Publications

inactivation of feline calicivirus, a norwalk virus surrogate.	norwalk and norwalk virus-like particles (nvlps) [also known as small round structured viruses (srsvs)] are members of the family caliciviridae and are important causes of gastroenteritis in humans. little is known about their survival in the environment or the disinfection procedures necessary to remove them from contaminated settings. as nvlps cannot be grown in tissue culture, survival studies require the use of a closely related cultivable virus. this study assesses the survival of the surro ...	1999	9949965
an outbreak of viral gastroenteritis associated with consumption of sandwiches: implications for the control of transmission by food handlers.	although food handlers are often implicated as the source of infection in outbreaks of food-borne viral gastroenteritis, little is known about the timing of infectivity in relation to illness. we investigated a gastroenteritis outbreak among employees of a manufacturing company and found an association (rr = 14.1, 95% ci = 2.0-97.3) between disease and eating sandwiches prepared by 6 food handlers, 1 of whom reported gastroenteritis which had subsided 4 days earlier. norwalk-like viruses were de ...	1998	10030711
[rotavirus and other viruses of diarrhea].	rotaviruses represent 80% of recognized viral etiologies and 140 million cases of diarrhea per year. they strike young children with similar frequency throughout the world, but the mortality rate is high in developing countries only, with some 870,000 deaths per year (who, 1997). rotaviruses belong to the family of reoviridae; they are segmented bicatenary rna viruses, which explains their genetic variability, the presence of mixed infections, the establishment for some time already of a molecul ...	1998	10078381
recovery and detection of enterovirus, hepatitis a virus and norwalk virus in hardshell clams (mercenaria mercenaria) by rt-pcr methods.	a method for recovery of enteric viruses from hardshell clams (mercenaria mercenaria) has been developed and evaluated. seeded 50-g samples of clam tissue homogenates were processed by adsorption elution precipitation, two fluorocarbon extractions and peg precipitation. clam concentrates were assayed by infectivity and by rt-pcr after guanidinium isothiocyanate (git) extraction and/or an indirect immunomagnetic capture (ic) of the virus using paramagnetic beads. git extraction removed pcr inhibi ...	1999	10092141
a community outbreak of food-borne small round-structured virus gastroenteritis caused by a contaminated water supply.	in august 1994, 30 of 135 (23%) bakery plant employees and over 100 people from south wales and bristol in the united kingdom, were affected by an outbreak of gastroenteritis. epidemiological studies of employees and three community clusters found illness in employees to be associated with drinking cold water at the bakery (relative risk 3.3, 95%, ci 1.6-7.0), and in community cases with eating custard slices (relative risk 19.8, 95%, ci 2.9-135.1) from a variety of stores supplied by one partic ...	1999	10098798
emerging pathogens.		1994	10138458
outbreaks of gastroenteritis caused by srsvs from 1987 to 1992 in kyushu, japan: four outbreaks associated with oyster consumption.	from 1987 to 1992, 18 outbreaks of acute non-bacterial gastroenteritis occurred in kyushu district. the most common symptoms were diarrhea, vomiting, nausea and abdominal cramp. small round structured viruses (srsvs) were detected in 52 (44.8%) of 116 stool samples from 17 outbreaks by the electron microscopy (em) method, and a significant increase in the antibody level was noted in 42 (80.7%) of 52 paired serum samples from 12 outbreaks by the immune electron microscopy (iem) method and in 18 ( ...	1999	10204648
from the centers for disease control and prevention. norwalk-like viral gastroenteritis in us army trainees--texas, 1998.		1999	10208132
norwalk-like viral gastroenteritis in u.s. army trainees--texas, 1998.	during august 27-september 1, 1998, 99 (12%) of 835 soldiers in one unit at a u.s. army training center in el paso, texas, were hospitalized for acute gastroenteritis (age). their symptoms included acute onset of vomiting, abdominal pain, diarrhea, and fever. review of medical center admission records for age during the previous year indicated that fewer than five cases occurred each month. this report describes the outbreak investigation initiated on august 30 by a u.s. army epidemiologic consu ...	1999	10220254
the seroepidemiology of genogroup 1 and genogroup 2 norwalk-like viruses in italy.	southampton virus (sv) and lordsdale viruses (lv) are small round structured viruses characterised recently and belong to two separate genogroups. the capsid genes of these viruses were expressed in insect cells using recombinant baculoviruses. both sv (genogroup 1) and lv (genogroup 2) capsid proteins self-assembled to form virus-like particles (vlps). the vlps were used in a standard enzyme-linked immunosorbent assay (elisa) to screen for antibodies to sv and lv in 1,729 age-stratified human s ...	1999	10223553
identification of a distinct common strain of "norwalk-like viruses" having a global distribution.	"norwalk-like viruses" (nlvs) are the most common cause of outbreaks of nonbacterial gastroenteritis. during molecular surveillance of nlv strains from 152 outbreaks of gastroenteritis that occurred in the us between august 1993 and july 1997, we identified an nlv strain that predominated during the 1995-1996 season. the "95/96-us" strain caused 60 outbreaks in geographically distant locations within the us and was identified, by sequence comparisons, in an additional 7 countries on 5 continents ...	1999	10228052
health and safety concerns in fisheries and aquaculture.	only 10% of all foodborne illnesses in the united states are attributed to seafood, making seafood a relatively safe food commodity. the implementation of hazard analysis and critical control points guidelines should make seafood consumption even safer. concerns include closed-loop, indoor, water-recirculating production systems; harmful algal blooms in marine environments, which can cause paralytic, neurologic, amnesic, and diarrhetic shellfish poisonings and ciguatera fish poisoning; bacteria ...	1999	10329911
an outbreak of acute gastroenteritis in a geriatric long-term-care facility: combined application of epidemiological and molecular diagnostic methods.	to assess possible transmission modes of, and risk factors for, gastroenteritis associated with norwalk-like viruses (nlvs) in a geriatric long-term-care facility.	1999	10349945
