| [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 |
| waterborne disease outbreaks, 1986-1988. | from 1986 to 1988, 24 states and puerto rico reported 50 outbreaks of illness due to water that people intended to drink, affecting 25,846 persons. the protozoal parasite giardia lamblia was the agent most commonly implicated in outbreaks, as it has been for the last 10 years; many of these outbreaks were associated with ingestion of chlorinated but unfiltered surface water. shigella sonnei was the most commonly implicated bacterial pathogen; in outbreaks caused by this pathogen, water supplies ... | 1990 | 2156147 |
| 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 |
| 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 |
| clinical associations of norwalk-like virus in the stools of children. | from among 1,360 stool specimens examined during the 19-month period from march 1982 to september 1983, small round-structured viruses, morphologically indistinguishable from the norwalk agent, were detected by electron microscopy in 42 specimens from 28 children. diarrhoea was mild, and vomiting, although frequently observed, was not an invariable feature. mild pyrexia occurred in three patients. many cases occurred some time after admission to the ward; this and other features suggested a hosp ... | 1986 | 3016227 |
| norwalk-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 |
| 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 |
| 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 |
| micro-organisms in gastroenteritis. | we present bacteriological and virological findings together with salient clinical features from a prospective study of 447 children aged under 2 years admitted to hospital with infectious gastroenteritis. putative pathogenic micro-organisms were identified in the stools of 75% of these children. eight identifiably distinct groups of viruses, found on electron microscopy and tissue culture were present in 67% of patients--rotavirus was detected most frequently. pathogenic bacteria (salmonellas, ... | 1984 | 6091568 |
| an outbreak of food-borne gastroenteritis in two hospitals associated with a norwalk-like virus. | two connected outbreaks of gastroenteritis in separate hospitals associated with a small round structured virus morphologically indistinguishable from the norwalk virus are described. the virus was most probably introduced on chicken sandwiches prepared by a member of the kitchen staff who was incubating the disease. | 1983 | 6315816 |
| a multistate outbreak of oyster-associated gastroenteritis: implications for interstate tracing of contaminated shellfish. | in november 1993, clusters of gastroenteritis in six states following oyster consumption were investigated to identify common features, and stool samples were obtained to identify a pathogen. efforts were made to account for all potentially contaminated oysters using harvest tags and the interstate recall system. consumption of oysters was associated with illness in 10 clusters; no other food was implicated. a norwalk-like virus was detected by electron microscopy in 9 of 18 samples and by rever ... | 1995 | 7769284 |
| identification of minireovirus as a norwalk-like virus in pediatric patients with gastroenteritis. | in 1977, 30- to 32-nm virus-like particles, named minireovirus because of their unique morphologic appearance, were detected by electron microscopy in the stools of infants and young children with gastroenteritis. sequence analysis of approximately 2,800 consecutive bases derived from overlapping pcr clones of a recent minireovirus clinical isolate showed 52% nucleotide sequence identity with the norwalk virus sequence and, in addition, demonstrated that the genomic organizations of these two vi ... | 1994 | 8151799 |
| detection of norwalk virus or norwalk-like virus infections in finnish infants and young children. | norwalk virus (nv) and norwalk-like viruses are important causes of epidemic nonbacterial gastroenteritis in older children and adults. serologic responses to nv of 154 finnish infants and young children participating in a rotavirus vaccine study were examined by elisa with a recently available baculovirus-expressed recombinant nv capsid protein. in 4 serially collected sera (at the median ages of 3, 4, 14, and 23 months), 49% of children had at least one nv infection over the approximately 2-ye ... | 1994 | 8195618 |
| epidemiology of diarrheal disease outbreaks on cruise ships, 1986 through 1993. | to describe the epidemiology of cruise-associated diarrheal disease outbreaks from 1986 through 1993, to determine if the incidence had changed since 1985, and to determine the preventability of outbreaks that continue to occur. | 1996 | 8606476 |
| outbreaks of norwalk-like virus-associated gastroenteritis traced to shellfish: coexistence of two genotypes in one specimen. | we determined the nucleotide sequences of norwalk-like viruses in 10 pcr products from stool or oyster specimens obtained from four outbreaks of gastroenteritis in which shellfish was suspected as the cause in shizuoka prefecture in japan between 1987-94. the sequences were determined from nucleotide positions 4561-4852 (292 bp) in the polymerase region. two types of sequences were detected. one (genotype 1) had 87% sequence homology with the prototype norwalk virus, and the other (genotype 2) h ... | 1996 | 8666079 |
| an outbreak of norwalk-like virus infection in tokyo and saitama in late 1995. | | 1996 | 8890552 |
| [diagnosis and clinical manifestations of diarrheal virus infections in maizuru area from 1991 to 1994--especially focused on small round structured viruses]. | rotavirus (44.7%), adenovirus (5.6%), small round structured viruses such as astrovirus (9.8%) and norwalk like virus (6.9%) were detected by latex agglutination and reverse transcription polymerase chain reaction amplification from 378 stool samples in an outpatient clinic of pediatrics in maizuru area from 1991 to 1994. 70.0% were found from 6 months to 2 years old and 91.0% were detected from january to april. serotype 1 astrovirus and group 2 norwalk like virus were mainly found in all serot ... | 1996 | 8952271 |
