| norwalk virus in vomitus. | | 1979 | 83510 |
| immune response and prevalence of antibody to norwalk enteritis virus as determined by radioimmunoassay. | a solid-phase microtiter radioimmunoassay was established for the detection of norwalk virus and its antibody, with clinical materials from human volunteers previously studied in massachusetts as reagents. a study of 308 massachusetts residents showed that serum antibody to norwalk agent was rarely present during childhood but was detectable in approximately 50% of adults. all volunteers inoculated with norwalk virus who developed illness seroconverted (10/10), whereas only one-third (5/15) of n ... | 1979 | 118178 |
| implications of recent virological researches. | rotaviruses (duoviruses) can be found in more than half the cases of acute diarrhoea in children up to the age of six or seven. about that age almost everyone has antibodies to them. second infections occur and may not be as rare as laboratory findings so far suggest. very young infants sometimes get subclinical disease-the effect of maternal antibody transmitted across the placenta? very similar viruses, all possessing a common antigen detectable by immunofluorescence, are known to infect and/o ... | 1976 | 186237 |
| antibodies to viral gastroenteritis viruses in crohn's disease. | antibody prevalence and titer to rotavirus and norwalk virus were studied in crohn's disease patients and in age-, sex-, and time-matched controls. there were no significant antibody differences between the groups studied. | 1979 | 215490 |
| role of norwalk virus in outbreaks of nonbacterial gastroenteritis. | twenty-five separate outbreaks of nonbacterial gastrointestinal illnesses were studied serologically for evidence of infection with the norwalk virus and the rotaviruses that affect humans. eight of 25 outbreaks appeared to be related to the norwalk virus. in one of the 25 outbreaks, there was evidence of rotavirus infection. these observations suggest that the norwalk virus or serologically related agents play an important role in epidemic nonbacterial gastroenteritis in adults and older childr ... | 1979 | 220341 |
| prevalence of antibody to the norwalk virus in various countries. | serum samples from children and adults from several countries were tested by radioimmunoassay for antibody to the norwalk virus. antibody was commonly found in adults from all the countries tested. antibody appears to be acquired more rapidly in children from underdeveloped countries than in children from the united states. | 1979 | 227798 |
| an australia-wide outbreak of gastroenteritis from oysters caused by norwalk virus. | at least 2000 persons were involved in an australia-wide outbreak of oyster-associated food poisoning in june and july, 1978. at the time, this episode presented a major health risk to the community as a whole and has subsequently posed a serious economic problem for the oyster farming and distributing industry. although bacteriological investigations indicated some batches of oysters were contaminated by sewage, no bacterial cause could be established. the causative organism was shown to be nor ... | 1979 | 514174 |
| pattern of shedding of the norwalk particle in stools during experimentally induced gastroenteritis in volunteers as determined by immune electron microscopy. | in 11 of 23 volunteers the norwalk virus-like particle was visualized by immune electron microscopy in at least one stool specimen obtained during the acute phase of experimentally induced nonbacterial gastroenteritis. examination of multiple stool specimens obtained during the course of illness in these 11 volunteers revealed maximal concentration of norwalk virus-like particle at the onset of illness and shortly thereafter; in no case was the norwalk particle visualized in stools obtained befo ... | 1975 | 1151121 |
| 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 |
| 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 |
| the diagnosis of srsv infection. | | 1992 | 1284950 |
| pilot study of an extended range of potential etiologic agents of diarrhea in the israel defense forces. | | 1992 | 1310297 |
| 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 |
| [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 |
| 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 |
| 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 |
| [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 |
| 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 |
| viral gastroenteritis. | | 1991 | 1647494 |
| 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 |
| 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 |
| 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 |
| norwalk agent and other small-round structured viruses in the u.k. | | 1991 | 1661318 |
| [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 |
| [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 |
| [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-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 |
| 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 |
| gastroenteritis associated with shellfish. | | 1991 | 1669888 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| [gastroenteritis caused by norwalk-group viruses]. | | 1990 | 2158706 |
| norwalk agent comes of age. | | 1990 | 2160504 |
| foodborne gastroenteritis due to norwalk virus in a winnipeg hotel. | | 1990 | 2161705 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| two institutional outbreaks of norwalk-like gastroenteritis--ontario. | | 1989 | 2544302 |
| 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 |
| 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 |
| 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 |
| small round structured viruses and their spread. | | 1989 | 2563823 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| outbreak of gastroenteritis in a home for the aged--ontario. | | 1988 | 2854008 |
| foodborne gastroenteritis due to norwalk virus in a winnipeg hotel. | | 1990 | 2154305 |
| 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 |
| 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 |
| 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 |
| 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 |
| small round structured viruses and persistence of infectivity in food handlers. | | 1987 | 2889072 |
| 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 |
| 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 |
| 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 |
| a statewide assessment of the role of norwalk virus in outbreaks of food-borne gastroenteritis. | | 1985 | 2982970 |
| 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 |
| 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 |
| [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 |
| [etiopathogenesis of infectious diarrheas]. | | 1985 | 2986658 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 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 |
| [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 |
| 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 |
| 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 |