[clinical analysis on an outbreak of srsv-gastroenteritis with 644 patients emerged in shizuoka prefecture].	small round structured viruses (srsv) are the major cause of acute non-bacterial enterogastritis and have a characteristic of breaking out with mass victims as food poisoning. the outbreak usually occurs among school children from school lunches in japan. a case in adults is relatively rare. the srsv food poisoning with 644 adult victims carried through lunch box broke out, which may be the biggest number in adult cases in the world. this is the report describing its outlines, analytical result ...	1999	10356895
recombinant norwalk virus-like particles given orally to volunteers: phase i study.	norwalk virus (nv) is a major cause of epidemic gastroenteritis. the nv capsid is composed of a single protein that forms recombinant (rnv) virus-like particles (vlps). in mice, these vlps are immunogenic when administered orally without adjuvant, and they elicit serum immunoglobulin (ig) g and intestinal iga responses. the aim of this study was to evaluate the safety and immunogenicity of rnv vlps in healthy volunteers.	1999	10381908
a new model system to study norwalk virus immunity.		1999	10381934
variation in orf3 of genogroup 2 norwalk-like viruses.	the nucleotide sequences of the 3'-terminal open reading frame (orf3) and 3' untranslated region (3'utr) were determined for four norwalk-like viruses (nlvs) belonging to genogroup 2. three of the viruses, isolated in 1995 and 1996, were closely related to mexico virus (92-93% nucleotide identity in orf3). the fourth virus, isolated in 1984, was unique, showing only 49-58% nucleotide identity with other nlvs. the variation in sequence of the 3'-terminal orf of nlvs was greater than that observed ...	1999	10416382
genomic diversity of "norwalk like viruses" (nlvs): pediatric infections in a brazilian shantytown.	"norwalk-like viruses" (nlvs) are a common cause of epidemic gastroenteritis in adults and children in developed countries. however, little is known about the role of nlvs in endemic pediatric gastroenteritis in developing countries. we sequenced genogroup i and ii nlv reverse transcription-polymerase chain reaction (rt-pcr) products from an 81-nucleotide region of the viral rna polymerase gene to examine the molecular epidemiology of nlv infection in children younger than 5 years of age in fort ...	1999	10421412
[detection of hav, srsv and astrovirus genomes from native oysters in chiba city, japan].	srsv, astrovirus in tvirus and hav genomes were detected by rt-pcr in naturally grown oysters (total 112) collected in chiba city bay, japan, through a year from april, 1997 to march, 1998 and genogroup was typed by sequencing. srsv positive products were detected by rt-pcr from 28 out of 112 oysters and all of them were grouped into g-ii by sequencing. the highest incidence was observed in february, 1998. furthermore, astrovirus positive products were detected sporadically from 15 out of 112 sa ...	1999	10423945
seafood-associated disease outbreaks in new york, 1980-1994.	seafood-associated disease outbreaks in new york were examined to describe their epidemiology and to identify areas for prevention and control efforts.	1999	10429753
immunoglobulin m antibody test to detect genogroup ii norwalk-like virus infection.	sera obtained from adult volunteers inoculated with genogroup ii norwalk-like viruses (nlvs), hawaii virus, and snow mountain virus and from patients involved in outbreaks of gastroenteritis were tested for genogroup ii nlv mexico virus-specific immunoglobulin m (igm) by use of a monoclonal antibody, recombinant mexico virus antigen (rmxv)-based igm capture enzyme-linked immunosorbent assay (elisa). sera from genogroup i norwalk virus (nv)-inoculated volunteers and from patients involved in a ge ...	1999	10449486
[detection of norwalk and mexico viruses, two human caliciviruses in stools of chilean children].	human calciviruses (hucvs) cause diarrhea outbreaks associated with consumption of contaminated food and water. seroepidemiological studies in developing countries, suggest that hucvs can cause acute gastroenteritis in children.	1999	10451621
seroepidemiological study of genogroup i and ii calicivirus infections in south and southern africa.	diarrhoea is associated with the daily death of between 180 and 200 children under the age of 5 years in south africa. until recently, many cases and outbreaks of diarrhoea were not associated with a known aetiologic agent. previous studies using baculovirus-expressed norwalk virus (nv) and mexico virus (mxv) capsid antigens have shown that human calicivirus infection is common in south africa. in this study, our surveillance was extended to different populations, as well as to four other southe ...	1999	10459161
detection of small round structured viruses in artificially contaminated water using filter adsorption and reverse transcription polymerase chain reaction.	the small round structured viruses (srsv) are common causes of gastroenteritis worldwide. fecally contaminated water is an important vehicle for transmission, but detection of srsv in environmental samples has been hampered by the lack of sensitive detection methods. the present work describes the detection of srsv in artificially contaminated deionized water and raw drinking water. srsv-containing fecal extracts were added to water and virus was recovered by filter adsorption-elution, followed ...	1999	10477074
detection and nucleotide sequence analysis of human caliciviruses (hucvs) from samples in non-bacterial gastroenteritis outbreaks in hokkaido, japan.	samples of feces and vomit collected from patients during 13 non-bacterial gastroenteritis outbreaks which occurred in hokkaido between 1995 and 1998 were examined by electron microscopy (em) and reverse-transcription polymerase chain reaction (rt-pcr) for evidence of infection with human caliciviruses (hucvs). in 6 food-borne outbreaks, oysters were the probable source of infection, while the origin of hucvs was not found out for the other 7 outbreaks. one-hundred-eleven of 214 stool, vomit and ...	1999	10480550
x-ray crystallographic structure of the norwalk virus capsid.	norwalk virus, a noncultivatable human calicivirus, is the major cause of epidemic gastroenteritis in humans. the first x-ray structure of a calicivirus capsid, which consists of 180 copies of a single protein, has been determined by phase extension from a low-resolution electron microscopy structure. the capsid protein has a protruding (p) domain connected by a flexible hinge to a shell (s) domain that has a classical eight-stranded beta-sandwich motif. the structure of the p domain is unlike t ...	1999	10514371