| [outbreak of non-bacterial gastroenteritis in a school]. | an outbreak of gastroenteritis occurred in a school affecting more than 30% of its 535 students. an epidemiological survey questionnaire was given to all students as well as staff and maintenance personnel. stool cultures and electronic microscopy were used to detect the presence of a norwalk-like virus. several analyses of water samples were also done. this outbreak occurred simultaneously in the two wings of the school (east and south). those who used the east wing were most affected by the di ... | 1996 | 8964025 |
| [outbreak of food-borne gastroenteritis caused by a norwalk-like virus. evaluation of methods for confirmation of the etiology in suspected viral gastroenteritis]. | acute gastroenteritis is a common disease and can be food-borne. we describe an outbreak of acute gastroenteritis, probably caused by norwalk-like virus, which struck 250 people in the course of one week in a small norwegian community. the source of the infection was probably an infected food handler in a bakery who contaminated cream cakes with the virus. the sensitivity of electronmicroscopy and analyses of igg antibodies in serum to detect the etiologic agent was very low. the sensitivity to ... | 1996 | 9011988 |
| hospital outbreak of norwalk-like virus. | an outbreak of gastroenteritis caused by norwalk-like virus occurred in two areas of the hospital: area 1, consisting of three adjacent and interconnected wards, with mostly elderly patients; and area 22, an acute ward in a separate building with elderly patients. in area 1, 40 patients and 20 staff were affected; in area 2, 18 patients and 14 staff were affected. infection control measures were instituted in consultation with the government health authority. these measures did not appear to aff ... | 1997 | 9324510 |
| clinical features of infections due to escherichia coli producing heat-stable toxin during an outbreak in wisconsin: a rarely suspected cause of diarrhea in the united states. | in september 1994, a foodborne outbreak of enterotoxigenic escherichia coli (etec) infection occurred in attendees of a banquet in milwaukee. e. coli was isolated from stool specimens from 13 patients that were comprehensively tested; isolates from five patients were positive for e. coli producing heat-stable toxin, were biochemically identified and serotyped as e. coli o153:h45, and were all resistant to tetracycline, ampicillin, sulfisoxazole, and streptomycin. diarrhea (100%) and abdominal cr ... | 1998 | 9564472 |
| detection of norwalk-like virus genes in the caecum contents of pigs. | norwalk-like virus genes were detected by rt-pcr in the caecum contents of pigs. positive pcr products were produced from four out of 1,117 samples by nested pcr using human srsv primers. nucleotide sequences between 4,561 and 4,852 numbered according to the norwalk virus genomic rna in the rna polymerase region were determined. between the norwalk virus sequence and the sequences detected in pigs, there was 58.2% to 59.9% sequence homology. the swine sequences were located on genogroup ii of hu ... | 1998 | 9687878 |
| molecular detection of norwalk-like caliciviruses in sewage. | in this study, norwalk-like virus (nlv) rna was detected by reverse transcriptase pcr (rt-pcr) in sewage water concentrates. sequence analysis of the rt-pcr products revealed identical sequences in stools of patients and related sewage samples. in 6 of 11 outbreak-unrelated follow-up samples, multiple nlv genotypes were present. levels as high as 10(7) rna-containing particles per liter were found. these data show that high loads of nlvs may be present in sewage and warrant further studies addre ... | 1999 | 10584031 |
| investigation of an outbreak of gastroenteritis caused by norwalk-like virus, using solid phase immune electron microscopy. | in february 1993, 95 persons (47 patients and 48 staff members) were affected by an hospital outbreak of viral gastroenteritis. using direct electron microscopy (em) the causative agent was identified as a small round structured virus. this was confirmed as a norwalk-like virus using solid phase immune electron microscopy (spiem). of 94 stool samples examined, 12 (13%) samples containing small round structured viruses (srsv) were spiem positive for norwalk-like virus. a further 25 (27%) samples ... | 2000 | 10662561 |
| norwalk-like virus and bacterial pathogens associated with cases of gastroenteritis onboard a us navy ship. | acute gastroenteritis is a potential cause of substantial morbidity in u.s. military personnel during deployment. this study investigated the microbial causes of diarrhea in u.s. troops on exercises in southeast asia aboard the u.s.s. germantown from march through may 1996. a total of 49 (7%) patients with diarrhea reported to sick call during a 3-month deployment involving 721 personnel. diarrheal samples from 49 patients were subjected to bacterial and parasitologic examination, but sufficient ... | 1999 | 10674668 |
| expression of recombinant norwalk-like virus capsid proteins using a bacterial system and the development of its immunologic detection. | the capsid protein of norwalk-like virus (nlv) isolates nlv-36 (mexico virus type, genogroup ii [gii]), nlv-21 (lordsdale virus type, gii), nlv-114 (untyped gii virus), and nlv-96-908 (ky89 virus type, gi) have been expressed in an escherichia coli system. the expressed recombinant nlv capsid proteins, fused with maltose binding protein (mbp-rv) and thioredoxin (trx-rv) in e. coli lysate, were analyzed using sodium dodecyl sulfate-polyacrylamide gel eletrophoresis. rabbit igg (r-igg) in hyperimm ... | 2000 | 10686033 |
| evaluation of f-specific rna bacteriophage as a candidate human enteric virus indicator for bivalve molluscan shellfish. | escherichia coli is a widely utilized indicator of the sanitary quality of bivalve molluscan shellfish sold for human consumption. however, it is now well documented that shellfish that meet the e. coli standards for human consumption may contain human enteric viruses that cause gastroenteritis and hepatitis. in this study we investigated using f-specific rna bacteriophage (frna bacteriophage) to indicate the likely presence of such viruses in shellfish sold for consumption. frna bacteriophage a ... | 2000 | 10742200 |
