Publications

a foodborne outbreak of norwalk virus gastroenteritis. evidence for post-recovery transmission.	from november 10-16, 1982, 220 (57%) of 383 attendees at eight banquets for which food had been prepared at a single hotel restaurant and the employees of the hotel had onset of norwalk virus gastroenteritis. epidemiologic investigation of the three largest banquets confirmed consumption of potato and fruit salads (banquet a), coleslaw (banquet b), and tossed salad (banquet c) to be significantly associated with illness. between november 8-19, similar illness occurred in seven (54%) of 13 hotel ...	1986	3013001
leads from the mmwr. gastroenteritis on two caribbean cruise ships.		1986	3014174
enzyme-linked immunosorbent assays for snow mountain and norwalk agents of viral gastroenteritis.	enzyme-linked immunosorbent assays (elisas) for antigen detection and blocking elisas for serum antibody rises were developed for the snow mountain and norwalk agents of viral gastroenteritis. the elisas were as sensitive as the existing radioimmunoassays and were specific for the snow mountain or norwalk agent. the blocking elisas detected the same number of significant rises in antibodies to these agents as did the existing blocking radioimmunoassays.	1986	3020085
pathogens that cause travelers' diarrhea in latin america and africa.	with the advent of rapid and convenient means of transportation, millions of persons travel each year from industrialized to developing countries in the tropics and subtropics. these travelers are at risk for a variety of infectious diseases that are endemic in these areas; the most frequently occurring of these is diarrhea. studies of groups of travelers to latin america and africa have found that approximately one-half develop diarrhea during their stay abroad. etiologic investigations of thes ...	1986	3014633
pediatric viral gastroenteritis.	rotavirus and norwalk agent cause most viral gastroenteritis in the pediatric population. infection results in osmotic diarrhea, which can cause dehydration and acidosis. oral rehydration therapy has been shown worldwide to be a safe and effective means of treating this disease. formula feeding should be resumed as soon as possible; breast feeding should be maintained throughout the illness. admission criteria are based on weight loss, serum sodium level and ability to rehydrate orally on an out ...	1986	3014849
human viruses in sediments, sludges, and soils.	recent studies have provided a greater understanding of the movement of viruses in the environment by their attachment to solids. these studies have focused on solids-associated viruses present in wastewater discharged into the ocean and on viruses in sludge and wastewater that may be retained in soil following their land disposal. such ocean or land disposal of wastewater and sludge may result in a discharge of one or more of 120 human enteric virus pathogens including those causing poliomyelit ...	1986	3015442
antigen detection in the diagnosis of norwalk virus gastroenteritis.		1986	3016117
clinical associations of norwalk-like virus in the stools of children.	from among 1,360 stool specimens examined during the 19-month period from march 1982 to september 1983, small round-structured viruses, morphologically indistinguishable from the norwalk agent, were detected by electron microscopy in 42 specimens from 28 children. diarrhoea was mild, and vomiting, although frequently observed, was not an invariable feature. mild pyrexia occurred in three patients. many cases occurred some time after admission to the ward; this and other features suggested a hosp ...	1986	3016227
norwalk virus outbreak at a college campus.	an epidemic of nonbacterial gastroenteritis affected nearly 100 students at a college campus in jefferson county, alabama. the outbreak closely resembled food poisoning, since there was a rapid occurrence of multiple cases within a short period. vomiting occurred in 79% and diarrhea in 64%; fever was uncommon. we found a significant association between the illness and the eating of lettuce at a meal one day before the outbreak began. paired serologic specimens showed evidence of norwalk virus in ...	1986	3003923
bismuth subsalicylate in the treatment and prevention of diarrheal disease.	bismuth subsalicylate (bss) has been used for more than 80 years to treat gastrointestinal symptoms although little clinical evidence was available until recently to substantiate its value and possible mechanisms of action. bss 4.2 g given over 3 1/2 hours was shown to reduce the number of stools passed and favorably alter subjective symptoms in patients with traveler's diarrhea. bss has also been shown to have beneficial effects on chronic infantile diarrhea. a small but discernible effect has ...	1987	3308391
norwalk-like gastroenteritis epidemic in a toronto hospital.	an epidemic of gastroenteritis in a teaching hospital affected 57 patients and 69 staff over a 26-day period. the index case was a patient admitted with acute abdominal pain and diarrhea two days prior to the outbreak. the epidemic curve indicated person-to-person transmission. the incubation period, duration and types of symptoms were typical of norwalk gastroenteritis, and norwalk-like virus particles, serologically different from the prototype norwalk virus strain, were observed in 17 of 20 f ...	1987	3028187
antigenic relationships between human caliciviruses and norwalk virus.	we investigated antigenic relationships between human calicivirus (hcv) strains and norwalk virus by using immune electron microscopy (iem) and radioimmunoassay (ria). three serologically distinct hcv strains, uk1, uk2, and japan, were demonstrated by iem, as was evidence for two additional strains, uk3 and uk4. although hcv strains and norwalk virus were distinct by iem, 12 of 20 patients with gastroenteritis due to hcv uk4 and two of eight with gastroenteritis due to uk2 showed seroconversions ...	1987	2821127