a multiplex reverse transcription polymerase chain reaction method for the detection of foodborne viruses.	a multiplex reverse transcription polymerase chain reaction (rt-pcr) method was developed for the simultaneous detection of the human enteroviruses, hepatitis a virus (hav) and norwalk virus (nv). poliovirus type 1 (pv1) was chosen as a model for the human enterovirus group. three different sets of primers were used to produce three size-specific amplicons of 435 bp, 270 bp, and 192 bp for pv1, nv, and hav, respectively. rt-pcr products were separated by agarose gel electrophoresis, and amplicon ...	1999	10528729
foodborne diseases: seafood.		1999	10530590
a hospital outbreak of gastroenteritis possibly related to the contamination of tap water by a small round structured virus.	small round structured viruses (srsvs) are a major cause of gastroenteritis in institutions and sensitive new molecular techniques allow rapid diagnosis and the establishment of control measures. in january 1999, a 10 day-long outbreak of gastroenteritis in a re-education ward, was reported by a hospital hygiene department. a potential common source of contamination was tap water. the stools of six patients with gastroenteritis and seven tap water samples from the hospital ward, were tested for ...	1999	10549314
norwalk and "norwalk-like viruses" in epidemic gastroenteritis.	despite the lack of a cell culture or animal model system, the past decade has seen tremendous advances in our understanding of nlv. prior to 1990, the only nucleotide sequence information for caliciviruses was from viruses isolated from animals. there are now sequences available for more than 100 nlv isolates and more are rapidly accumulating. such information is being used for development of new and more sensitive diagnostic assays. the cdc, under the national food safety initiative and in coo ...	1999	10549432
outbreak of viral gastroenteritis due to drinking water contaminated by norwalk-like viruses.	heinävesi, a finnish municipality with a population of 4860 inhabitants, had an outbreak of gastroenteritis in march 1998. on the basis of an epidemiologic survey, an estimated 1700-3000 cases of acute gastroenteritis occurred during the outbreak. municipal water consumption was found to be associated with illness (risk ratio [rr]=3.5, 95% confidence interval, 3.11>rr>3.96). norwalk-like virus (nlv) genogroup ii (ggii) was identified in untreated water, treated water, and 4 tap water samples by ...	1999	10558930
open reading frame 1 of the norwalk-like virus camberwell: completion of sequence and expression in mammalian cells.	the orf1 sequence was determined for camberwell virus, a genogroup 2 norwalk-like virus, completing the full genome of 7,555 nucleotides. orf1 cdna was cloned into a simian virus 40-based expression vector, and the viral proteins synthesized following transfection into cos cells were analyzed. by using antisera directed against the helicase, protease, or polymerase regions, eight polypeptides ranging in size from 19 to 117 kda were detected by radioimmunoprecipitation. the cleavage sites determi ...	1999	10559373
seroprevalence against norwalk-like human caliciviruses in beijing, china.	serum specimens from 1,109 individuals at different ages in beijing, china, were collected between april 1996 and march 1997 and tested for igg antibodies against human caliciviruses using enzyme immune assays (eias). baculovirus-expressed recombinant norwalk virus (rnv) and mexican virus (rmxv) capsid proteins were used as antigens. the seroprevalence was 89% for rnv and 91% for rmxv. similar seroprevalence between the two antigens was observed in individual age groups and both genders. infants ...	2000	10568770
molecular detection of norwalk-like caliciviruses in sewage.	in this study, norwalk-like virus (nlv) rna was detected by reverse transcriptase pcr (rt-pcr) in sewage water concentrates. sequence analysis of the rt-pcr products revealed identical sequences in stools of patients and related sewage samples. in 6 of 11 outbreak-unrelated follow-up samples, multiple nlv genotypes were present. levels as high as 10(7) rna-containing particles per liter were found. these data show that high loads of nlvs may be present in sewage and warrant further studies addre ...	1999	10584031
virus survey in environmental waters in miyagi prefecture.		1999	10592906
confirmation of norwalk-like virus amplicons after rt-pcr by microplate hybridization and direct sequencing.	a large number of norwalk-like viruses (nlvs) have been identified from stool samples by rt-pcr by amplifying part of the polymerase-coding gene. a set of probes were selected based on sequence analysis of the viruses circulating in finland during the years 1996-97 for confirmation of the findings by hybridization. a microplate hybridization test, which provides a rapid semi-automatic detection for pcr products, was designed and compared with agarose gel electrophoresis. from the material of 210 ...	1999	10598090
design and evaluation of a primer pair that detects both norwalk- and sapporo-like caliciviruses by rt-pcr.	a primer pair (p289/290) based on the rna polymerase sequence of 25 prototype and currently circulating strains of human caliciviruses (hucvs) was designed for the detection of both norwalk-like caliciviruses (nlvs) and sapporo-like caliciviruses (slvs) by reverse transcription-polymerase chain reaction (rt-pcr). this primer pair produces rt-pcr products of 319 bp for nlvs and 331 bp for slvs. the usefulness of this primer pair was shown by its detection of prototype nlvs (norwalk, snow mountain ...	1999	10598092
development of methods to detect "norwalk-like viruses" (nlvs) and hepatitis a virus in delicatessen foods: application to a food-borne nlv outbreak.	"norwalk-like viruses" (nlvs) and hepatitis a virus (hav) are the most common causes of virus-mediated food-borne illness. epidemiological investigations of outbreaks associated with these viruses have been hindered by the lack of available methods for the detection of nlvs and hav in foodstuffs. although reverse transcription (rt)-pcr methods have been useful in detecting nlvs and hav in bivalve mollusks implicated in outbreaks, to date such methods have not been available for other foods. to a ...	2000	10618226
[rotavirus and other gastroenteritis viruses].		1999	10635837
norwalk-like calicivirus genes in farm animals.	viruses closely related to norwalk-like viruses (nlvs) were recently found in stored stool samples from two calves (united kingdom and germany) and four pigs (japan), sparking discussions about the potential for zoonotic transmission. to investigate if nlvs are commonly present in farm animals, pooled stool samples from 100 pig farms, 48 chicken farms, 43 dairy cow herds, and 75 veal calf farms from the netherlands were assayed by reverse transcription- polymerase chain reaction amplification, u ...	2000	10653567
