Publications

acute viral enteritis and exacerbations of inflammatory bowel disease.	in order to determine whether or not acute viral gastroenteritis predisposes to exacerbations of inflammatory bowel disease, patients with crohn's disease and ulcerative colitis were observed longitudinally. assessment of disease activity was correlated with evidence for viral infection by serology and stool antigen testing. disease exacerbations were rarely associated with rotavirus, norwalk agent, or adenovirus infection, primarily because these infection rates were very low. however, the few ...	1982	6290307
viral diseases: infections of the gastrointestinal tract.	in the 1970s investigations generated a remarkable amount of information on the viruses responsible for acute gastroenteritis. the two viruses responsible for most cases occur in epidemiologically distinct clinical forms. although occasionally epidemic, rotavirus infections are usually sporadic and primarily affect infants and young children. this illness is characterized by severe diarrhea commonly lasting five to eight days and frequently associated with upper respiratory tract symptoms, fever ...	1982	6290133
potassium tartrate-glycerol as a density gradient substrate for separation of small, round viruses from human feces.	cesium chloride density gradients are frequently used for virus concentration or purification in the preparation of human feces for examination by electron microscopy, disruption of some of the fecal viruses occurs if they are pelleted from the density gradient in an additional concentration step. this report highlights an important limitation imposed by the use of cesium chloride as a density gradient substrate in attempting to recover small, round, virus-like particles from feces and suggests ...	1982	6288767
immunoglobulin m responses to the norwalk virus of gastroenteritis.	eighty-seven serum specimens from 20 human subjects experimentally inoculated one or more times with norwalk virus were quantitatively examined for virus-specific immunoglobulin m (igm). a sensitive and specific radioimmunoassay for anti-norwalk virus blocking activity was applied to whole serum and to separate igm and igg fractions obtained by sucrose density gradient ultracentrifugation. the peak igm response occurred at about 2 weeks after illness, but igm was detectable at lower titers for u ...	1982	6288563
the electron microscopical and physical characteristics of small round human fecal viruses: an interim scheme for classification.	many of the small round human fecal viruses implicated in outbreaks of nonbacterial gastroenteritis have been collected together and examined under the electron microscope. negatively stained preparations without the addition of antibody were used so that the surface morphology of the virus particles remained clearly visible. it was apparent that several viruses, previously thought to be simply antigenic variants within the norwalk group of viruses, show distinct morphological differences and qu ...	1982	6286860
gastroenteritis due to norwalk virus: an outbreak associated with a municipal water system.	an outbreak of gastroenteritis lasting for one week in august 1980 affected approximately 1,500 persons in a community in northern georgia. investigation included a telephone survey of the community, a survey of textile plant employees and junior high and high school students and staff, and a neighborhood door-to-door survey. an association between gastrointestinal illness and consumption of drinking water was shown for community residents, students, and school staff. attack rates (0-68%) determ ...	1982	6286788
detection by immune electron microscopy of the snow mountain agent of acute viral gastroenteritis.	an extensive outbreak of acute gastroenteritis of unknown etiology occurred at snow mountain, colorado, in december 1976. virus-like particles, 27 nm in diameter, were observed by electron microscopy in two of five stool specimens from individuals in the outbreak. oral administration of a filtrate from one of the specimens induced disease in nine of 12 normal volunteers. experimentally induced illness was similar to that observed during the outbreak. stool specimens examined by immune electron m ...	1982	6286787
antibodies to gastroenteritis viruses in cystic fibrosis patients.	infectivity of certain enteric viruses including rotavirus is profoundly affected by proteolytic enzymes. to test whether cystic fibrosis patients, possessing chronically decreased levels of pancreatic enzymes, show altered susceptibility to gastroenteritis viruses, we examined sera from patients and controls for antibodies to two major pathogens. in cystic fibrosis patients, normal rotavirus antibody levels were found and norwalk virus antibody prevalence was unchanged.	1982	6284870