| norwalk-like viral gastroenteritis outbreak in u.s. army trainees. | an outbreak of acute gastroenteritis hospitalized 99 (12%) of 835 u. s. army trainees at fort bliss, el paso, texas, from august 27 to september 1, 1998. reverse transcriptase polymerase chain reaction tests for norwalk-like virus were positive for genogroup 2. gastroenteritis was associated with one post dining facility and with soft drinks. | 2000 | 10756159 |
| confirmation of norwalk-like virus amplicons after rt-pcr by microplate hybridization and direct sequencing. | a large number of norwalk-like viruses (nlvs) have been identified from stool samples by rt-pcr by amplifying part of the polymerase-coding gene. a set of probes were selected based on sequence analysis of the viruses circulating in finland during the years 1996-97 for confirmation of the findings by hybridization. a microplate hybridization test, which provides a rapid semi-automatic detection for pcr products, was designed and compared with agarose gel electrophoresis. from the material of 210 ... | 1999 | 10598090 |
| open reading frame 1 of the norwalk-like virus camberwell: completion of sequence and expression in mammalian cells. | the orf1 sequence was determined for camberwell virus, a genogroup 2 norwalk-like virus, completing the full genome of 7,555 nucleotides. orf1 cdna was cloned into a simian virus 40-based expression vector, and the viral proteins synthesized following transfection into cos cells were analyzed. by using antisera directed against the helicase, protease, or polymerase regions, eight polypeptides ranging in size from 19 to 117 kda were detected by radioimmunoprecipitation. the cleavage sites determi ... | 1999 | 10559373 |
| combined infection of norwalk-like virus and verotoxin-producing bacteria associated with a gastroenteritis outbreak. | detection of multiple pathogens, particularly a combination of viruses and bacteria, is infrequently documented in outbreaks of gastroenteritis. this paper reports the presence of norwalk-like virus (nlv) and enterohaemorrhagic verotoxin-producing escherichia coli in one individual, and nlv and verotoxin-producing aeromonas sobria in another individual, both part of a large gastroenteritis outbreak. the causes of gastroenteritis in such outbreaks may be more complex than previously thought. | 1999 | 10892495 |
| outbreak of viral gastroenteritis due to drinking water contaminated by norwalk-like viruses. | heinävesi, a finnish municipality with a population of 4860 inhabitants, had an outbreak of gastroenteritis in march 1998. on the basis of an epidemiologic survey, an estimated 1700-3000 cases of acute gastroenteritis occurred during the outbreak. municipal water consumption was found to be associated with illness (risk ratio [rr]=3.5, 95% confidence interval, 3.11>rr>3.96). norwalk-like virus (nlv) genogroup ii (ggii) was identified in untreated water, treated water, and 4 tap water samples by ... | 1999 | 10558930 |
| three-year study to assess human enteric viruses in shellfish. | the main pathogenic enteric viruses able to persist in the environment, such as hepatitis a virus (hav), norwalk-like virus (nlv), enterovirus (ev), rotavirus (rv), and astrovirus (av), were detected by reverse transcription-pcr and hybridization in shellfish during a 3-year study. oyster samples (n = 108), occasionally containing bacteria, were less frequently contaminated, showing positivity for av (17%), nlv (23%), ev (19%), and rv (27%), whereas mussel samples, collected in areas routinely i ... | 2000 | 10919776 |
| [norwalk virus-like food poisoning after eating oysters]. | the aim of this study was to conduct a clinical-epidemiological and microbiological investigation into an outbreak of food-borne disease due to the consumption of oysters. | 2000 | 10923321 |
| a method to detect low levels of enteric viruses in contaminated oysters. | direct isolation and identification of pathogenic viruses from oysters implicated in gastroenteritis outbreaks are hampered by inefficient methods for recovering viruses, naturally occurring pcr inhibitors, and low levels of virus contamination. in this study we focused on developing rapid and efficient oyster-processing procedures that can be used for sensitive pcr detection of viruses in raw oysters. poliovirus type 3 (pv3) sabin strain was used to evaluate the efficacy of virus recovery and t ... | 1999 | 10543775 |
| immunoglobulin m antibody test to detect genogroup ii norwalk-like virus infection. | sera obtained from adult volunteers inoculated with genogroup ii norwalk-like viruses (nlvs), hawaii virus, and snow mountain virus and from patients involved in outbreaks of gastroenteritis were tested for genogroup ii nlv mexico virus-specific immunoglobulin m (igm) by use of a monoclonal antibody, recombinant mexico virus antigen (rmxv)-based igm capture enzyme-linked immunosorbent assay (elisa). sera from genogroup i norwalk virus (nv)-inoculated volunteers and from patients involved in a ge ... | 1999 | 10449486 |
| detection of sporadic cases of norwalk-like virus (nlv) and astrovirus infection in a single irish hospital from 1996 to 1998. | 'norwalk-like viruses' (nlv) and astroviruses are recognised as the most important etiologic agents of viral gastroenteritis, excluding rotaviruses. however, neither of these two groups of viruses is routinely screened for in irish hospital laboratories. | 2000 | 10942091 |
| foodborne viral illness--status in australia. | norwalk-like virus contamination of oysters and orange juice, and hepatitis a virus contamination of oysters have been responsible for large outbreaks of foodborne viral disease in australia. rotavirus, adenovirus, astrovirus, parvovirus and other enteroviruses also contribute to the incidence of gastroenteritis in this country but the role of foods and waters in transmitting these viruses is unclear. protocols for the investigation, surveillance and reporting of foodborne viral illness require ... | 2000 | 10946844 |