two outbreaks of foodborne gastroenteritis caused by a small round structured virus: evidence of prolonged infectivity in a food handler.	in two outbreaks of diarrhoea and vomiting that were caused by a small round structured virus (srsv) that affected over 275 people, epidemiological and laboratory evidence showed that certain foods were the vehicles of infection and suggest that one of the chefs who prepared them may have been excreting this virus for a long time.	1987	2887841
novel agents of viral enteritis in humans.	considerable information has recently emerged regarding certain "groups" of novel viruses associated with gastroenteritis in humans. the viruses reviewed here are 20-35 nm in diameter and can be detected in the stools of acutely ill individuals with gastroenteritis. these viruses can be conveniently divided into four "groups": norwalk-like agents, caliciviruses, astroviruses, and other small round viruses. the evidence for the etiologic association of these agents with gastroenteritis varies fro ...	1987	3027199
foodborne snow mountain agent gastroenteritis in a school cafeteria.	in 1984, an outbreak of gastroenteritis occurred at a school with 1,860 students in brooklyn, ny. in a single-stage cluster sample of 375 students, 129 (34%) had illnesses that met our case definition of vomiting or diarrhea. the mean incubation period was 26 hours, and the mean illness duration was 24 hours. all case students had eaten in the cafeteria on at least one day between nov 13 and 16, compared with 174/214 (81%) noncase students (p = 10(-8), fisher exact test). foods implicated were f ...	1987	3029660
small round viruses: classification and role in food-borne infections.	since the first observation of norwalk virus in the electron microscope in 1972, many different small virus particles in the size range 20-40 nm have been described world-wide in association with outbreaks of gastroenteritis. progress characterizing these agents has been hampered by the relatively small numbers of particles present in clinical material and the lack of success in culturing them. although the relationship between some of these viruses remains confusing, a number of distinct groups ...	1987	3036438
the candidate caliciviruses.	the caliciviridae are a family of small (35-40 nm) rna viruses with a characteristic cupped morphology. they are unique in possessing only a single major structural polypeptide, of mr 60,000-71,000. the use of electron microscopy to investigate diarrhoeal diseases has revealed viral particles with the size and structure of the caliciviruses in the faeces of humans, domestic and farm animals, birds, reptiles and insects. in vivo experiments indicate that they are species specific and have confirm ...	1987	3036439
immunobiology of norwalk virus.	clinical immunity to norwalk virus in inoculated human volunteers appears to be unusual for gastroenteritis viruses, as certain individuals are repeatedly ill on long-term virus rechallenge and others remain persistently well. in these volunteers there is a paradoxical inverse correlation between the prechallenge serum (and jejunal fluid) norwalk antibody level (measured by radioimmunoassay) and resistance to illness, suggesting that non-immunological factors, perhaps genetic, may be important i ...	1987	3036440
viral hepatitis and gastroenteritis transmitted by shellfish and water.	the epidemiology and clinical presentation of water-borne viral diseases, including shellfish-associated viral illnesses, are discussed in this article. hepatitis a virus, non a-non b hepatitis and the agents of viral gastroenteritis, norwalk agent, snow mountain agent, rotavirus, the small round viruses, caliciviruses, and astroviruses are included. the technical problems associated with evaluating the viral contamination of water or shellfish are noted.	1987	2848882
small round structured viruses and persistence of infectivity in food handlers.		1987	2889072
norwalk virus antigen and antibody response in an adult volunteer study.	to better define the optimum timing of specimen collection and identify alternate ways to diagnose norwalk virus outbreaks, we looked at the timing of the antibody response and virus excretion in a human volunteer study. the norwalk virus antibody titers and antigen in stool specimens were examined by biotin-avidin immunoassay. our data suggest that in epidemic situations, convalescent-phase sera could be collected as soon as 13 days after the onset of illness and acute-phase sera could be colle ...	1987	2822766
risk factors for secondary transmission in households after a common-source outbreak of norwalk gastroenteritis.	in november 1984, a foodborne outbreak of norwalk gastroenteritis occurred in a k-12 public school in northern vermont. the outbreak offered an opportunity to systematically study in detail secondary transmission rates in households. eating salad at tuesday's school-sponsored thanksgiving banquet was associated with illness among students and staff members (p less than 0.025). seven of 11 serum pairs from ill persons showed a fourfold or greater rise in antibody titer to norwalk virus compared w ...	1987	2825520
leads from the mmwr. viral gastroenteritis--south dakota and new mexico.		1988	2828698
viral gastroenteritis--south dakota and new mexico.		1988	2828906
an electron microscopical investigation of faecal small round viruses.	a retrospective study of small round featureless viruses (srvs) initially identified by negative-staining electron microscopy of stool samples was performed. a variety of technique, including immunoelectron microscopy and caesium chloride gradient centrifugation, was applied in an attempt to classify further these viruses. over a four-year period, 64 srv-positive samples were reported (1.8% of the stool samples sent for electron microscopy and 6.2% of the total number of positive samples), of wh ...	1988	2832539