investigation of an outbreak of gastroenteritis caused by norwalk-like virus, using solid phase immune electron microscopy.	in february 1993, 95 persons (47 patients and 48 staff members) were affected by an hospital outbreak of viral gastroenteritis. using direct electron microscopy (em) the causative agent was identified as a small round structured virus. this was confirmed as a norwalk-like virus using solid phase immune electron microscopy (spiem). of 94 stool samples examined, 12 (13%) samples containing small round structured viruses (srsv) were spiem positive for norwalk-like virus. a further 25 (27%) samples ...	2000	10662561
shipboard impact of a probable norwalk virus outbreak from coastal japan.	norwalk virus has been implicated in shipboard diarrheal disease outbreaks throughout asia. a large outbreak of suspected norwalk virus was investigated on a u.s. naval aircraft carrier following the clinical recognition of 450 cases of gastroenteritis over a 2-week period (september 14-28, 1997) during coastal exercises. a random sampling of 44 cases from 450 personnel who sought medical attention was compared with 19 controls. junior enlisted sailors and marines comprised 97% of all cases. the ...	1999	10674667
norwalk-like virus and bacterial pathogens associated with cases of gastroenteritis onboard a us navy ship.	acute gastroenteritis is a potential cause of substantial morbidity in u.s. military personnel during deployment. this study investigated the microbial causes of diarrhea in u.s. troops on exercises in southeast asia aboard the u.s.s. germantown from march through may 1996. a total of 49 (7%) patients with diarrhea reported to sick call during a 3-month deployment involving 721 personnel. diarrheal samples from 49 patients were subjected to bacterial and parasitologic examination, but sufficient ...	1999	10674668
expression of recombinant norwalk-like virus capsid proteins using a bacterial system and the development of its immunologic detection.	the capsid protein of norwalk-like virus (nlv) isolates nlv-36 (mexico virus type, genogroup ii [gii]), nlv-21 (lordsdale virus type, gii), nlv-114 (untyped gii virus), and nlv-96-908 (ky89 virus type, gi) have been expressed in an escherichia coli system. the expressed recombinant nlv capsid proteins, fused with maltose binding protein (mbp-rv) and thioredoxin (trx-rv) in e. coli lysate, were analyzed using sodium dodecyl sulfate-polyacrylamide gel eletrophoresis. rabbit igg (r-igg) in hyperimm ...	2000	10686033
summer vomiting disease?		1999	10721376
outbreaks of norwalk-like viral gastroenteritis--alaska and wisconsin, 1999.	norwalk-like viruses (nlvs) are the most common cause of epidemic gastroenteritis in the united states, resulting in illness in approximately 23 million persons each year . persons of all ages are affected because previous infection confers only short-term immunity. most nlv gastroenteritis outbreaks involve foodborne or person-to-person transmission. this report presents investigations of a foodborne nlv outbreak in alaska and person-to-person transmission in wisconsin.	2000	10738840
evaluation of f-specific rna bacteriophage as a candidate human enteric virus indicator for bivalve molluscan shellfish.	escherichia coli is a widely utilized indicator of the sanitary quality of bivalve molluscan shellfish sold for human consumption. however, it is now well documented that shellfish that meet the e. coli standards for human consumption may contain human enteric viruses that cause gastroenteritis and hepatitis. in this study we investigated using f-specific rna bacteriophage (frna bacteriophage) to indicate the likely presence of such viruses in shellfish sold for consumption. frna bacteriophage a ...	2000	10742200
selective accumulation may account for shellfish-associated viral illness.	from 1991 through 1998, 1,266 cases of shellfish-related illnesses were attributed to norwalk-like viruses. seventy-eight percent of these illnesses occurred following consumption of oysters harvested from the gulf coast during the months of november through january. this study investigated the ability of eastern oysters (crassostrea virginica) to accumulate indicator microorganisms (i.e., fecal coliforms, escherichia coli, clostridium perfringens, and f(+) coliphage) from estuarine water. one-w ...	2000	10742214
seroprevalence and seroincidence of norwalk-like virus infection among brazilian infants and children.	to determine the importance of norwalk-like viruses (nlvs) as pediatric pathogens in a developing country, the seroprevalence and seroincidence of this group of viruses in a cohort of children less than 4 years of age in an urban shantytown in northeastern brazil was examined. serum samples were collected approximately every 6 months from 135 children who were surveyed three times each week for diarrhea and vomiting. nlv igg was measured by an enzyme immunosorbent assay (eia) with recombinant no ...	2000	10745243
a diagnostic eia for detection of the prevalent srsv strain in united kingdom outbreaks of gastroenteritis.	small round structured viruses (srsvs) are the major cause of outbreaks of gastroenteritis in the uk. diagnosis is problematic due to insensitive electron microscopy (em) or technically demanding reverse transcription polymerase chain reaction (rt-pcr) techniques. we have studied outbreaks of non-bacterial gastroenteritis using an eia based upon recombinant capsid protein from the currently prevalent circulating strain of srsv (lordsdale genotype ii) and compared its performance against em and r ...	2000	10745245
identification of an epitope common to genogroup 1 "norwalk-like viruses".	a panel of 10 monoclonal antibodies (mabs) to recombinant norwalk virus (nv) capsid protein were tested in competition enzyme-linked immunosorbent assays. patterns of competition indicated that these mabs recognize six to eight epitopes covering five nonoverlapping regions of the capsid protein. a single epitope, recognized by nv mabs nv3901, nv3912, and nv2461 was found to occur in the majority of genogroup 1 (g1) but not genogroup 2 (g2) "norwalk-like viruses" (nlvs). this observation supports ...	2000	10747162