epidemiology of norwalk gastroenteritis and the role of norwalk virus in outbreaks of acute nonbacterial gastroenteritis.	outbreaks of norwalk gastroenteritis, which may involve persons of all ages, occur during all seasons and in various locations. waterborne, foodborne, and person-to-person modes of transmission have been described, and secondary person-to-person transmission is common. outbreaks generally end in about 1 week; longer outbreaks occur only when new groups of susceptible persons are introduced, usually in the setting of a persistent common source of infection. the illness is generally mild and chara ...	1982	6283977
diarrhea due to norwalk virus in families.		1982	6282989
[norwalk-like viruses as probable etiological agents in the epidemic of non-bacterial gastroenteritis (author's transl)].		1982	6282470
[viral diarrhea].	viruses are one of the most frequent causes of acute infectious gastroenteritis. thus, rotaviruses are responsible for 40-60%--and in winter sometimes for over 90% - of diarrhoea in infants. these viruses may also cause disease in adults, but small viruses of a size of about 27 nm, such as the norwalk agent, play a much more important role. several other non-cultivable viruses such as adeno-, calici- and astroviruses have been implicated as a cause of infectious diarrhoea. knowledge of rotavirus ...	1982	6281877
viral gastroenteritis.		1982	6281591
acquisition of serum antibody to norwalk virus and rotavirus and relation to diarrhea in a longitudinal study of young children in rural bangladesh.	serum antibodies to norwalk virus and to rotavirus were measured during longitudinal studies of infectious diseases and nutrition in rural bangladesh. initially, the prevalence of antibody to norwalk virus was 7% in children younger than six months and increased to 80% in children two to five years of age. the incidence of titer increases was highest in one- and two-year-olds and in children who had low or undetectable levels of antibody. some norwalk virus infections appeared to result in diarr ...	1982	6279734
norwalk virus gastroenteritis following raw oyster consumption.	in january, 1980, six out of 13 persons (46%) attending a party in a small northwest florida town near the gulf of mexico became ill with norwalk virus gastroenteritis after eating raw oysters. symptoms experienced by the ill persons were principally nausea (100%), vomiting (83%) and diarrhea (50%) and were of brief duration. the symptom complex and epidemiology of norwalk virus infection closely resemble the gastrointestinal illness commonly referred to as the 24-hour intestinal flu or "stomach ...	1982	6278928
[variation of diarrhea viruses detected in japan with special reference to spherical viruses other than rotaviruses (author's transl)].		1981	6278755
foodborne norwalk virus.	on december 6, 1979, three luncheon banquets were served in a new jersey restaurant. thirty-eight of 41 members (92.7%) of the first group became ill as did 25 of 31 members (80.6%) of the second group. none of 12 members of the third group were ill. illness consisted primarily of diarrhea (76%), nausea, (73%), vomiting (67%), cramps (46%) and fever (18%); the median incubation period was 31 hours and median duration 24 hours. the same foods were served to all three groups, except that cole slaw ...	1982	6277186
norwalk virus enteric illness acquired by swimming exposure.	in an epidemic of gastrointestinal illness strongly associated with swimming at a recreational park in macomb county, michigan, in july, 1979, the authors demonstrated the value of serologic testing to detect norwalk virus infection. rises in antibody titer to norwalk virus were noted in all 11 individuals tested. electron microscopy on stools from 20 ill individuals revealed only one with norwalk virus-like particles. this particle was shown by radioimmunoassay and immune electron microscopy no ...	1982	6277185
norwalk gastrointestinal illness: an outbreak associated with swimming in a recreational lake and secondary person-to-person transmission.	an outbreak of gastrointestinal illness in which headache, low grade fever and myalgia were common symptoms occurred among persons who visited a recreational park in macomb county, michigan, on july 13-16, 1979. the temporal clustering of onsets of 121 persons who were the first in their households to become ill suggested an incubation period ranging from 4-77 hours. a history of swimming in the park's lake was elicited with significantly greater frequency from these persons than from park visit ...	1982	6277184
lymphocytotoxic and microbial antibodies in crohn's disease and matched controls.	patients with crohn's disease and age, sex and seasonally matched healthy controls were studied for cold lymphocytotoxic and a variety of microbial antibodies. lymphocytotoxic antibody titers were increased significantly in the crohn's patients compared to controls, but did not correlate with any of the microbial titers. antibodies to a pseudomonas-like bacterium and bacteroides vulgatus were also increased in the patients, but titers to chlamydia trachomatis, rotavirus and norwalk virus were no ...	1981	6275790
