| astrovirus-like particles associated with hepatitis in ducklings. | | 1984 | 6424324 |
| construction of a genome-length cdna clone for human astrovirus serotype 1 and synthesis of infectious rna transcripts. | we have constructed a genome-length cdna clone for human astrovirus serotype 1. when a human colon cancer-derived cell line, caco-2, is transfected with rna transcribed in vitro from this cdna clone, infectious virus is produced at titers close to those observed after infection with intact astrovirus. a rodent cell line, bhk, which is largely refractory to astrovirus infection, was found to support efficient growth of the virus if transfected with viral rna. the high transfection efficiency seen ... | 1997 | 8995706 |
| development of simple latex agglutination test for detection of astrovirus serotype 1. | astroviruses are small rna viruses associated with pediatric gastroenteritis. a latex agglutination (la) test is more convenient and rapid than electron microscopy, enzyme immunoassay (eia) and reverse transcription-polymerase chain reaction (rt-pcr) for detection of astroviruses in stool specimens was developed by using polyclonal antibody against cultured serotype 1 astrovirus, and tested on astrovirus positive- and negative- samples collected between 1985 and 1993 in ehime, japan. cultured se ... | 2000 | 11175443 |
| historical background and classification of caliciviruses and astroviruses. | infections caused by caliciviruses, i.e., vesicular exanthema virus of swine were recognised as a major cause of economic loss in the 1930s. however, it was not until the application of electronmicroscopy in the 1970s that caliciviruses and astroviruses were recognised and proven to be a cause of diarrhoea and vomiting. the following review briefly describes the steps which have led to the development of diagnostic tests and enabled the characterization of several members of the caliciviridae an ... | 1996 | 9015119 |
| gastroenteritis viruses: research update and perspectives. gastroenteritis viruses, novartis foundation symposium 238, london, uk, 16-18 may 2000. | | 2000 | 11184182 |
| [astrovirus constellation: emerging agents in acute gastroenteritis]. | | 2000 | 11188904 |
| [diarrhea caused by adenovirus and astrovirus in hospitalized immunodeficient patients]. | acute or chronic diarrheal illness are common complications in immunosuppressed patients such as human immunodeficiency virus (hiv)-infected, bone marrow or solid organ transplanted patients and those with leukaemias or other immune deficiency disorders. due to the importance of recognizing the feasible etiologies of diarrhea in order to give the proper antimicrobial chemotherapy or to avoid a misdiagnosis of rejection in the case of transplanted patients, we have investigated adenovirus and ast ... | 2001 | 11256256 |
| [astroviruses]. | | 2000 | 11276809 |
| comparison of capsid sequences from human and animal astroviruses. | we have sequenced the genomic 3'-end, including the structural gene, of human astrovirus (hastv) serotype 7 and morphologically related viruses infecting pig (pastv), sheep (oastv) and turkey (tastv-1). these sequences were compared with corresponding astrovirus sequences available in the nucleic acid databases, including sequences of the seven other hastv serotypes, two other avian astroviruses (tastv-2 and avian nephritis virus) and astrovirus from cat (fastv). a 35 nt stem-loop motif near the ... | 2001 | 11297680 |
| the molecular biology of astroviruses. | astroviruses (genus astrovirus) are assigned to a newly established virus family, the astroviridae. the molecular biology of these agents reveals many features unique amongst the non-enveloped animal viruses and resembles that of members of certain plant virus families. in particular, their possession of a serine protease and use of ribosomal frameshifting to express the rna polymerase are similar to the luteoviruses. many aspects of the astrovirus replication strategy are still unclear, but rep ... | 1996 | 9015125 |
| molecular characterisation of the 3'-end of the astrovirus genome. | we have sequenced the 3'-end of the rna genomes of 14 serotyped and 12 untyped isolates of human astrovirus. the sequences, which include all 8 serotypes, were used to predict secondary structures, postulate possible functional domains, reveal conserved regions suitable for nucleic acid amplification and perform phylogenetic analysis. the final nucleotides of the capsid protein precursor gene and the adjacent 3'-noncoding region were highly conserved and, except for 35 nucleotides with homology ... | 1997 | 9170498 |
| astrovirus survival in drinking water. | a method based on infection of caco-2 cultured cell monolayers (cc) and reverse transcription-pcr (rt-pcr) was developed for the specific detection of infectious astrovirus. the procedure was validated by titrating poliovirus stocks in parallel in caco-2 cells by determining the most probable number of cytopathogenic units and by cell culture and subsequent rt-pcr (cc-rt-pcr). cc-rt-pcr was then employed to measure the persistence of astrovirus suspended in dechlorinated tap water. after 60 days ... | 1997 | 9251198 |
