsby virus (grv), a norwalk-like virus, purified from a stool sample of a symptomatic adult associated with a gastroenteritis outbreak in the united kingdom, was used to obtain the complete nucleotide sequence of the second open reading frame (orf2). the orf2 sequence of grv predicts a capsid of 539 amino acids (aa) which exhibits aa identities of 96% to lordsdale virus, 67% to mexico virus (mxv), and 43% to norwalk virus (nv). the grv capsid protein was expressed in inse ... | 1999 | 9874680 |
| [detection of small round structured virus from oysters by rt-pcr]. | | 1998 | 9916423 |
| [outbreak of diarrhea due to srsv infection]. | | 1998 | 9922671 |
| the bovine newbury agent-2 is genetically more closely related to human srsvs than to animal caliciviruses. | the hypothesis that the enteric bovine calici-like virus newbury agent (na-2) belongs to the family caliciviridae was examined by genome sequence analysis. use of solid-phase immune electron microscopy allowed samples with good levels of virus to be identified and amplification of the genome was achieved by reverse transcription-polymerase chain reaction. examination of a 216-amino-acid sequence in the rna-dependent rna polymerase gene and a 116-amino-acid sequence in the capsid gene showed that ... | 1999 | 9927568 |