genetic polymorphism across regions of the three open reading frames of "norwalk-like viruses".	genomic characterization of norwalk-like human caliciviruses (nlvs) originating from outbreaks and sporadic cases of acute gastroenteritis has revealed surprisingly high levels of diversity, even in the rna polymerase gene, which is anticipated to be highly conserved. since information on antigenic relationship is limited, due to the lack of a tissue culture system for these viruses, strains mostly are described on the basis of their genetic relatedness. however, the lack of uniformly applied cr ...	2000	10752550
a foodborne outbreak of gastroenteritis associated with norwalk-like viruses: first molecular traceback to deli sandwiches contaminated during preparation.	in march 1998, an outbreak of acute gastroenteritis occurred among students at a texas university. overall, 125 ill students sought medical care. case-control studies revealed that illness was significantly associated with eating foods from the university's main cafeteria deli bar on 9 and 10 march. stool specimens from 9 (50%) of 18 ill students and samples of deli ham showed evidence of norwalk-like viruses (nlvs) by reverse-transcriptase (rt) polymerase chain reaction (pcr) assay. a food hand ...	2000	10753727
norwalk-like viral gastroenteritis outbreak in u.s. army trainees.	an outbreak of acute gastroenteritis hospitalized 99 (12%) of 835 u. s. army trainees at fort bliss, el paso, texas, from august 27 to september 1, 1998. reverse transcriptase polymerase chain reaction tests for norwalk-like virus were positive for genogroup 2. gastroenteritis was associated with one post dining facility and with soft drinks.	2000	10756159
a series of outbreaks of food poisoning?	a series of independently occurring episodes which were notified individually as 'food poisoning' were, after investigation, linked to a common source water supply.	2000	10777225
molecular epidemiology of outbreaks of gastroenteritis associated with small round structured viruses in germany in 1997/98.	the molecular epidemiology of small round structured viruses (srsvs) in germany was studied using fecal specimens from 16 srsv-associated gastroenteritis outbreaks in different parts of germany during 1997/1998 by reverse transcription-polymerase chain reaction (rt-pcr) and by sequencing of the orf1 and orf3 amplicons. the majority of the isolates clustered in one subtype and were closely related to published srsv sequences of genogroup ii.	2000	10795514
introduction: human enteric caliciviruses-an emerging pathogen whose time has come.		2000	10804132
summary of the first international workshop on human caliciviruses.		2000	10804133
the epidemiology of enteric caliciviruses from humans: a reassessment using new diagnostics.	in the united states, acute gastroenteritis is one of the most commonly noted illnesses on hospital discharge records and death certificates, yet few of these cases have an etiologic diagnosis. the application of new molecular diagnostic methods has shown caliciviruses (previously referred to as the norwalk family of viruses or small round structured viruses) to be the most common cause of acute gastroenteritis (age) outbreaks in the united states, and they may emerge as a common cause of sporad ...	2000	10804134
molecular epidemiology of human enteric caliciviruses in the netherlands.	in the netherlands, illness due to norwalk-like viruses (nlvs) of the family caliciviridae is quite common. nlvs cause >80% of the outbreaks of gastroenteritis reported to municipal public health centers and at least 5% of the cases of gastroenteritis for which a general practitioner is consulted. in addition, up to 18% of community cases of gastroenteritis in the 1998/1999 winter season have been attributed to nlvs. patterns of disease activity differ remarkably, with "normal years, when outbre ...	2000	10804135
surveillance of viral gastroenteritis in japan: pediatric cases and outbreak incidents.	surveillance results from pediatric cases and outbreaks of viral gastroenteritis in japan are presented. in winter, both small round structured virus (srsv, or norwalk-like viruses) and rotavirus were detected from infants with gastroenteritis; however, in recent years, the prevailing time of srsv infection has preceded that of rotavirus infection. most nonbacterial gastroenteritis outbreaks were related to srsv infection, and >60% of the outbreaks were caused by contaminated food. in small-size ...	2000	10804136
epidemiology of calicivirus infections in sweden, 1994-1998.	outbreaks of acute gastroenteritis are frequently caused by caliciviruses. electron microscopy was used to search for these viruses in fecal samples from patients with acute gastroenteritis. of 5800 samples collected and analyzed from november 1994 to june 1998, 3700 were associated with outbreaks. a total of 676 outbreaks were analyzed, and viruses were found in 67%. caliciviruses, usually norwalk-like viruses (nlvs), were found in 407 (89%) of 455 outbreaks, while sapporo-like viruses were ide ...	2000	10804137
the impact of foodborne calicivirus disease: the minnesota experience.	the first outbreaks of norwalk virus gastroenteritis in minnesota were confirmed in 1982. since then, norwalk-like caliciviruses have been recognized to be the most common cause of foodborne disease outbreaks, accounting for 41% of all confirmed foodborne outbreaks in minnesota from 1981-1998. although laboratory confirmation of caliciviruses in stool samples was not attempted in most of these outbreaks, all conformed to epidemiologic criteria for defining outbreaks of norwalk virus. since 1996, ...	2000	10804138
cold weather seasonality of gastroenteritis associated with norwalk-like viruses.	norwalk-like viruses (nlvs) are the most common cause of acute nonbacterial gastroenteritis in adults, but little is known about their seasonality. the lack of specific diagnostic tools impeded study of these viruses in the past, and surveys using electron microscopy often grouped nlvs with other unrelated viruses. a search of the scientific literature found eight surveys of gastroenteritis, which were conducted for at least 1 year, that specifically identified nlvs. unpublished data from labora ...	2000	10804139
the discovery of the 27-nm norwalk virus: an historic perspective.	in 1972, a 27-nm virus-like particle was discovered by use of immune electron microscopy (iem) in an infectious stool filtrate derived from an outbreak of gastroenteritis in an elementary school in norwalk, ohio. iem enabled the direct visualization of antigen-antibody interaction, as the particles were aggregated and coated by specific antibodies. this allowed the recognition and identification of a 27-nm virus-like particle that did not have a distinctive morphology, was low-titered, and was a ...	2000	10804141