| a prospective case-control study of the role of astrovirus in acute diarrhea among hospitalized young children. | this study examines the importance of astroviruses as a cause of acute diarrhea in hospitalized children <10 years old during a 5-year period. stools were screened by electron microscopy and were tested for astrovirus, rotavirus, and enteric adenovirus by eia. during the study, 14.6% of hospitalized children had diarrhea. astroviruses were second only to rotaviruses as etiologic agents of both community-acquired and nosocomial diarrhea. community-acquired astrovirus infection occurred in 6.8% of ... | 2001 | 11398103 |
| detection and genetic differentiation of human astroviruses: phylogenetic grouping varies by coding region. | astroviruses are single-stranded, positive-sense rna viruses that are associated with gastroenteritis in humans and animals. we describe a reverse transcription-polymerase chain reaction (rt-pcr) assay using primers targeted to a nonstructural protein coding region that allowed sensitive detection and genetic typing of representative strains of seven astrovirus serotypes. phylogenetic analysis of the nucleotide sequences of pcr products from the reference strains and several wild isolates indica ... | 1997 | 9267446 |
| genetic analysis of the capsid region of human astrovirus serotype 3 isolated in japan. | the total capsid region of astrovirus serotype 3 was analyzed using five isolates including four from japan and one from the united kingdom. the nucleic acid and deduced amino acid sequences in the region were homologous (over 97%). however, the sequences of serotype 3 were different from those of serotypes 1, 2, 4, 5, 6 and 8, especially in the c terminus. | 1997 | 9310946 |
| characterization of human serotype 1 astrovirus-neutralizing epitopes. | astroviruses are important agents of pediatric gastroenteritis. to better understand astrovirus antigenic structure and the basis of protective immunity, monoclonal antibodies (mabs) were produced against serotype 1 human astrovirus. four mabs were generated. one mab (8g4) was nonneutralizing but reacted to all seven serotypes of astrovirus by enzyme-linked immunosorbentassay (elisa) and immunoperoxidase staining of infected cells. three mabs were found to have potent neutralizing activity again ... | 1997 | 9343224 |
| cd4+ t cells with specific reactivity against astrovirus isolated from normal human small intestine. | the gut is the largest immunologic organ in the human body, but little is known about the antigen specificity of mucosal t cells. this study sought to determine whether t cells resident in the duodenal mucosa could recognize astrovirus, a common and clinically important gastroenteritis virus. serum antibodies against astrovirus are prevalent, indicating frequent viral exposure and postinfectious induction of systemic immune responses. mucosal immune responses may conceivably mediate protection o ... | 1998 | 9428225 |
| age-stratified seroprevalence of neutralizing antibodies to astrovirus types 1 to 7 in humans in the netherlands. | astroviruses are a new family of positive-stranded rna viruses that cause gastroenteritis in a wide range of animals and in humans. seven types of astrovirus, tentatively considered serotypes, have been distinguished by enzyme-linked immunosorbent assays (elisa) or immunoelectron microscopy, but it is unclear whether the serotype designation is used properly. to test human sera for the presence of neutralizing antibodies and to type field strains, neutralization tests (nt) using caco2 tissue-cul ... | 1998 | 9455876 |
| 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 |
| [astrovirus infection in children with gastroenteritis]. | we report here a 2 year study (1997-1998) of astrovirus infection in children admitted to our hospital. the epidmioligical and clinical features of the infection were also investigated. | 2001 | 11446906 |
| determination of serotypes of astroviruses by reverse transcription-polymerase chain reaction and homologies of the types by the sequencing of japanese isolates. | human standard astroviruses, serotypes 1 to 7, and 35 japanese isolates were typed by reverse transcription and polymerase chain reaction (rt-pcr) with serotype-specific primers for the first time. the results were identical with those obtained by enzyme immunoassay with serotype-specific polyclonal antibodies, a method which has already been reported. rt-pcr with serotype-specific primers is useful for epidemiological studies of astroviruses where serotype-specific polyclonal antibodies are not ... | 1998 | 9776395 |
| astrovirus detection in wastewater samples. | procedures for the detection of astroviruses in wastewater samples have been developed and evaluated. following these methodologies, we investigated the occurrence of astroviruses in wastewater samples from three different sewage treatments plants located in southern france and two in the barcelona area. some positive samples were genotyped by analysis of a fragment of the orf1a by restriction fragment length polymorphism (rflp) with endonuclease ddei. the amplimers generated contain several sit ... | 2001 | 11464772 |