role of infected food handler in hotel outbreak of norwalk-like viral gastroenteritis: implications for control.	investigation of an outbreak of viral (norwalk-like) gastroenteritis amongst staff (40 cases), resident guests (over 70 cases), and persons attending functions (54 cases) at one hotel over 8 days suggested that the main vehicle of infection was cold foods prepared by a food handler during and after a mild gastrointestinal illness. he was excreting norwalk-like virus particles 48 hours after the illness. in addition, ill kitchen staff vomited in the kitchen area and may have contaminated surfaces ...	1988	2899729
outbreak of gastroenteritis in a home for the aged--ontario.		1988	2854008
gastrointestinal viral infections in homosexual men who were symptomatic and seropositive for human immunodeficiency virus.	gastrointestinal viruses, predominantly rotaviruses and adenoviruses, were detected by enzyme-linked immunosorbent assay, electron microscopy, or cell culture in greater than 50% of two groups of homosexual men with symptomatic human immunodeficiency virus (hiv) infection, who did (54%) or did not (50%) have diarrhea. lower detection rates were observed in hiv-seronegative (15%) and asymptomatic hiv-seropositive (16%) men. in the patients with diarrhea, 95% of the isolates of virus were found in ...	1988	2841379
solid-phase immune electron microscopy with human immunoglobulin m for serotyping of norwalk-like viruses.	a solid-phase immune electron microscopy method that uses protein a, goat anti-human immunoglobulin m (igm), and human serum is described. evaluation of the method with different immunoglobulin fractions showed that human igm constituted the major virus capture antibody. the method appeared to distinguish between two norwalk-like virus serotypes and demonstrated specific igm responses to these serotypes in infected individuals. further work is being carried out to define the relationship of thes ...	1988	2838506
update of viral gastroenteritis.		1988	2834120
production of a monoclonal antibody against the snow mountain agent of gastroenteritis by in vitro immunization of murine spleen cells.	the snow mountain agent (sma) is a 27- to 32-nm noncultivatable virus that causes acute gastroenteritis in humans. sma is morphologically similar to but immunologically distinct from the norwalk agent. sma has been partially purified from the stool of experimentally infected volunteers and contains a single structural protein of mr 62,000 as well as one or more non-virion-associated soluble proteins. further characterization of this important human pathogen and other norwalk-like viruses has bee ...	1988	2835775
25- to 30-nm virus particle associated with a hospital outbreak of acute gastroenteritis with evidence for airborne transmission.	between november 1 and 22, 1985, an outbreak of acute, nonbacterial gastroenteritis occurred in a 600-bed hospital in toronto, ontario, canada. illness in 635 of 2,379 (27%) staff was characterized by fatigue, nausea, diarrhea, and vomiting and had a median duration of 24-48 hours. the finding of virus-like particles measuring 25-30 nm in six stool specimens and low rates of seroresponse to norwalk virus (3/39) and snow mountain agent (1/6) suggest that a norwalk-like virus was responsible for t ...	1988	2835899
development of an enzyme immunoassay for the hawaii agent of viral gastroenteritis.	the hawaii agent is a norwalk-like virus of acute gastroenteritis in humans which is antigenically distinct from the prototype norwalk agent. we established a solid phase sandwich type microtiter enzyme immunoassay (eia) for hawaii antigen employing sera and stools from experimentally challenged volunteers as reagents. this assay detected the hawaii agent in stools from 3 of 8 volunteers who were ill after oral challenge with the hawaii agent, including one specimen which was positive to a dilut ...	1988	2851600
viral diarrhea.	viral diarrhea is a frequent, self-limited illness that may occur sporadically or in epidemic fashion. nosocomial outbreaks have been reported. rotavirus and norwalk virus are the two most important agents causing this disease. clinical illness is usually mild but may be quite severe in selected infants or elderly or debilitated persons. specific diagnosis has been advanced by the use of immunoassays. treatment is supportive, and most patients recover completely. good hygienic measures are effec ...	1988	3074122
an outbreak of acute infectious nonbacterial gastroenteritis in a high school in maryland.	an outbreak of acute infectious nonbacterial gastroenteritis (aing) occurred in a high school in maryland in 1984. thirty-six percent of students surveyed met the case definition of gastroenteritis, as did 24 percent of school employees. eating lunch in the cafeteria on january 30 was significantly associated with illness. after controlling for other food items consumed during the january 30 lunch, only the sandwiches were significantly associated with illness, but the source of the contaminatio ...	1989	2539604
prospects for development of a rotavirus vaccine against rotavirus diarrhea in infants and young children.	major advances have been made in elucidating the etiologic agents of severe infantile diarrhea, and it is clear that rotaviruses are the single most important etiologic agents. progress in the development of rotavirus vaccine candidates has also moved swiftly with the "jennerian" approach, in which a related live, attenuated rotavirus strain from a nonhuman host is used as the immunizing antigen. if this strategy is not effective against all rotavirus serotypes, reassortant rotaviruses hold grea ...	1989	2548276
viral enteritis in the 1980s: perspective, diagnosis and outlook for prevention.		1989	2549497