| norwalk-like viral gastroenteritis in u.s. army trainees--texas, 1998. | during august 27-september 1, 1998, 99 (12%) of 835 soldiers in one unit at a u.s. army training center in el paso, texas, were hospitalized for acute gastroenteritis (age). their symptoms included acute onset of vomiting, abdominal pain, diarrhea, and fever. review of medical center admission records for age during the previous year indicated that fewer than five cases occurred each month. this report describes the outbreak investigation initiated on august 30 by a u.s. army epidemiologic consu ... | 1999 | 10220254 |
| expression and self-assembly of grimsby virus: antigenic distinction from norwalk and mexico viruses. | a cdna obtained from grimsby virus (grv), a norwalk-like virus, purified from a stool sample of a symptomatic adult associated with a gastroenteritis outbreak in the united kingdom, was used to obtain the complete nucleotide sequence of the second open reading frame (orf2). the orf2 sequence of grv predicts a capsid of 539 amino acids (aa) which exhibits aa identities of 96% to lordsdale virus, 67% to mexico virus (mxv), and 43% to norwalk virus (nv). the grv capsid protein was expressed in inse ... | 1999 | 9874680 |
| [magnitude of rainfall on viral contamination of the marine environment during gastroenteritis epidemics in human coastal population]. | sewage treatments are not efficient to eliminate enteric microorganisms. viruses are able to persist and are discharged into the marine environment with treated effluents. few data are now available on the magnitude and the contributive processes of marine viral contamination. this work evaluates the relationship between the magnitude of rainfall and the viral contamination of the marine environment during winter epidemics of gastroenteritis in human coastal populations. | 2000 | 10992111 |
| serotype-specific antigen elisa for detection of chiba virus in stools. | chiba virus (cv), a norwalk-like virus (nlv), was first identified as a cause of oyster-associated outbreak of gastroenteritis that occurred in chiba prefecture, japan, in 1987. an enzyme-linked immunosorbent assay (elisa), based on hyperimmune antisera to recombinant baculovirus-expressed capsid proteins of cv (rcv), was developed to detect cv antigen in stools. no cross-reactions were observed with other enteric viruses including enteroviruses, rotaviruses, astroviruses, or enteric adenoviruse ... | 2000 | 11002253 |
| norwalk-like virus associated with gastroenteritis in babies. | | 1997 | 9076274 |
| steaming oysters does not prevent norwalk-like gastroenteritis. | to determine whether steaming oysters prevents gastroenteritis caused by small round structured (norwalk-like) viruses and to identify risk factors for illness. | 1996 | 8955700 |
| [outbreak of non-bacterial gastroenteritis in a school]. | an outbreak of gastroenteritis occurred in a school affecting more than 30% of its 535 students. an epidemiological survey questionnaire was given to all students as well as staff and maintenance personnel. stool cultures and electronic microscopy were used to detect the presence of a norwalk-like virus. several analyses of water samples were also done. this outbreak occurred simultaneously in the two wings of the school (east and south). those who used the east wing were most affected by the di ... | 1996 | 8771928 |
| outbreaks of gastroenteritis due to norwalk-like virus in two long-term care facilities for the elderly. | in february 1993, outbreaks of gastroenteritis due to norwalk-like viruses occurred simultaneously among the elderly residents of two long-term care facilities. facility a instituted infection control measures that included increased surveillance, reinforcement of handwashing, keeping symptomatic residents in their rooms and relieving symptomatic staff of their work duties until 48 h after resolution of their symptoms. facility b instituted a more stringent set of control measures that included ... | 1995 | 8547682 |
| an improved method for the detection of norwalk-like caliciviruses in environmental samples. | an original magnetic beads rna capture was developed for the detection of norwalk-like virus by rt-pcr. the same oligonucleotide was used both for capture and reverse transcription of the viral rna. the optimization studies showed that the most important parameter for sensitivity is the biotin-binding capacity of the beads. this method was found to be efficient for eliminating inhibitors in sewage samples compared with the classic rt-pcr. moreover, the sensitivity was greatly enhanced, allowing ... | 2000 | 11123547 |
| immunomagnetic separation of a norwalk-like virus (genogroup i) in artificially contaminated environmental water samples. | rabbit polyclonal antibodies were raised against a recombinant capsid protein from a genogroup i norwalk-like virus (nlv). magnetic beads coated with these antibodies were used in immunomagnetic separation (ims) of the nlv. after capture of the nlv and washing of the beads, viral rna was heat released and detected by rt-pcr. this ims procedure was shown to have high sensitivity for detection of homologous nlv, while capture of a genogroup ii nlv was less efficient. antigen capture was not influe ... | 2000 | 11139018 |
| sequence and genome organization of a human small round-structured (norwalk-like) virus. | small round-structured viruses (srsvs), also known as norwalk or norwalk-like viruses, are the major worldwide cause of acute, epidemic nonbacterial gastroenteritis in humans. these viruses, which contain a single-stranded rna genome, have remained refractory to molecular characterization because of the small amounts of virus in clinical samples and the absence of an animal model and an in vitro culture system. the complete genomic nucleotide sequence of an srsv, southampton virus, was determine ... | 1993 | 8380940 |
| multiple outbreaks of norwalk-like virus gastro-enteritis associated with a mediterranean-style restaurant. | the role of diverse infectious agents, particularly norwalk-like viruses (nlv), in three successive gastro-enteritis outbreaks in one setting (a restaurant) was evaluated. methods included standard bacteriological tests, specific tests for escherichia coli, tests for verocytotoxins, electron microscopy (em) for viruses and reverse transcription-pcr (rt-pcr) methodology for nlv. no pathogenic bacteria were detected. verocytotoxin genes, although detected by pcr in the first outbreak, could not be ... | 2001 | 11211221 |