waterborne gastroenteritis due to the norwalk agent: clinical and epidemiologic investigation.	an outbreak of gastroenteritis occurred at a pennsylvania summer camp in july 1978. symptoms included abdominal pain (81 per cent), nausea (72 per cent), and vomiting (53 per cent); upper respiratory infection symptoms occurred in 35 per cent of the campers. illness was associated with consumption of five or more glasses of water or water-containing beverages. stool cultures from affected persons were negative for bacterial pathogens; however, a fourfold or greater rise to the norwalk agent was ...	1982	6274208
travelers' diarrhea in panamanian tourists in mexico.	to determine whether residents of developing countries are unlikely to acquire travelers' diarrhea, 64 panamanians of widely divergent socioeconomic strata were studied during a 15-day tour through mexico. twenty-three (36%) tourists experienced 27 episodes of travelers' diarrhea that were caused by seven different pathogens. the most commonly identified etiologic agents were rotavirus (26%), norwalk virus (15%), and campylobacter fetus (11%), whereas enterotoxigenic escherichia coli was not fre ...	1981	6273474
norwalk-related viral gastroenteritis due to contaminated drinking water.	an explosive outbreak of gastrointestinal illness clinically compatible with infection by an agent serologically related to norwalk virus agent occurred in an elementary school in may 1978. seroconversion by radioimmunoassay to the norwalk antigen was noted in two of three ill persons, but no viral particles were identified in stool. illness developed in 72% of students and teachers at the school, and 32% of household contacts of these ill persons. of household contacts of persons exposed at sch ...	1981	6272571
aetiology of viral gastroenteritis: a review.	over the past seven to eight years, several virus groups have been shown to be associated with gastroenteritis. they are adenoviruses, astroviruses, caliciviruses, coronaviruses. norwalk-like viruses and rotaviruses. in infants and young children, rotaviruses are the single most important aetiological agents of acute gastroenteritis in terms of numbers of cases and also of patients requiring admission to hospital. in older children and adults, the aetiology is less clear, but the present state o ...	1981	6272071
a prospective study of rotavirus infection in infants and young children.	diarrhea in neonates, followed as a cohort, and their families was studied prospectively. the families were followed for an average of 16.3 months. stool and serum specimens were obtained at least every three months. stool specimens were examined for viruses by electron microscopy and cultured for enteropathogens, and serum specimens were tested for antibodies to rotavirus and norwalk virus. during the study, 237 episodes of gastroenteritis were observed in 104 infants and their 62 siblings. rot ...	1981	6268713
enzyme-linked immunosorbent assay for the detection and identification of coxsackie b antigen in tissue cultures and clinical specimens.	an enzyme-linked immunosorbent assay (elisa) has been developed for the identification of coxsackie b antigens. this assay was capable of identifying and distinguishing all six coxsackie b serotypes at concentrations one hundredfold to ten thousandfold less than could be detected by complement fixation (cf) systems. in addition, the coxsackie b elisa correctly identified the presence of coxsackie b antigen in 19 of 21 tissue culture fluids and five of nine rectal swab specimens. two additional r ...	1980	6262456
protective effect of anticholinergic drugs and psyllium in a nosocomial outbreak of norwalk gastroenteritis.	an outbreak of norwalk agent gastroenteritis occurred in a chronic-care hospital in tennessee in april 1981. fifty-five per cent of the elderly psychiatric patients and 61 per cent of the nursing employees on one floor became ill. infection was most likely to have spread from patient-to-patient by nursing employees. certain chronic medications seemed to protect patients from symptomatic infection. anticholinergic drugs appeared to mask the symptoms of this disease; psyllium ('metamucil') may hav ...	1983	6198366
[viral diarrhea].		1982	6191463
norwalk virus and rotavirus in travellers' diarrhoea in mexico.		1982	6119475
[diarrhea in young calves. 6. determination of the pathogenicity of a bovine coronavirus and an unidentified icosahedral virus].		1984	6099109
[viral etiology of gastroenteritis].		1984	6097282
[epidemiologic and electron microscopic study of viral gastroenteritis in kagawa prefecture, japan, revealed three distinct causative agent groups].		1984	6096456
viral diarrhoeas.		1984	6096438
serological responses among teenagers after natural exposure to norwalk virus.	twenty-one teenagers exposed to a contaminated water supply during an outbreak of gastroenteritis were tested for seroconversion to norwalk virus. serum specimens were collected within 72 hr of exposure and four weeks later. each of the 11 individuals who developed symptoms and five of the 10 who remained well had a whole-antibody response in serum. none of the remaining five teenagers became ill or seroconverted. neither seroconversion nor susceptibility to illness was associated with an absenc ...	1984	6092484