norwalk virus in norway: an outbreak of gastroenteritis studied by electron microscopy and radioimmunoassay.	an outbreak of acute gastroenteritis affected approximately half of 40 children staying at a holiday centre in southern norway. by direct electron microscopy norwalk-like viruses were demonstrated in 4/8 available stool specimens. no other pathogens were detected. antibody against these viruses was demonstrated by immune electron microscopy in all of 7 convalescent phase sera but in none of 11 acute phase sera collected. radioimmunoassay examination showed a rise in titre of norwalk virus antibo ...	1989	2555911
human viral gastroenteritis.	during the last 15 years, several different groups of fastidious viruses that are responsible for a large proportion of acute viral gastroenteritis cases have been discovered by the electron microscopic examination of stool specimens. this disease is one of the most prevalent and serious clinical syndromes seen around the world, especially in children. rotaviruses, in the family reoviridae, and fastidious fecal adenoviruses account for much of the viral gastroenteritis in infants and young child ...	1989	2644024
serum immunoglobulin a response to norwalk virus infection.	we describe the serum immunoglobulin a (iga) antibody response to norwalk virus infection in human volunteers and compare it with previously described igm and total antibody responses. whereas specific iga and igm peak within 2 weeks after onset of symptoms, titers of total blocking antibody continue to rise, implying mediation by igg antibody.	1989	2546980
foodborne gastroenteritis due to norwalk virus in a winnipeg hotel.	within 1 week four separate incidents of gastroenteritis presumed to be foodborne were reported by guests of a winnipeg hotel. investigation revealed poor food-handling practices and illness among the kitchen staff. elevated bacterial counts and escherichia coli were found in 15 of 24 samples of food tested, and staphylococcus aureus was isolated from 2 pastry samples. culture of 14 stool samples for bacteria yielded clostridium perfringens in 1 sample from a staff member and coagulase-positive ...	1989	2541881
viral gastroenteritis aboard a cruise ship.	a 32-nm small round structured virus (srsv), possibly related to the snow mountain agent (sma), was implicated as the cause of recurrent outbreaks of gastroenteritis on a cruise ship. there was no identifiable relation to food or water consumption, but the risk of gastroenteritis among passengers who had shared toilet facilities was twice that of those who had a private bathroom and the rate of illness was related to the number of passengers sharing a communal restroom (ie, with one or more toil ...	1989	2571872
role of norwalk virus in two foodborne outbreaks of gastroenteritis: definitive virus association.	two separate food-associated outbreaks of gastroenteritis occurred among erie county, new york residents in june 1986. in one outbreak, cases of illness were estimated to have occurred in 50% of the approximately 700 persons in 13 groups who ate at an out-of-county restaurant during a seven-day period, and, in the second outbreak, illness occurred in 26 (30%) of 87 persons who attended a graduation party held in a private home. laboratory investigation included serology (blocking radioimmunoassa ...	1989	2535916
two institutional outbreaks of norwalk-like gastroenteritis--ontario.		1989	2544302
development and evaluation of an igm capture enzyme immunoassay for diagnosis of recent norwalk virus infection.	a capture enzyme immunoassay specific for norwalk igm class antibody was developed. the assay was moderately sensitive, identifying 33/53 (62%) of patients with naturally acquired norwalk virus infection and 17/18 (94%) of experimentally infected volunteers. the assay was also specific for igm class antibody and acute norwalk virus infection and results were generally reproducible. a specific igm response correlated with seroconversion by total antibody blocking assay and occurred independently ...	1989	2547819
small round structured viruses and their spread.		1989	2563823
human, small round structured viruses, caliciviruses and astroviruses.	epidemiological studies on srsvs, human calicivirus and astroviruses have been limited by the problems of establishing them in cell culture and the inability to transmit them to animals or to use strains from animals as a source of antigen for diagnostic tests. the use of em and the subsequent development of rias and eias in a few research centres has shown that they are a cause of outbreaks and sporadic cases of diarrhoea and vomiting. srsvs have increasingly been recognized as a major cause of ...	1990	1962728
diagnosis of astrovirus gastroenteritis by antigen detection with monoclonal antibodies.	an enzyme-linked immunosorbent assay (elisa), based on monoclonal antibodies to the astrovirus group antigen, was designed for the detection of astroviruses in stools of patients with gastroenteritis. compared to immune electron microscopy used as the standard test, the sensitivity of the astrovirus elisa was 91% (31/34) and the specificity was 96% (54/56). all five of the known astrovirus serotypes could be detected in 16 samples on which serotyping was done. in tests on 155 stools containing o ...	1990	2105359
foodborne gastroenteritis due to norwalk virus in a winnipeg hotel.		1990	2154305
three serotypes of norwalk-like virus demonstrated by solid-phase immune electron microscopy.	solid phase immune electron microscopy (spiem) was used to investigate the serological differences between norwalk-like virus (nlv) strains from five different outbreaks within the united kingdom. the existence of two previously demonstrated serotypes, lewis et al. (journal of clinical microbiology 26:938-942, 1988), was confirmed by the use of whole convalescent sera and purified igm. a third serotype was found to be the agent of two recent hospital outbreaks and could similarly be typed by use ...	1990	2154547