| [outbreak of gastroenteritis at a home for the aged in albacete]. | we describe the investigation of an acute gastroenteritis outbreak with an explosive beginning, probably waterborne, that occurred in an nursing home in albacete, in november 1999 and affected 104 inmates and 35 employees. the dominant symptoms were diarrhea and vomiting. | 2000 | 11217245 |
| molecular characterization and expression of the capsid protein of a norwalk-like virus recovered from a desert shield troop with gastroenteritis. | norwalk virus (nv) infection was recently found to be associated with gastroenteritis in u.s. military troops stationed in saudi arabia during the 1990 desert shield operation. we identified a norwalk-like virus in the stools of two military personnel with gastroenteritis by elisa and iem. by rt-pcr and sequence analysis, the nucleotide sequence of part of the polymerase region of each of these two "desert shield" strains (dsv275 and dsv395) was found to be 73% identical to the corresponding reg ... | 1994 | 8128635 |
| effect of rotavirus vaccine on sapporo virus gastroenteritis in finnish infants. | sapporo-like viruses (slvs) occur worldwide, but there is limited information about the slv-associated gastroenteritis outside japan. | 2001 | 11303833 |
| transmission of a small round structured virus by vomiting during a hospital outbreak of gastroenteritis. | an outbreak of gastroenteritis due to a small round structured virus (srsv) (norwalk-like virus) occurred in an elderly care unit, affecting a total of 126 patients and staff. the outbreak caused major disruption to the provision of health care services by the unit over a 3-week period. following the outbreak a study was undertaken to explore risk factors for acquisition of srsv infection by health care workers on the unit. exposure to patients nearby who were vomiting and the number of close co ... | 1994 | 7915285 |
| molecular detection of human calicivirus in young children hospitalized with acute gastroenteritis in melbourne, australia, during 1999. | reverse transcription-pcr and sequence analysis identified calciviruses in 32 of 60 stool specimens (negative for other enteric pathogens) obtained from children admitted to our hospital with acute gastroenteritis. the overall annual incidence rate for calcivirus was 9% (32 of 354 children). molecular analysis identified 30 "norwalk-like virus" genogroup ii (predominantly lordsdale cluster) and 2 "sapporo-like virus" strains. | 2001 | 11427606 |
| university outbreak of calicivirus infection mistakenly attributed to shiga toxin-producing escherichia coli o157:h7--virginia, 2000. | on february 21-22, 2000, the virginia department of health (vdh) was notified by a university student health center of two suspected cases of escherichia coli o157:h7. at a local hospital laboratory, stool specimens from the two ill students tested positive for shiga toxin-producing e. coli (stec) using a commercially available enzyme immunoassay (eia) kit. further investigation revealed that the outbreak of gastrointestinal illness was caused by a norwalk-like virus (nlv), a member of the calic ... | 2001 | 11428728 |
| etiology of gastroenteritis in sentinel general practices in the netherlands. | data from a general practice-based, case-control study on gastroenteritis and the pathogens related to this disease were used to study the association between specific pathogens and the infected patients' ages and symptoms. for comparison, the occurrence of these pathogens in control patients, stratified by age, also is presented. in children with gastroenteritis who were <5 years of age, rotavirus (in 21% of patients) and norwalk-like virus (nlv; in 15%) were the most common pathogens. among pa ... | 2001 | 11438890 |
| gastroenteritis viruses: an overview. | acute gastroenteritis is among the most common illnesses of humankind, and its associated morbidity and mortality are greatest among those at the extremes of age, children and the elderly. in developing countries, gastroenteritis is a common cause of death in children < 5 years that can be linked to a wide variety of pathogens. in developed countries, while deaths from diarrhoea are less common, much illness leads to hospitalization or doctor visits. much of the gastroenteritis in children is ca ... | 2001 | 11444035 |
| [gastroenteritis outbreak associated with water consumption, possibly caused by norwalk or norwalk-like virus]. | it is described an acute gastroenteritis outbreak of probable hydric transmission in ontinyent (valencia). it was declared on the 31st of january, 1992 and affected 3541 people according to the declaration done by the sanitary services who attended the patients. the clinical situation was characterized by the presence of profuse and watery diarrhoea, nausea, vomiting, abdominal pain and fever or febricula. | 1995 | 7497350 |
| the frequency of a norwalk-like pattern of illness in outbreaks of acute gastroenteritis. | records of 642 outbreaks of acute gastroenteritis were reviewed to determine the proportion of outbreaks that were clinically and epidemiologically consistent with norwalk-like virus infection. using as our criteria stool cultures negative for bacterial pathogens, mean (or median) duration of illness 12-60 hours, vomiting in greater than or equal to 50 per cent of cases, and, if known, mean (or median) incubation period of 24-48 hours, we found that 23 per cent of waterborne outbreaks, 4 per cen ... | 1982 | 6291414 |
| direct exposure to animal enteric pathogens. | humans have very close interactions with working, food-producing, and companion animals. according to the american veterinary medical association, there are more than one hundred million cat and dog pets in the united states. furthermore, non-traditional pets like reptiles and exotic birds are not unusual companion animals in households. in addition to sharing with animals our living and/or working space and time, we also share, unfortunately, many disease causing microorganisms. in the past few ... | 2001 | 11512628 |