organization and expression of calicivirus genes.	the application of molecular techniques to the characterization of caliciviruses has resulted in an extensive database of sequence information. this information has led to the identification of 4 distinct genera. the human enteric caliciviruses have been assigned to 2 of these genera. this division is reflected not only in sequence diversity but in a fundamental difference in genome organization. complete genome sequences are now available for 5 enteric caliciviruses and demonstrate that human a ...	2000	10804143
structural studies of recombinant norwalk capsids.	norwalk virus is the major cause of epidemic viral gastroenteritis in humans. attempts to grow this human virus in laboratory cell lines have been unsuccessful; however, the norwalk virus capsid protein, when expressed in insect cells infected with a recombinant baculovirus, spontaneously assembles into virus-like particles. the x-ray crystallographic structure of these recombinant norwalk particles has been determined to 3.4 a, using a 22-a electron cryomicroscopy structure as a phasing model. ...	2000	10804144
taxonomy of the caliciviruses.	the international committee on taxonomy of viruses (ictv) has recently approved several proposals submitted by the present caliciviridae study group. these proposals include the division of the family into 4 new genera designated lagovirus, vesivirus, "norwalk-like viruses (nlvs), and "sapporo-like viruses (slvs); the latter 2 genera were assigned temporary names until acceptable names can be determined by the scientific community. the genera have been further divided into the following species: ...	2000	10804145
immunity to calicivirus infection.	the evolution of our understanding of immunity to calicivirus infection, using norwalk virus as the prototype, is discussed in three stages: (1) "ancient times (1972-1978), when human volunteer studies prevailed, (2) the "middle ages (1978-1990), which were characterized by the development and implementation of solid-phase immunoassays based on native viral antigens, and (3) "modern times (1990 to present), which began with the cloning of the genome of the noncultivatable 8fiia strain of norwalk ...	2000	10804146
genetic classification of "norwalk-like viruses..	reverse transcription-polymerase chain reaction has been used worldwide for the diagnosis of norwalk-like virus (nlv) infection, yet a commonly accepted genetic classification scheme has not been established. amino acid sequences from four regions of open-reading frame 2 (orf2) were used to analyze 101 nlv strains, including 2 bovine strains. on the basis of this analysis, a genetic classification scheme is proposed that differentiates 99 human strains into 2 major genetic groups consisting of 5 ...	2000	10804147
diagnosis of human caliciviruses by use of enzyme immunoassays.	the application of molecular technologies, such as the expression of viral proteins in baculovirus, has provided a powerful approach to the diagnosis of human calicivirus (hucv) infections. the baculovirus-expressed hucv capsid protein self-assembles into virus-like particles, providing excellent reagents for immunologic assays, such as enzyme immunoassays (eias). following the expression of the capsid protein of norwalk virus, the capsid proteins of 8 other hucv strains have been expressed in b ...	2000	10804148
detection of norwalk-like virus in shellfish implicated in illness.	in the 1990s, norwalk-like viruses (nlvs) were identified in patient specimens as the primary pathogen associated with shellfish-borne gastroenteritis in the united states. identification of these viruses from implicated shellfish has been difficult due to inefficient recovery of viruses, natural polymerase chain reaction (pcr) inhibitors in shellfish, and low virus contamination. recent improvements to the method of detecting nlvs in shellfish include enhanced processing of virus and shellfish ...	2000	10804149
norwalk virus vaccines: challenges and progress.	human caliciviruses (hucvs) are the major cause of outbreaks of acute nonbacterial gastroenteritis throughout the world. an increasing recognition of the clinical significance of these viruses as human pathogens causing foodborne and waterborne disease indicates that an effective vaccine would be useful. this article reviews the current challenges that exist for the development of a vaccine for the hucvs as well as the status of development of a candidate vaccine. hucvs are viruses that exhibit ...	2000	10804150
multi-state outbreaks of acute gastroenteritis traced to fecal-contaminated oysters harvested in louisiana.	norwalk-like viruses (nlvs), or small round structured viruses, are known to cause acute gastroenteritis associated with eating contaminated shellfish. between 1993 and 1996, three oyster-related gastroenteritis outbreaks attributed to nlv occurred in louisiana. intensive trace-back and environmental investigations revealed that the overboard disposal of sewage by oyster harvesters into oyster-bed waters was the most likely source of contamination in at least two of the outbreaks. the small infe ...	2000	10804152
norwalk-like virus infection in military forces: epidemic potential, sporadic disease, and the future direction of prevention and control efforts.	the impact of norwalk-like virus (nlv) infection on military forces is evaluated in this report. nlvs were a major cause of both outbreaks and sporadic disease among crowded us ground troops in the 1991 war with iraq. nlvs also have been found to be a cause of acute gastroenteritis in other ground and shipboard deployments. four large outbreaks of acute gastroenteritis were investigated aboard us navy aircraft carriers between 1992 and 1997. in these outbreaks, nlvs were identified as the probab ...	2000	10804153
possible community immunity to small round structured virus gastroenteritis in a rural aboriginal community.	in april 1998 an outbreak of gastroenteritis affected visitors, but none of the aboriginal residents, at a territory health services luncheon in a rural aboriginal community in central australia. the epidemiological features and identification of small round structured virus (srsv) from two participants suggest that this was an outbreak caused by a srsv. the attack rate in the visitors who ate or drank food at the luncheon was 73% (11 of 15). seventeen aboriginal residents were interviewed, none ...	2000	10812750
members of the family caliciviridae (norwalk virus and sapporo virus) are the most prevalent cause of gastroenteritis outbreaks among infants in japan.	norwalk virus (nv) and sapporo virus (sv) were approved as type species of the genus norwalk-like viruses and the genus sapporo-like viruses, respectively, within the family caliciviridae. to clarify the importance of nv and sv as causes of gastroenteritis outbreaks in infants, stool samples obtained from 36 outbreaks of nonbacterial gastroenteritis that occurred during 1976-1995 in an infant home in sapporo, japan, were examined for diarrhea viruses using electron microscopy, enzyme immunoassay ...	2000	10837186