viral agents of gastroenteritis. public health importance and outbreak management.	each year, infectious gastroenteritis causes greater than 210,000 children in the united states to be hospitalized and 4-10 million children to die worldwide. since the mid-1970s, knowledge has increased dramatically concerning the viral agents that are responsible for much of this public health burden. rotavirus, the most common cause of diarrhea among children, infects virtually every child in the united states by the age of 4 years and causes potentially lethal dehydration in 0.75% of childre ...	1990	2157945
norwalk agent comes of age.		1990	2160504
foodborne gastroenteritis due to norwalk virus in a winnipeg hotel.		1990	2161705
occurrence of norwalk virus infections among adults in mexico.	norwalk virus infection was sought in 48 us, 49 puerto rican, and 27 mexican adults attending medical school in guadalajara (mexico) who were enrolled in a 2-year longitudinal study. serum specimens were collected quarterly and as acute- and convalescent-phase samples around episodes of gastroenteritis. the reciprocal norwalk virus geometric mean titer (gmt) for puerto rican students (567) was significantly higher than that of the us students overall (294; p less than .001) and for four of nine ...	1990	2165112
norwalk-like gastroenteritis epidemic in a teaching hospital--quebec.		1990	2170034
large outbreak of foodborne norwalk-type viral gastroenteritis in a district general hospital--united kingdom.		1990	2170035
epidemiology of travelers' diarrhea and relative importance of various pathogens.	each year 12 million persons travel from an industrialized country to a developing country in the tropics or subtropics. these travelers experience a high rate of diarrhea caused by a wide variety of enteric pathogens acquired by ingestion of contaminated food or water. one or more pathogens can be found in the stool of a majority of ill individuals. enterotoxigenic escherichia coli generally are the most frequently identified pathogens, having been found in a median of 42% of travelers' diarrhe ...	1990	2406860
antigenic relatedness among the norwalk-like agents by serum antibody rises.	the norwalk, snow mountain (sma), and hawaii agents are etiologically associated with separate outbreaks of acute viral gastroenteritis. previous cross-challenge of volunteers, immune electron microscopy, and/or enzyme-immunoassay analysis suggested that these agents are antigenically distinct. we examined paired sera from human volunteers challenged with these agents for the presence of homologous and heterologous serum antibody titer rises to the agents. two-way cross-reactions occurred betwee ...	1990	1704048
multiple-challenge study of host susceptibility to norwalk gastroenteritis in us adults.	in a multiple-challenge study of us adult volunteers with low or high levels of serum antibody to norwalk virus, norwalk inoculum 8fiia was administered to 42 subjects, 22 were challenged 6 months later, and 19 received a third challenge after 6 more months. all 12 with high (greater than or equal to 1:200) but only 19 of 30 with low (less than 1:100) prechallenge titers experienced illness or a fourfold increase in titer after the first challenge (p less than .025). only 4 of those challenged t ...	1990	2153184
pathogenesis of gut virus infection.	in summary, the pathogenesis of many gut virus infections remains uncertain. however, human and animal studies indicate that the majority of gut viruses infect villous enterocytes. viruses appear to have different affinities for enterocytes at different sites on the villus. infection of enterocytes leads to cell death, extrusion into the lumen, and villous atrophy when the rate of cell production in the crypts cannot keep pace with the rate of enterocyte loss. this results in a reduced surface a ...	1990	1962725
small round structured viruses: an important infection control problem?		1990	2172362
an outbreak of acute gastroenteritis caused by a small round structured virus in a geriatric convalescent facility.	an outbreak of acute gastroenteritis (age) occurred in a 201-bed geriatric convalescent facility in los angeles county during december 1988 through january 1989. the attack rate was 55% among residents and 25% among employees. illnesses were characterized by vomiting and diarrhea to a lesser extent, and the absence of fever. bacterial and parasitic tests in a sample of patients were negative. a 27 nm small round structured virus (srsv) was identified in one of 30 stools studied by immune electro ...	1990	2172363
[gastroenteritis caused by norwalk-group viruses].		1990	2158706
norwalk virus genome cloning and characterization.	major epidemic outbreaks of acute gastroenteritis result from infections with norwalk or norwalk-like viruses. virus purified from stool specimens of volunteers experimentally infected with norwalk virus was used to construct recombinant complementary dna (cdna) and derive clones representing most of the viral genome. the specificity of the clones was shown by their hybridization with post- (but not pre-) infection stool samples from volunteers infected with norwalk virus and with purified norwa ...	1990	2177224
the isolation and characterization of a norwalk virus-specific cdna.	norwalk virus, an important cause of epidemic, acute, nonbacterial gastroenteritis in adults and children, has eluded adaptation to tissue culture, the development of an animal model, and molecular cloning. in this study, a portion of the norwalk viral genome encoding an immunoreactive region was cloned from very small quantities of infected stool using sequence-independent single primer amplification. six overlapping complementary dna (cdna) clones were isolated by immunologic screening. the ex ...	1991	2010555