| diagnosis of enteric pathogens in children with gastroenteritis. | the aim of this study was to determine the isolation trends of common and emerging pathogens in children over a 12-month period. the study group included 412 children under 6 years with diarrhoea who were either hospitalised, or seen in the outpatients department of the sydney children's hospital. pathogens were detected in 137 (33%) samples, with rotavirus most common (40%), followed by adenovirus (26%), astrovirus (12%), campylobacter jejuni (12%), salmonella spp. (10%) and giardia lamblia (< ... | 2001 | 11523939 |
| potential role of fomites in the vehicular transmission of human astroviruses. | the persistence of human astroviruses dried on representative porous (paper) and nonporous (china) surfaces was investigated. long-term astrovirus survival on fomites was monitored by an integrated cell culture-reverse transcription-pcr procedure. viruses were applied to inanimate surfaces in the presence and absence of fecal material, and their survival was assayed at 4 and 20 degrees c with high relative humidity. astroviruses exhibited a notable persistence when dried on porous and nonporous ... | 2001 | 11525984 |
| determination of a universal nucleic acid extraction procedure for pcr detection of gastroenteritis viruses in faecal specimens. | four nucleic acid extraction protocols were examined for their suitability for extraction of the ssrna, dsrna and dsdna genomes of gastroenteritis viruses, for pcr detection. protocol (a), employed specimen lysis with guanidinium thiocyanate, extraction with phenol-chloroform-isoamyl alcohol and nucleic acid purification by size-fractionated silica particles. protocol (b), utilised specimen lysis with guanidinium thiocyanate and nucleic acid purification by silica, followed by phenol-chloroform- ... | 2002 | 11742648 |
| expression and processing of nonstructural proteins of the human astroviruses. | the human astroviruses (hast) are increasingly recognized as an important cause of gastroenteritis. these viruses contain a 6.8-kb positive-sense, single-stranded rna molecule that is infectious when transfected into permissive cells. the hast gene 1 is composed of two open reading frames (orfs 1a and 1b) connected by a ribosomal frameshift. gene 1 is predicted to encode two nonstructural polyproteins (pp 1a and pp 1ab), and analysis of the hast gene 1 sequence has resulted in predictions of a s ... | 1998 | 9782307 |
| molecular epidemiology of astrovirus infection in barcelona, spain. | a 3-year study involving 2,347 gastroenteritis samples was conducted to determine the prevalence, time distribution, and medical significance of human astrovirus infection in barcelona, spain. the overall incidence of astrovirus was found to be 4.9%. mixed infections with other enteric agents were detected in 17.2% of all astrovirus-positive samples. during the 3-year period, the highest astrovirus incidence was reported in the winter months, although infections also occurred in summer. the peak ... | 2002 | 11773106 |
| an outbreak of gastroenteritis associated with astrovirus serotype 1 in a day care center, in rio de janeiro, brazil. | between june 4th and june 20th 1996 rotavirus, adenovirus, and astrovirus (hastrv) were investigated in fecal samples from 27 children under three years old with acute diarrhea, attending the bertha lutz day care center, in rio de janeiro. all fecal samples were analyzed by polyacrylamide gel electrophoresis (page), reverse transcriptase polymerase chain reaction (rt-pcr), enzyme immunoassays (eia), and electron microscopy (em). nine of them (33%) showed positive results for hastrv by at least o ... | 2001 | 11784924 |
| hla restriction patterns of gliadin- and astrovirus-specific cd4+ t cells isolated in parallel from the small intestine of celiac disease patients. | celiac disease is a common hla-dq2-associated enteropathy caused by an abnormal t-cell-mediated immune response to ingested wheat gliadin proteins. we have previously isolated in situ activated mucosal t cells from celiac disease patients and demonstrated that these t cells were gliadin specific and predominantly dq2 restricted. in contrast to this, gliadin-specific t cells isolated from peripheral blood display a variable hla restriction pattern, thereby indicating that the skewed dq restrictio ... | 1998 | 9864029 |
| genetic variation in the capsid region of human astrovirus serotype 4 isolated in japan. | the entire capsid regions of 12 serotype-4 astroviruses from japan were sequenced and compared with those of other serotypes. serotype-4 isolates were divided into two new subgroups. the intrasubgroup nucleic acid and deduced amino acid sequences were quite homologous (more than 93%), but slightly less so between subgroups (almost 85%). however, the serotype-4 sequences differed from those of serotypes 1, 2, 3, 5, 6, 7 and 8 (less than 50%). determining whether these differences significantly al ... | 1999 | 10609617 |