the detection of small round-structured viruses in water and environmental materials.	a procedure for concentrating small round-structured viruses (srsvs) (norwalk-like viruses) from water and other environmental materials is described. primers based on the helicase region of the srsv genome were confirmed as specific by reaction with typed specimens, and used to detect virus in concentrates of unseeded and seeded samples. virus was detected in estuarine recreational water polluted by untreated sewage, although not in seawater samples taken some distance from outfall discharges. ...	2000	10856757
the heteroduplex mobility assay (hma) as a pre-sequencing screen for norwalk-like viruses.	molecular epidemiological studies of norwalk-like viruses (nlvs), previously known as small round structured viruses (srsvs), are dependant currently on dna sequencing of pcr amplicons, which is expensive and time consuming. the heteroduplex mobility assay (hma) was evaluated as a method for identification of pcr amplicons from the commonly circulating nlv strains without dna sequencing. the procedure was developed for use with two reference strains, a mexico virus-like strain (mxv-like; hu¿nlv¿ ...	2000	10856763
[genetic characterization of norwalk-like viruses (nlvs) detected in japan from 1989 to 1998 and establishment of consensus primers].	by means of reverse transcription-polymerase chain reaction using various pairs of primers, 902 strains of norwalk-like viruses (nlvs) were detected during 10 years from 1989 to 1998 in the nationwide area of japan including hokkaido and okinawa. nucleotide sequencing was done on 177 strains, and we found that 153 strains (86%) of them belonged to geno-group ii (gii). gii could be classified into five subgroups (g2a, g2b, g2c, g2d and g2e) based on the amino acid sequences showing a similarity o ...	2000	10860360
norwalk virus open reading frame 3 encodes a minor structural protein.	norwalk virus (nv) is a causative agent of acute epidemic nonbacterial gastroenteritis in humans. the inability to cultivate nv has required the use of molecular techniques to examine the genome organization and functions of the viral proteins. the function of the nv protein encoded by open reading frame 3 (orf 3) has been unknown. in this paper, we report the characterization of the nv orf 3 protein expressed in a cell-free translation system and in insect cells and show its association with re ...	2000	10864672
simultaneous detection and genotyping of "norwalk-like viruses" by oligonucleotide array in a reverse line blot hybridization format.	"norwalk-like viruses" (nlvs) are the most common cause of outbreaks of nonbacterial gastroenteritis worldwide. to date, the method most widely used for typing of nlv strains is sequencing and subsequent phylogenetic analysis of reverse transcription (rt)-pcr products, which has revealed the existence of stable distinct lineages (genotypes). this typing method is rather costly, not routinely used in clinical laboratories, and not very suitable for the analysis of large numbers of samples. theref ...	2000	10878050
major change in the predominant type of "norwalk-like viruses" in outbreaks of acute nonbacterial gastroenteritis in osaka city, japan, between april 1996 and march 1999.	in osaka city, japan, between april 1996 and march 1999, a total of 350 fecal specimens from 64 outbreaks of acute nonbacterial gastroenteritis were examined to investigate infection by "norwalk-like viruses" (nlvs). by reverse transcription (rt)-pcr, 182 samples (52.0%) from 47 outbreaks (73.4%) were nlv positive. during those three years, the incidence of nlv-associated outbreaks showed seasonality, being higher during january to march (winter to early spring). the ingestion of contaminated oy ...	2000	10878058
a novel "small round virus" inducing poult enteritis and mortality syndrome and associated immune alterations.	the role of a novel "small round virus" (srv) isolated from poult enteritis and mortality syndrome (pems) cases in inducing pems and associated immune alterations was examined in this study. specific-pathogen-free and conventional poults were orally challenged with srv and/or turkey coronavirus and monitored for clinical signs. intestines, thymus, bursa, and spleens were examined for srv antigen at various days postinoculation (dpi). peripheral blood lymphocytes (pbls), thymocytes, and splenic l ...	2000	10879906
viral agents associated with poult enteritis and mortality syndrome: the role of a small round virus and a turkey coronavirus.	intestinal samples from turkey poults affected with poult enteritis and mortality syndrome (pems) were examined for viruses by immune electron microscopy and double-stranded rna virus genome electropherotyping. turkey coronavirus (tcv), avian rotaviruses, reovirus, and a yet undefined small round virus (srv) were detected. the srv and tcv were isolated and propagated in turkey embryos. challenge of specific-pathogen-free turkey poults with srv, tcv, or both resulted in mortality and clinical res ...	2000	10879909
human immune responses to a novel norwalk virus vaccine delivered in transgenic potatoes.	a new approach for delivering vaccine antigens is the use of inexpensive, plentiful, plant-based oral vaccines. norwalk virus capsid protein (nvcp), assembled into virus-like particles, was used as a test antigen, to determine whether immune responses could be generated in volunteers who ingested transgenic potatoes. twenty-four healthy adult volunteers received 2 or 3 doses of transgenic potato (n=20) or 3 doses of wild-type potato (n=4). each dose consisted of 150 g of raw, peeled, diced potat ...	2000	10882612
[development of molecular tests for rapid detection of enteropathogens].	amplification of specific dna sequences by polymerase chain reaction (pcr), enables rapid, sensitive and direct, specific identification of pathogens at very low concentrations in clinical samples. studies in recent years have reported identification of several enteropathogens directly from stool samples by pcr. the amplification process includes the use of primers complementary to the dna sequences specific to the pathogen, thus relying on the pathogen's genotype, rather than its phenotype on w ...	2000	10883231