viral gastroenteritis.		1984	6092272
[norwalk virus and acute gastroenteritis].		1984	6088049
food borne infection by a norwalk like virus (small round structured virus).	two outbreaks of gastrointestinal illness with identical symptoms occurred in parties attending banquets on consecutive evenings at a large hotel. the illness was typical of epidemic winter vomiting disease. small round structured viruses resembling those seen in the norwalk ohio outbreak were identified by electron microscopy in stools of victims from one episode. one food handler was found to be excreting the virus, and there was evidence of a poor standard of hygiene in the kitchen. a food hi ...	1984	6086727
the childhood health effects of an improved water supply system on a remote panamanian island.	the incidence of diarrhea, respiratory disease, and skin infections was prospectively determined after the introduction of a system which distributed unlimited quantities of high quality fresh water to each of the 150 housing units on tupile, an island devoid of fresh water located off panama's caribbean coast and inhabited by 1,500 cuna indians. tupile residents used 7.1 liters of water/person/day compared to the 2.3 usage rate of inhabitants on achutupo, the control island. despite ready avail ...	1985	4037183
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
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
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
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
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
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
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
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
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
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
antigen detection in the diagnosis of norwalk virus gastroenteritis.		1986	3016117
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
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
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
leads from the mmwr. gastroenteritis on two caribbean cruise ships.		1986	3014174
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
gastroenteritis outbreaks on two caribbean cruise ships.		1986	3012310
an eight-year study of the viral agents of acute gastroenteritis in humans: ultrastructural observations and seasonal distribution with a major emphasis on coronavirus-like particles.	during an 8-yr period, 862 stool specimens from patients with gastroenteritis were examined by electron microscopy after negative staining with 2% phosphotungstic acid (ph 6.5). forty-one percent of the specimens submitted over an 8-yr period were determined to be positive for virus or viruslike particles belonging to one or more of seven morphologically distinct viral groups. coronavirus-like particles (cvlps) were present in 69.8% of the positive stool specimens. membranous profiles containing ...	1986	3011353
characterization of the snow mountain agent of viral gastroenteritis.	snow mountain agent (sma) is a 27- to 32-nm virus which is the etiologic agent of outbreaks of acute gastroenteritis in colorado and vermont. sma is morphologically similar to but antigenically distinct from the norwalk and hawaii agents of viral gastroenteritis but, like those agents, has not been cultivated in vitro. we purified and characterized sma directly from human stool specimens containing the virus. the density of the sma virion was 1.29 g/cm3 and 1.21 to 1.22 g/cm3 on potassium tartra ...	1986	3009862
radioimmunoassay for detection of the snow mountain agent of viral gastroenteritis.	the snow mountain agent (sma) is a norwalk-like viral agent of acute gastroenteritis that has been detected only by immune electron microscopy (iem). we established a solid phase microtiter radioimmunoassay (ria) for sma antigen employing pre-and post-challenge sera from volunteer studies as capture antibodies. sma was detected in 12 of 67 stool samples from volunteers who were ill after oral challenge with sma. all samples in which virus particles were detected by iem were positive by ria, but ...	1986	3009701
viral diarrhoea.	it is apparent from this review that great progress has been made over the past 10 years in defining the aetiology of viral diarrhoea. rotavirus is a major cause of gastroenteritis in children, particularly during the winter months. however, if bacteriological and virological data are pooled, our current aetiological knowledge reveals that a pathogen is not detected in 20 to 30% of cases in most perennial investigations. now that human rotavirus has been cultured, complete characterization may b ...	1986	3006951
norwalk like viruses: study of an outbreak.	an outbreak of acute non-bacterial gastroenteritis is reported, during which a ward had to be closed, and stool samples from 15 patients showed a virus structurally similar to the norwalk agent.	1986	3006605