| from the centers for disease control and prevention. norwalk-like virus outbreaks at two summer camps--wisconsin, june 2001. | | 2001 | 11575312 |
| 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 |
| multistate outbreak of norwalk-like virus gastroenteritis associated with a common caterer. | in february 2000, an outbreak of gastroenteritis occurred among employees of a car dealership in new york. the same meal was also supplied to 52 dealerships nationwide, and 13 states reported illness at dealerships where the banquet was served. a retrospective cohort study was conducted to identify risk factors associated with the illness. stool samples were collected to detect norwalk-like virus, and sera were drawn and tested for immunoglobulin a antibodies to the outbreak strain. by univariat ... | 2001 | 11724717 |
| 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 |
| 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 |
| 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 |
| 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 |
| norwalk-like virus infection in military forces: epidemic potential, sporadic disease, and the future direction of prevention and control efforts. | the impact of norwalk-like virus (nlv) infection on military forces is evaluated in this report. nlvs were a major cause of both outbreaks and sporadic disease among crowded us ground troops in the 1991 war with iraq. nlvs also have been found to be a cause of acute gastroenteritis in other ground and shipboard deployments. four large outbreaks of acute gastroenteritis were investigated aboard us navy aircraft carriers between 1992 and 1997. in these outbreaks, nlvs were identified as the probab ... | 2000 | 10804153 |
| epidemiologic profiling: evaluating foodborne outbreaks for which no pathogen was isolated by routine laboratory testing: united states, 1982-9. | the objective was to evaluate foodborne outbreaks of undetermined aetiology by comparing them to pathogen-specific epidemiologic profiles of laboratory-confirmed foodborne outbreaks. national foodborne outbreak data reported to cdc during 1982-9 were categorized by clinico-epidemiologic profiles based on incubation, duration, percent vomiting, fever and vomiting to fever ratio. from the pathogen-specific profiles, five syndromes were developed: a vomiting-toxin syndrome resembling bacillus cereu ... | 2001 | 11811869 |
| detection of norwalk-like virus in shellfish implicated in illness. | in the 1990s, norwalk-like viruses (nlvs) were identified in patient specimens as the primary pathogen associated with shellfish-borne gastroenteritis in the united states. identification of these viruses from implicated shellfish has been difficult due to inefficient recovery of viruses, natural polymerase chain reaction (pcr) inhibitors in shellfish, and low virus contamination. recent improvements to the method of detecting nlvs in shellfish include enhanced processing of virus and shellfish ... | 2000 | 10804149 |
| genetic classification of "norwalk-like viruses.. | reverse transcription-polymerase chain reaction has been used worldwide for the diagnosis of norwalk-like virus (nlv) infection, yet a commonly accepted genetic classification scheme has not been established. amino acid sequences from four regions of open-reading frame 2 (orf2) were used to analyze 101 nlv strains, including 2 bovine strains. on the basis of this analysis, a genetic classification scheme is proposed that differentiates 99 human strains into 2 major genetic groups consisting of 5 ... | 2000 | 10804147 |
| seroprevalence and seroincidence of norwalk-like virus infection among brazilian infants and children. | to determine the importance of norwalk-like viruses (nlvs) as pediatric pathogens in a developing country, the seroprevalence and seroincidence of this group of viruses in a cohort of children less than 4 years of age in an urban shantytown in northeastern brazil was examined. serum samples were collected approximately every 6 months from 135 children who were surveyed three times each week for diarrhea and vomiting. nlv igg was measured by an enzyme immunosorbent assay (eia) with recombinant no ... | 2000 | 10745243 |
| the heteroduplex mobility assay (hma) as a pre-sequencing screen for norwalk-like viruses. | molecular epidemiological studies of norwalk-like viruses (nlvs), previously known as small round structured viruses (srsvs), are dependant currently on dna sequencing of pcr amplicons, which is expensive and time consuming. the heteroduplex mobility assay (hma) was evaluated as a method for identification of pcr amplicons from the commonly circulating nlv strains without dna sequencing. the procedure was developed for use with two reference strains, a mexico virus-like strain (mxv-like; hu¿nlv¿ ... | 2000 | 10856763 |
| antigenic diversity of norwalk-like viruses: expression of the capsid protein of a genogroup i virus, distantly related to norwalk virus. | the gene encoding the capsid protein of a genogroup i norwalk-like virus (nlv) (hu/nlv/stav/95/nor) was cloned and expressed in insect cells using a baculovirus vector. the his-tagged recombinant capsid protein (rstav) was antigenic and immunogenic, showed an apparent molecular weight of approximately 68 kd in protein gels, and was only soluble under denaturing conditions. the amino acid sequence of the rstav protein showed 65-88% similarity to capsid protein sequences from other genogroup i nlv ... | 2000 | 10893150 |
| identification of active-site amino acid residues in the chiba virus 3c-like protease. | the 3c-like protease of the chiba virus, a norwalk-like virus, is one of the chymotrypsin-like proteases. to identify active-site amino acid residues in this protease, 37 charged amino acid residues and a putative nucleophile, cys139, within the gdcg sequence were individually replaced with ala in the 3bc precursor, followed by expression in escherichia coli, where the active 3c-like protease would cleave 3bc into 3b (vpg) and 3c (protease). among 38 ala mutants, 7 mutants (r8a, h30a, k88a, r89a ... | 2002 | 12021327 |