diarrheal disease during operation desert shield.	under combat conditions infectious disease can become a major threat to military forces. during operation desert shield, there were numerous outbreaks of diarrhea among the u.s. forces. to evaluate the causes of and risk factors for diarrheal disease, we collected clinical and epidemiologic data from u.s. troops stationed in northeastern saudi arabia.	1991	1656260
[food poisoning outbreak probably of viral etiology caused by norwalk virus].	in may 1989, a foodborne outbreak of acute gastroenteritis was identified in a state school in adzaneta, castellón. a dtudy was undertaken to describe it, investigate its causes, and recommend adequate control measures. sixteen children and 2 teachers were affected (attack rate: 28.57%). kaplan and cols clinical and epidemiological criteria for norwalk-like virus as the responsible agent were present. the probable origin of the outbreak was a foodhandler who was already ill beforehand. the exami ...	1991	1664422
detection of norwalk-like virus and specific antibody by immune-electron microscopy with colloidal gold immune complexes.	direct electron-microscopy (dem), immune electron microscopy (iem) and four different procedures of immune electron microscopy with colloidal gold immune complexes were evaluated for the detection of norwalk-like virus and specific antibody. a solid-phase immune electron microscopy with colloidal gold immune complexes-triple layer method (spiemgic-tlm) is developed for screening patients' specimens for the detection of norwalk-like virus and its specific antibody. the method demonstrates low non ...	1991	1667789
[food-borne outbreaks of gastroenteritis caused by small round structured viruses. 1. four outbreaks of gastroenteritis associated with oyster consumption].	between december 9, 1988 and january 28, 1989, there were four outbreaks of acute gastroenteritis in saitama prefecture. eighty-two of 123 persons (67%) attending four banquets in restaurants became ill: 44 cases attending three banquets were related to eating raw oysters, and 38 attending one banquet to eating sashimi. the most common symptoms were nausea, diarrhea, abdominal cramps, and vomiting. average incubation periods were 29 to 32 hours long. bacteriologic analysis of stool specimens did ...	1991	1662251
norwalk agent and other small-round structured viruses in the u.k.		1991	1661318
gastroenteritis associated with shellfish.		1991	1669888
a large nontypical outbreak of norwalk virus. gastroenteritis associated with exposing celery to nonpotable water and with citrobacter freundii.	the us air force academy experienced a point-source outbreak of gastroenteritis originally believed to be caused by salmonella. the overall attack rate was 48% among approximately 3000 cadets and staff. food-specific attack rates implicated chicken salad. the odds ratio for chicken salad consumption in ill cadets was 10.7 (95% confidence interval: 8.2; 13.8). the celery component had been exposed to nonpotable water. citrobacter freundii were statistically associated with consumption of the susp ...	1991	1660704
isolation of cytopathic small round viruses with bs-c-1 cells from patients with gastroenteritis.	fecal extracts from 12 subjects in outbreaks of oyster-associated nonbacterial gastroenteritis were inoculated with bs-c-1 cells for isolation of the causative viruses. cytopathic agents were isolated from 3 patients. no cross-neutralizing reactions were observed between the isolates and prototypes of human enteroviruses. the isolates were approximately 30 nm in diameter and had a distinct ultrastructure resembling that of astroviruses. four polypeptide bands with molecular sizes of 42, 28, 27, ...	1991	1658159
virus survival in the environment.	viruses pass into the environment from clinically ill or carrier hosts; although they do not replicate outside living animals or people, they are maintained and transported to susceptible hosts. population concentrations and movement, both animal and human, have been steadily increasing in this century, enhancing transmission of respiratory and enteric viruses and compounding the difficulty of preventing environmental transmission. studies on environmental survival factors of viruses have been m ...	1991	1782426
rabbit hemorrhagic disease virus--molecular cloning and nucleotide sequencing of a calicivirus genome.	the rna genome of rabbit hemorrhagic disease virus (rhdv) was molecularly cloned. the 5' terminal sequence of the genomic rna was determined after pcr amplification of a g-tailed first strand cdna template. the cloned cdna allowed determination of the first complete caliciviral sequence encompassing 7437 nucleotides without poly(a) tail. the rhdv genome contains one long open reading frame of 2344 codons which in the 5' region encodes the nonstructural proteins. sequence comparison studies revea ...	1991	1840711
a multistate outbreak of norwalk virus gastroenteritis associated with consumption of commercial ice.	between 19 and 27 september 1987, a cluster of outbreaks of gastrointestinal illness occurred among persons who had attended a museum fund-raiser in wilmington, delaware and an intercollegiate football game in philadelphia. a survey of four groups attending these events showed that 31% (191/614) became ill. altogether, those who consumed ice were 12 times more likely to experience either vomiting or diarrhea than those who did not (attack rate, 55% vs. 4%, p less than .001). ice consumed at the ...	1991	1658158
viral gastroenteritis.		1991	1647494