widespread outbreaks of clam- and oyster-associated gastroenteritis. role of norwalk virus.	consumption of raw shellfish has long been known to be associated with individual cases and sporadic outbreaks of enteric illness. however, during 1982, outbreaks of gastroenteritis associated with eating raw shellfish reached epidemic proportions in new york state. between may 1 and december 31, there were 103 well-documented outbreaks in which 1017 persons became ill: 813 cases were related to eating clams, and 204 to eating oysters. the most common symptoms were diarrhea, nausea, abdominal cr ...	1986	3005857
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
other viruses with etiologic roles in childhood gastroenteritis.	rotaviruses and norwalk-like viruses are the two groups of viruses most frequently associated with gastroenteritis, but as outlined in this review several other viral agents have also been associated with acute gastroenteritis. the gastroenteritis viruses are generally fastidious, and thus traditional cell culture isolation and detection procedures are not applicable; therefore electron microscopy and immunoelectron microscopy remain among the most powerful techniques for studying these viruses. ...	1986	3003721
[epidemiology, etiology and laboratory diagnosis of infectious diarrhea diseases in the tropics].	diarrhoeal diseases belong to the leading causes of morbidity and mortality in tropical countries, especially in infants and small children. about one billion episodes are estimated for this group of age with 4.6 million fatalities. many causes are discussed to explain the high incidence: bottle feeding of infants, protein malnutrition, unsafe drinking water and unsafe disposal of excrements and sewage, unsufficient consciousness of personal and domestic hygiene, lack of knowledge on the origin ...	1985	3000920
detection of norwalk virus in stools by enzyme immunoassay.	the development of a solid-phase microtiter enzyme immunoassay (eia) for detection of norwalk virus antigen in stool samples is described. the eia was compared with a previously developed radioimmunoassay (ria) for detection of norwalk virus antigen in stools obtained from 30 volunteers who received norwalk virus. the eia detected viral antigen in stools from 17 of the volunteers and the ria detected viral antigen in 15. seroconversion was a more sensitive indicator of infection in some patients ...	1985	2997382
inactivation of norwalk virus in drinking water by chlorine.	norwalk virus in water was found to be more resistant to chlorine inactivation than poliovirus type 1 (lsc2ab), human rotavirus (wa), simian rotavirus (sa11), or f2 bacteriophage. a 3.75 mg/liter dose of chlorine was found to be effective against other viruses but failed to inactivate norwalk virus. the norwalk virus inoculum remained infectious for five of eight volunteers, despite the initial presence of free residual chlorine. infectivity in volunteers was demonstrated by seroconversion to no ...	1985	2996421
detection of norwalk virus antibodies and antigen with a biotin-avidin immunoassay.	biotin-avidin immunoassays (bais) were developed to detect norwalk virus antigen and to measure norwalk virus antibody. the bai detected norwalk virus infections by a fourfold titer rise in antibody in sera or by antigen in stool, with a sensitivity similar to or greater than that of the radioimmunoassay (ria), and the bai appeared to be more sensitive than the ria for detecting antibody in single serum specimens. the bai antigen test detected norwalk antigen in all stools that were positive by ...	1985	2993353
an outbreak of norwalk-related gastroenteritis at a boys' camp.	an acute gastrointestinal tract illness affected 213 (52%) of 407 campers and 64 (53%) of 121 staff members attending a boys' camp in the catoctin mountains of maryland during the summer of 1981. nausea was the predominant symptom for ill campers and staff members (73%), but more staff members experienced diarrhea (49%) than did campers (9%). twenty-three individuals had more than one episode of illness compatible with the case definition. eight of nine paired blood specimens from ill staff memb ...	1985	2992267
norwalk virus gastroenteritis. an outbreak associated with a cafeteria at a college.	an explosive outbreak of gastrointestinal illness occurred among students and employees at a small college in florida in november 1980. common symptoms were diarrhea, nausea, weakness, abdominal cramps, chills, vomiting, and low-grade fever. cases of illness were identified in 40% of 628 students and 15% of 162 employees who responded to a survey. among students, there was a sevenfold excess risk associated with eating one or more meals at the campus cafeteria november 3-5 (p much less than 0.00 ...	1985	2990197
transmission of viral infections by the water route: implications for developing countries.	the "enteric" virus group comprises greater than 100 different viruses. these viruses typically infect the cell lining of the alimentary canal and are discharged in very large numbers in the feces of infected persons. contamination of water supplies by enteric viruses represents an important source of viral infection. many communities, particularly in developing countries, depend on sewage-polluted sources for their recreational and drinking water. because conventional methods of sewage and wate ...	1985	2988098