| waterborne outbreak of norwalk-like virus gastroenteritis at a tourist resort, italy. | in july 2000, an outbreak of gastroenteritis occurred at a tourist resort in the gulf of taranto in southern italy. illness in 344 people, 69 of whom were staff members, met the case definition. norwalk-like virus (nlv) was found in 22 of 28 stool specimens tested. the source of illness was likely contaminated drinking water, as environmental inspection identified a breakdown in the resort water system and tap water samples were contaminated with fecal bacteria. attack rates were increased (51.4 ... | 2002 | 12023910 |
| distinct epidemiological patterns of norwalk-like virus infection. | norwalk-like viruses (nlv) are important economically as a cause of both sporadic gastroenteritis in the community and large outbreaks in hospitals and other institutional settings. despite the description of several antigenic types relatively little is known about the epidemiology of these individual types. nlvs were detected by electron microscopy in faecal specimens from 706 outbreaks of gastroenteritis that represented 68% of all outbreaks of non-bacterial gastroenteritis. these outbreaks to ... | 2000 | 10935995 |
| norwalk-like virus as a cause of a gastroenteritis outbreak in a childcare centre. | | 2000 | 10937421 |
| genetic diversity and molecular epidemiology of norwalk-like viruses. | specimens (n=287) from 59 gastroenteritis outbreaks collected from february 1997 to march 1999 were analyzed by reverse transcriptase-polymerase chain reaction. the majority of outbreaks (88%) were associated with norwalk-like viruses. molecular analyses of strains from 46 outbreaks showed the cocirculation during the 1998-1999 winter of 2 genogroup ii clusters, accounting for 57% and 28% of outbreaks, respectively. an important genetic diversity was observed during this 2-year period. thirteen ... | 2000 | 10950761 |
| foodborne outbreak caused by a norwalk-like virus in india. | an outbreak of acute gastroenteritis occurred in the nurses' hostel of a civil hospital in delhi, after a farewell party involving 130 nurses and some of the housekeeping staff. all affected persons had eaten salad sandwiches at the party. stool samples were collected from six of these patients on the second day of infection. all six samples, when tested for the presence of common bacteria, parasites, and rotavirus, were found to be negative. the clinical features of this outbreak matched the cr ... | 2002 | 12116011 |
| evidence for airborne transmission of norwalk-like virus (nlv) in a hotel restaurant. | an outbreak of gastroenteritis followed a meal in a large hotel during which one of the diners vomited. the clinical features of the illness suggested norwalk-like virus (nlv, small round structured virus) infection, and this was confirmed by electron microscopy and reverse transcriptase polymerase chain reaction (rt-pcr) of stool samples. further characterization of the virus by nucleotide sequence analysis of the pcr amplicons revealed identical strains in all the affected individuals. the foo ... | 2000 | 10982072 |
| three nursing home outbreaks of norwalk-like virus in brisbane in 1999. | we report on three nursing home outbreaks of gastroenteritis in brisbane in 1999. the presence of norwalk-like virus (nlv) genogroup 2 was demonstrated by reverse transcription polymerase chain reaction (rt-pcr) in all three outbreaks. common findings of these investigations were rapid spread of the illness within the institutions and difficulties in identifying a common source. nursing home populations are vulnerable and it is important for each institution to have infection control policies in ... | 2000 | 11022388 |
| widespread environmental contamination with norwalk-like viruses (nlv) detected in a prolonged hotel outbreak of gastroenteritis. | a protracted outbreak of norwalk-like virus (nlv)-associated gastroenteritis occurred in a large hotel in north-west england between january and may 1996. we investigated the pattern of environmental contamination with nlv in the hotel during and after the outbreak. in the ninth week, 144 environmental swabs taken from around the hotel were tested for nlv by nested rt-pcr. the sites were categorized according to the likelihood of direct contamination with vomit/faeces. the highest proportion of ... | 2000 | 11057964 |
| transmission of norwalk virus during football game. | during a college football game in florida, diarrhea and vomiting developed in many of the members of a north carolina team. the next day, similar symptoms developed in some of the players on the opposing team. | 2000 | 11071673 |
| norwalk-like virus sequences detected by reverse transcription-polymerase chain reaction in mineral waters imported into or bottled in switzerland. | norwalk-like viruses (nlvs) is a genus belonging to the caliciviridae. nlvs are transmitted by the fecal-oral and the aerosol route and are the most common cause of outbreaks of nonbacterial gastroenteritis. nlvs are responsible for an estimated 67% of all illnesses caused by known foodborne pathogens and for 96% of nonbacterial gastroenteritis in the united states. many outbreaks could be associated with the consumption of primarily or secondarily contaminated foods. to our knowledge, no epidem ... | 2000 | 11079703 |
| a large hotel outbreak of norwalk-like virus gastroenteritis among three groups of guests and hotel employees in virginia. | a large outbreak of acute gastroenteritis occurred among three different groups of guests and the employees of a virginia hotel within a 2-week period in november 2000. at least 76 of the hotel's guests and 40 hotel employees had acute gastroenteritis during this period. all tested ill persons were infected with the same strain of norwalk-like virus, as shown by cloning and sequencing of virus detected in stool specimens from the three guest groups and the employees. epidemiologic investigation ... | 2002 | 12211579 |
| polypeptide p41 of a norwalk-like virus is a nucleic acid-independent nucleoside triphosphatase. | southampton virus (shv) is a member of the norwalk-like viruses (nlvs), one of four genera of the family caliciviridae. the genome of shv contains three open reading frames (orfs). orf 1 encodes a polyprotein that is autocatalytically processed into six proteins, one of which is p41. p41 shares sequence motifs with protein 2c of picornaviruses and superfamily 3 helicases. we have expressed p41 of shv in bacteria. purified p41 exhibited nucleoside triphosphate (ntp)-binding and ntp hydrolysis act ... | 2001 | 11160659 |