enteric infections associated with exposure to animals or animal products.	the epidemiology and clinical presentation of enteric infections are discussed in this article. these include bacterial, viral, and parasitic illnesses, and are associated with the increasing popularity of drinking unpasteurized milk; eating raw fish and shellfish; consuming undercooked pork, poultry, and eggs; and having contact with pets. salmonella, campylobacter jejuni, vibrio, yersinia, aeromonas, edwardsiella, hepatitis a virus, norwalk virus, anisakis, eustrongylides, diphyllobothrium, na ...	1991	1955706
infection with small round structured viruses: england and wales 1981-1990.	infection with small round structured viruses (srsv) usually causes an acute, but short-lived, attack of gastroenteritis in which vomiting is a prominent feature. most documented outbreaks have occurred in institutional and catering establishments and infected food handlers are often implicated. reports of srsv infection have risen substantially during the last decade partly due to an increase in the number of laboratories able to examine samples for this organism. ascertainment is likely to rem ...	1991	1669758
what did our patients eat?		1991	1669789
waterborne outbreak of norwalk virus gastroenteritis at a southwest us resort: role of geological formations in contamination of well water.	from april 17 to may 1, 1989, gastroenteritis developed in about 900 people during a visit to a new resort in arizona, usa. of 240 guests surveyed, 110 had a gastrointestinal illness that was significantly associated with the drinking of tap water from the resort's well (relative risk = 16.1, 95% confidence interval 14.5 to 17.8) and this risk increased significantly with the number of glasses of water consumed (p less than 0.005). three of seven paired sera tested for antibodies to the norwalk ...	1991	1673747
[food-borne outbreak of gastroenteritis caused by small round structured virus. 2. an outbreak associated with bakery product consumption].	in december 1989, an outbreak of gastroenteritis associated with cake consumption occurred in a day-care center with 60 children and 12 staff in saitama prefecture. children were served cakes at the christmas party held in the day-care center and ate them with their families. thirty-three of the 59 children (56%), 16 of the 74 families (22%) and 1 of the 10 staff (10%) eating the cakes became ill. illness consisted primarily of nausea, vomiting, diarrhea and fever; the median incubation period w ...	1991	1664441
detection of norwalk virus in stool by polymerase chain reaction.	a method of reverse transcription (rt) and polymerase chain reaction (pcr) for the detection of norwalk virus in human stools was developed. a cationic detergent, cetyltrimethylammonium bromide, was found to effectively remove from stool extracts factors that inhibit the rt-pcr assay. the specificities of the tests were shown by hybridization of the amplified dna with norwalk virus-specific cdna probes and a consistent correlation between virus detection in stools and infection of volunteers. rt ...	1992	1383265
[outbreaks of acute gastroenteritis caused by small round structured viruses in tokyo].	of 34 non-bacterial gastroenteritis outbreaks which occurred at day-care centers, kindergartens, elementary and secondary schools in tokyo during the period from february 1985 to june 1991, 28 outbreaks from which small round structured viruses (srsv) were detected in the patients' stool specimens by electron microscopy were subjected to an epidemiological investigation. the outbreaks tended to occur frequently in the cold season; twenty-two (79%) of these outbreaks from november through april. ...	1992	1331265
expression, self-assembly, and antigenicity of the norwalk virus capsid protein.	norwalk virus capsid protein was produced by expression of the second and third open reading frames of the norwalk virus genome, using a cell-free translation system and baculovirus recombinants. analysis of the expressed products showed that the second open reading frame encodes a protein with an apparent molecular weight of 58,000 (58k protein) and that this protein self-assembles to form empty viruslike particles similar to native capsids in size and appearance. the antigenicity of these part ...	1992	1328679
viral gastrointestinal infections.	numerous disease-causing viruses of the gastrointestinal tract have been described. the diseases that they induce range from subclinical to fatal gastrointestinal or systemic organ infection. recent advances in molecular biology and virus culture techniques, as well as improvements in animal models of these infections, have increased our understanding of pathologic processes associated with these viruses. although our overall understanding of these viruses has improved to the extent that many mo ...	1992	1324891
[viral diarrheas].	it is now well known that several viruses are responsible for acute diarrhoea or gastroenteritis in both children and adults. these viruses are difficult to identify since most of them cannot be isolated by stool cultures on cells. the reality of proven reinfection by some of these organisms is not always clearly understood, even though the existence of several serotypes in the same group (notably rotavirus) can be blamed, and this explains why vaccines are difficult to develop.	1992	1313558
a serosurvey of pathogens associated with shellfish: prevalence of antibodies to vibrio species and norwalk virus in the chesapeake bay region.	recent concerns regarding the safety of shellfish consumption have focused on the risk posed by naturally occurring marine bacteria such as vibrio species and by viruses such as norwalk and related agents. despite the widespread environmental presence of vibrio species in the chesapeake bay, the rate of reported infections remains low; there have also been no reports of major norwalk outbreaks associated with shellfish in this area. as infections with these agents may not always be recognized be ...	1992	1312771
the diagnosis of srsv infection.		1992	1284950