[etiopathogenesis of infectious diarrheas].		1985	2986658
[viral diarrheas].	in the developing countries diarrhoea ranks among the most frequent diseases: 5-18 million children are estimated to die annually from gastro-intestinal infections. but also in europe and the usa diarrhoea is of utmost medical importance, especially among children and infants. it was only twelve years ago that 2 viral groups, the norwalk and the rotavirus group, were discovered to be etiological agents responsible for a large proportion of gastro-intestinal infections. whilst viruses of the norw ...	1985	2986379
travelers' diarrhea. nih consensus development conference.	diarrhea is the major health problem in travelers to developing countries. travel to high-risk areas in latin america, africa, the middle east, and asia is associated with diarrhea rates of 20% to 50%. the syndrome is caused by an infection acquired by ingesting fecally contaminated food or beverages. escherichia coli, a common species of enteric bacteria, is the leading pathogen, although a host of other bacteria, viruses, and protozoa have been implicated in some cases. prudent dietary and hyg ...	1985	2985834
prolonged outbreak of norwalk gastroenteritis in an isolated guest house.	during november and december 1982, a persistent outbreak of gastroenteritis took place in an isolated guest house. an estimated 26% of the changing population of guests and staff developed symptoms. laboratory studies implicated norwalk agent as the cause of illness, although the original source of the outbreak could not be established. information on clinical features of the illness, its mode of spread, and eventual control is presented.	1985	2984524
a statewide assessment of the role of norwalk virus in outbreaks of food-borne gastroenteritis.		1985	2982970
serologic survey of rotavirus, norwalk agent and prototheca wickerhamii in wastewater workers.	analysis of paired sera from 48 wastewater workers and controls who reported gastrointestinal illness did not reveal any excess of seroconversions to norwalk agent or to rotavirus. inexperienced wastewater-exposed workers had higher levels of antibody to norwalk agent than did experienced and control workers and those with high and medium aerosol exposure had higher titres than those in the low aerosol category. analysis for prototheca antibody titres was essentially negative.	1985	2981485
evidence of immunity induced by naturally acquired rotavirus and norwalk virus infection on two remote panamanian islands.	for better understanding of the role of humoral immunity in ameliorating infections with rotavirus (rv) and norwalk virus (nw), 305 cuna indians living on two isolated islands located off panama's carribean coast were surveyed daily for diarrhea over a seven-month period. nine (8%) of 108 persons with a baseline rv antibody titer of greater than 1:4 developed rv infection compared with 70 (46%) of 151 persons with a baseline rv antibody titer of less than 1:4 (p less than .001). thirty-eight (25 ...	1985	2981278
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
small round structured viruses and persistence of infectivity in food handlers.		1987	2889072
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
polymicrobial aetiology of travellers' diarrhoea.	of 35 us peace corps volunteers in thailand, 20 (57%) had a total of 30 episodes of diarrhoea during their first 6 weeks in the country. enteric pathogens were associated with 90% of the episodes. a single pathogen was identified in 17 (57%) episodes, 2-4 pathogens were identified in 10 (33%) episodes, and there were 15 symptomless infections. enterotoxigenic escherichia coli (etec) was identified in 37% of these episodes, and various salmonella serotypes were isolated in 33%. infections with 9 ...	1985	2857430
outbreak of gastroenteritis in a home for the aged--ontario.		1988	2854008
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 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
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
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
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
update of viral gastroenteritis.		1988	2834120
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
viral gastroenteritis--south dakota and new mexico.		1988	2828906
leads from the mmwr. viral gastroenteritis--south dakota and new mexico.		1988	2828698
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
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
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
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
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
small round structured viruses and their spread.		1989	2563823
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
viral enteritis in the 1980s: perspective, diagnosis and outlook for prevention.		1989	2549497