evaluation of nine sets of pcr primers in the rna dependent rna polymerase region for detection and differentiation of members of the family caliciviridae, norwalk virus and sapporo virus.	norwalk virus and sapporo virus were approved as type species of the genus "norwalk-like viruses" and the genus "sapporo-like viruses," respectively, in the family caliciviridae. a total of 116 stool specimens containing norwalk virus (nv) or sapporo virus (sv) were tested by rt-pcr and southern hybridization to evaluate nine sets of pcr primers and seven internal oligonucleotide probes in the rna dependent rna polymerase region of nv and sv for detection and differentiation of viruses in the nv ...	2000	10888362
infantile convulsions with mild gastroenteritis.	the development of sensitive new molecular genetic techniques has led to the detection of rotavirus in cerebrospinal fluid, stools and throat swabs from patients with gastroenteritis with accompanying clinical symptoms similar to infantile benign convulsions. small round structured virus (srsv) has also been found in stools of patients with similar clinical symptoms by a new procedure. however, the mechanism by which these viral infections induce benign convulsions remains to be elucidated. the ...	2000	10891637
combined infection of norwalk-like virus and verotoxin-producing bacteria associated with a gastroenteritis outbreak.	detection of multiple pathogens, particularly a combination of viruses and bacteria, is infrequently documented in outbreaks of gastroenteritis. this paper reports the presence of norwalk-like virus (nlv) and enterohaemorrhagic verotoxin-producing escherichia coli in one individual, and nlv and verotoxin-producing aeromonas sobria in another individual, both part of a large gastroenteritis outbreak. the causes of gastroenteritis in such outbreaks may be more complex than previously thought.	1999	10892495
antigenic diversity of norwalk-like viruses: expression of the capsid protein of a genogroup i virus, distantly related to norwalk virus.	the gene encoding the capsid protein of a genogroup i norwalk-like virus (nlv) (hu/nlv/stav/95/nor) was cloned and expressed in insect cells using a baculovirus vector. the his-tagged recombinant capsid protein (rstav) was antigenic and immunogenic, showed an apparent molecular weight of approximately 68 kd in protein gels, and was only soluble under denaturing conditions. the amino acid sequence of the rstav protein showed 65-88% similarity to capsid protein sequences from other genogroup i nlv ...	2000	10893150
infectious diseases of gastrointestinal tract in adolescents.	this article reviews the following gastrointestinal infections: esophagitis, gastritis, duodenitis including duodenal ulcers, and enteritis (gastroenteritis). the epidemiology, risk factors, microbiology and pathogenesis, diagnosis, treatment, morbidity/mortality, and prevention are discussed in relation to the most important pathogens. the symptoms and pathogenesis of esophagitis caused by candida albicans and herpes simplex are contrasted with the symptoms of esophagitis caused by helicobacter ...	2000	10916124
three-year study to assess human enteric viruses in shellfish.	the main pathogenic enteric viruses able to persist in the environment, such as hepatitis a virus (hav), norwalk-like virus (nlv), enterovirus (ev), rotavirus (rv), and astrovirus (av), were detected by reverse transcription-pcr and hybridization in shellfish during a 3-year study. oyster samples (n = 108), occasionally containing bacteria, were less frequently contaminated, showing positivity for av (17%), nlv (23%), ev (19%), and rv (27%), whereas mussel samples, collected in areas routinely i ...	2000	10919776
enteric virus infections and diarrhea in healthy and human immunodeficiency virus-infected children.	forty-three stool samples from 27 human immunodeficiency virus (hiv)-seropositive children and 38 samples from 38 hiv-negative children, collected during a 15-month period, were examined for enteric viruses. diagnostic assays included enzyme immunoassays for rotavirus, adenovirus, and norwalk virus; polyacrylamide gel electrophoresis for picobirnavirus and atypical rotavirus; and pcr for astrovirus and enterovirus. specimens from hiv-positive children were more likely than those of hiv-negative ...	2000	10921942
[norwalk virus-like food poisoning after eating oysters].	the aim of this study was to conduct a clinical-epidemiological and microbiological investigation into an outbreak of food-borne disease due to the consumption of oysters.	2000	10923321
distinct epidemiological patterns of norwalk-like virus infection.	norwalk-like viruses (nlv) are important economically as a cause of both sporadic gastroenteritis in the community and large outbreaks in hospitals and other institutional settings. despite the description of several antigenic types relatively little is known about the epidemiology of these individual types. nlvs were detected by electron microscopy in faecal specimens from 706 outbreaks of gastroenteritis that represented 68% of all outbreaks of non-bacterial gastroenteritis. these outbreaks to ...	2000	10935995
norwalk-like virus as a cause of a gastroenteritis outbreak in a childcare centre.		2000	10937421
detection of sporadic cases of norwalk-like virus (nlv) and astrovirus infection in a single irish hospital from 1996 to 1998.	'norwalk-like viruses' (nlv) and astroviruses are recognised as the most important etiologic agents of viral gastroenteritis, excluding rotaviruses. however, neither of these two groups of viruses is routinely screened for in irish hospital laboratories.	2000	10942091
foodborne viral illness--status in australia.	norwalk-like virus contamination of oysters and orange juice, and hepatitis a virus contamination of oysters have been responsible for large outbreaks of foodborne viral disease in australia. rotavirus, adenovirus, astrovirus, parvovirus and other enteroviruses also contribute to the incidence of gastroenteritis in this country but the role of foods and waters in transmitting these viruses is unclear. protocols for the investigation, surveillance and reporting of foodborne viral illness require ...	2000	10946844
interaction of cellular proteins with the 5' end of norwalk virus genomic rna.	the lack of a susceptible cell line and an animal model for norwalk virus (nv) infection has prompted the development of alternative strategies to generate in vitro rnas that approximate the authentic viral genome. this approach has allowed the study of viral rna replication and gene expression. in this study, using mobility shift and cross-linking assays, we detected several cellular proteins from hela and caco-2 cell extracts that bind to, and form stable complexes with, the first 110 nucleoti ...	2000	10954557