| high level excretion of norwalk-like virus following resolution of clinical illness. | we report the case of an elderly woman excreting high levels (about 5 x 10(5) virions per gram of faeces) of norwalk-like virus (nlv) in the absence of any clinical symptoms of gastroenteritis. analysis by reverse transcription, polymerase chain reaction and dna sequencing was carried out on a 342-nucleotide region of open reading frame 1. this indicated that the nlv belonged to genogroup 2 and was more closely related to the camberwell subgroup, the most common circulating in southeast australi ... | 2001 | 11280609 |
| norwalk like virus by light cycler pcr. | | 2002 | 12367659 |
| rational optimization of generic primers used for norwalk-like virus detection by reverse transcriptase polymerase chain reaction. | | 2002 | 12367660 |
| from the centers for disease control and prevention. norwalk-like virus-associated gastroenteritis in a large, high-density encampment--virginia, july 201. | | 2002 | 12375589 |
| enteropathogens associated with acute diarrhea in community and hospital patients in jakarta, indonesia. | the prevalence of bacteria, parasite and viral pathogens in 3875 patients with diarrhea in community and hospital settings from march 1997 through august 1999 in jakarta, indonesia was determined using routine bacteriology and molecular assay techniques. bacterial pathogens isolated from hospital patients were, in decreasing frequency, vibrio cholerae o1, shigella flexneri, salmonella spp. and campylobacter jejuni, while s. flexneri, v. cholerae o1, salmonella spp. and c. jejuni were isolated fr ... | 2002 | 12381465 |
| heminested multiplex reverse transcription-pcr for detection and differentiation of norwalk-like virus genogroups 1 and 2 in fecal samples. | the present study describes a heminested multiplex reverse transcription (rt)-pcr assay which enables simultaneous detection and differentiation of norwalk-like virus (nlv) genogroups from clinical fecal samples without the need to perform sequencing or hybridization. the assay developed was able to detect concentrations of fewer than 100 viral particles per 5 microl of clarified fecal extract and could differentiate the two genogroups with a specificity of 100%. although the multiplex rt-pcr as ... | 2001 | 11427598 |
| clinical spectrum and transmission characteristics of infection with norwalk-like virus: findings from a large community outbreak in sweden. | a large foodborne outbreak caused by norwalk-like virus (nlv) among children and staff at 30 day care centers provided an opportunity to study symptomatology and attack rates among patients in different age groups, as well as secondary transmission rates in centers and households. a retrospective cohort study of 775 subjects from 13 randomly chosen centers was performed. diarrhea was more common in adults than in children (p=.001), whereas the reverse was noted with regard to vomiting (p=.003). ... | 2001 | 11477530 |
| sensitive detection of rna viruses associated with gastroenteritis by a hanging-drop single-tube nested reverse transcription-pcr method. | the detection of the human rna viruses, calicivirus and astrovirus, requires high sensitivity and broad reactivity. a novel single-tube nested reverse transcription-pcr (rt-pcr) method is described here, in which all of the required reagents are included in the one tube; however, those required for the nested amplification are separated in a "hanging drop" in the cap to be introduced by centrifugation after the rt and first-round cdna amplification steps. broad reactivity was obtained by using p ... | 2002 | 12409380 |
| rapid response and strict control measures can contain a hospital outbreak of norwalk-like virus. | norwalk-like viruses (nlvs) are a major cause of sporadic gastroenteritis in the community and of large outbreaks of gastroenteritis in hospitals and other institutions. in january 2001, 38 staff and 20 patients on an acute elderly care ward became ill in an outbreak of gastrointestinal infection. using reverse transcription polymerase chain reaction (rt-pcr) the causative agent was identified as nlv. no link was found between particular foods eaten and illness. at various times in the course of ... | 2002 | 12434696 |
| distribution of human virus contamination in shellfish from different growing areas in greece, spain, sweden, and the united kingdom. | viral pollution in shellfish has been analyzed simultaneously across a wide range of geographical regions, with emphasis on the concomitant variations in physicochemical characteristics and social features. the methods for sample treatment and for the detection of human enteric viruses were optimized by the participating laboratories. the second part of this study involves the selection of a protocol for virus detection, which was validated by analyzing the distribution and concentration of huma ... | 2002 | 12450820 |
| raw oyster consumption and outbreaks of viral gastroenteritis in new zealand: evidence for risk to the public's health. | to investigate the relationship between consumption of raw pacific half shell oysters and outbreaks of norwalk-like virus (nlv) gastroenteritis in auckland in the last third of 1999. | 2001 | 11494991 |
| modified concentration method for the detection of enteric viruses on fruits and vegetables by reverse transcriptase-polymerase chain reaction or cell culture. | fruits and vegetables may act as a vehicle of human enteric virus if they are irrigated with sewage-contaminated water or prepared by infected food handlers. an elution-concentration method was modified to efficiently detect, by reverse transcriptase-polymerase chain reaction (rt-pcr) or by cell culture, contamination by poliovirus, hepatitis a virus (hav), and norwalk-like virus (nlv) of various fresh and frozen berries and fresh vegetables. the protocol included washing the fruit or vegetable ... | 2002 | 12495017 |