demonstration of low molecular weight polypeptides associated with small, round-structured viruses by western immunoblot analysis.	small, round-structured viruses (srsv) were detected in 14 of 300 fecal specimens obtained from patients with acute gastroenteritis by electron microscopy. these srsv strains were morphologically indistinguishable from one another. while 11 of these strains had a single usual major structural protein with molecular weight of 63,000 (63k) daltons (p63), interestingly, three strains possessed a single major structural protein with molecular weight of 33k daltons (p33). treatments of p63-srsv with ...	1992	1282654
detection of norwalk virus in stool specimens by reverse transcriptase-polymerase chain reaction and nonradioactive oligoprobes.	a reverse transcriptase (rt)-polymerase chain reaction (pcr)-oligoprobe (op), or rt-pcr-op, method was developed for the detection of the norwalk virus, which causes acute, epidemic gastroenteritis, in stool specimens. the norwalk virus genome regions encoding the following two proteins were amplified by rt-pcr: the rna polymerase (260-bp product) and a putative immunogenic protein (224-bp product). the resulting dna fragments (amplicons) were hybridized to a digoxigenin-labeled internal op spec ...	1992	1280649
pilot study of an extended range of potential etiologic agents of diarrhea in the israel defense forces.		1992	1310297
small round structured viruses (srsv).		1993	7506612
detection of antibody to recombinant norwalk virus antigen in specimens from outbreaks of gastroenteritis.	norwalk virus and other small round-structured viruses are commonly associated with outbreaks of gastroenteritis. we used a recently described recombinant-expressed norwalk virus (rnv) capsid protein in enzyme immunoassays to quantitatively measure immunoglobulin g (igg) and iga to norwalk virus in serum pairs from patients involved in outbreaks of gastroenteritis. the outbreaks previously were classified, on the basis of the results of a blocking antibody assay, as norwalk virus negative, serol ...	1993	8263169
small, round-structured viruses (srsvs) associated with acute gastroenteritis outbreaks in gifu, japan.	two outbreaks of non-bacterial gastroenteritis occurred in gifu prefecture in january 1989 and in january 1991. both outbreaks were closely related to the consumption of raw oysters, and showed similar clinical features. small, round-structured virus particles were found in patient stools in both outbreaks by electron microscopy. the role of these particles as the causative agents of the outbreaks were strongly suggested by immune electron microscopy and/or western-blotting immunoassay. when com ...	1993	8133807
prevalence of newly isolated, cytopathic small round virus (aichi strain) in japan.	cytopathic small round virus (aichi strain), isolated from a patient with oyster-associated gastroenteritis, showed no reaction in the polymerase chain reaction method for enteroviruses or in the enzyme-linked immunosorbent assay (elisa) for the five serotypes of astroviruses. our elisa was sensitive in detecting the aichi strain antigen in stool samples, but there was no reaction in this elisa with any non-aichi strains of enteric viruses, with such origins as enterovirus, rotavirus, norwalk vi ...	1993	8263178
two successive outbreaks of srsv-associated gastroenteritis in south africa.	two successive outbreaks of gastroenteritis in south africa were investigated to identify the aetiological agents. some patients were involved in both outbreaks. enteropathogenic bacteria or parasites were not evident in either outbreak. small round structured viruses (srsvs) were demonstrated in both outbreaks by direct electron microscopy. srsv uk3/hawaii virus was identified by immune electron microscopy as the causative agent in the first outbreak. using new recombinant norwalk virus (rnv) i ...	1993	8228932
comparison of the reactivities of baculovirus-expressed recombinant norwalk virus capsid antigen with those of the native norwalk virus antigen in serologic assays and some epidemiologic observations.	since the discovery of the norwalk virus (nv) by immune electron microscopy (iem) in 1972, serologic studies with this virus have relied on particle-positive fecal material from infected volunteers as the source of antigen because it has not been possible to propagate this virus in cell culture. however, the recent cloning of the nv (strain 8fiia) genome and expression of the capsid protein in a baculovirus system to form "virus-like particles" has provided a consistent source of antigen (design ...	1993	8396590
norwalk-like viruses: demonstration of genomic diversity by polymerase chain reaction.	a reverse transcription-polymerase chain reaction (rt-pcr) amplification procedure was developed for the detection of norwalk-like viruses in fecal specimens. ninety-nine fecal specimens collected in the united kingdom and containing small round-structured virus particles as determined by electron microscopy were tested. they came from 50 outbreaks and 16 sporadic cases of viral gastroenteritis. rt-pcr products of the appropriate size for norwalk virus rna were detected in 15 specimens from thre ...	1993	8263187
efficacy of a recombinant norwalk virus protein enzyme immunoassay for the diagnosis of infections with norwalk virus and other human "candidate" caliciviruses.	a recombinant norwalk virus antigen enzyme immunoassay (rnv eia) for the detection fo norwalk virus (nv) antibodies was evaluated using sera from volunteers and patients infected with norwalk, hawaii, snow mountain agent, small round structured viruses (srsv), and human calicivirus (hucv) strains. the results for nv antibodies correlated well with previous results obtained using a nv radioimmunoassay. the test rnv eia was found to be highly specific for nv. the results of tests on sera obtained ...	1993	8263497