| proteolytic processing of the astrovirus capsid. | to further characterize the nature of proteolytic processing of the astrovirus capsid, we infected caco-2 cells with a high multiplicity of astrovirus without trypsin in the presence of 5 to 10% fetal calf serum. these infections were characterized by pulse-chase labeling with [35s]smethionine, electron microscopy, gel electrophoresis of purified viral particles, and analysis of infectivity of such particles with and without added trypsin. pulse-chase experiments showed that the astrovirus capsi ... | 2000 | 10644354 |
| astrovirus enteritis in a chronic lymphocytic leukemia patient treated with fludarabine monophosphate. | we report on a case of severe astrovirus gastroenteritis in a chronic lymphocytic leukemia (cll) patient treated with fludarabine monophosphate (famp). astrovirus was detected in stools using both an immunoenzymatic assay and an electronic microscopy analysis. treatment consisted in symptomatic care and the outcome was favorable. astrovirus infection might constitute a common etiology of gastroenteritis in patients with hematologic malignancies that have been severely immunocompromised with famp ... | 2000 | 10663621 |
| epidemiology of astrovirus infection in zaria, nigeria. | astrovirus has been shown to be an important aetiological agent associated with gastroenteritis in children, although few studies have been conducted in africa. in this study, stool specimens were obtained from 375 young children less than 5 years of age with acute gastroenteritis presenting at ahmadu bello university hospital, and from a control group of 122 children without diarrhoeal illness. the specimens were examined for the presence of human astroviruses using a monoclonal antibody-based ... | 2002 | 12022437 |
| studies on intracellular processing of the capsid protein of human astrovirus serotype 1 in infected cells. | astroviruses are non-enveloped, positive-strand rna viruses. their structural (capsid) protein is processed extracellularly into several smaller fragments which are found on the mature viral particle. in addition, intracellular cleavage of the capsid protein has been proposed. however, analysis of capsid protein processing has been hampered by the lack of antibodies to regions near the n and c termini of the protein. here we describe the construction of two infectious mutants of human astrovirus ... | 2002 | 12075088 |
| epidemiology of astrovirus infection in young children hospitalized with acute gastroenteritis in melbourne, australia, over a period of four consecutive years, 1995 to 1998. | the incidence of astrovirus infection in children less than 5 years of age hospitalized with acute gastroenteritis in melbourne, australia, from 1995 to 1998 was determined. astrovirus was detected in 40 of 449 specimens tested by northern hybridization, and astrovirus infection was confirmed by reverse transcription-pcr with or without culture in caco-2 cells. this represented 3.0% (40 of 1, 327) of all children tested for enteric pathogens, including viral, bacterial, and parasitic pathogens, ... | 2000 | 10698996 |
| molecular characterization of an avian astrovirus. | astroviruses are known to cause enteric disease in several animal species, including turkeys. however, only human astroviruses have been well characterized at the nucleotide level. herein we report the nucleotide sequence, genomic organization, and predicted amino acid sequence of a turkey astrovirus isolated from poults with an emerging enteric disease. | 2000 | 10846102 |
| astrovirus, adenovirus, and rotavirus in hospitalized children: prevalence and association with gastroenteritis. | agents of viral gastroenteritis such as astrovirus, rotavirus, and adenovirus are common pediatric pathogens accounting for many physician visits, hospital admissions, and nosocomial infections. previous hospital-based prevalence studies have examined mainly symptomatic children. | 2002 | 12142812 |
| identification of human astrovirus infections from stool samples with diarrhea in korea. | human astrovirus (hastv) infections were confirmed in 17 (1.5%) of 1153 children and adults with diarrhea, from different regions of korea, by testing their stool samples by reverse transcription-polymerase chain reaction using primers targeted to partial orf 1a. genotypes of isolates were determined by sequencing the 289-bp pcr products. the predominant genotype was hastv type 1, with intragenotypic variation of 0.7%. unlike norwalk-like viruses (nlvs), rotavirus and enteric adenovirus, no data ... | 2002 | 12209320 |
| detection and genotyping of astroviruses from children with acute gastroenteritis from goiânia, goiás, brazil. | the astroviruses constitute important agents of childhood diarrhea. the purpose of our research was to detect and genotype astroviruses in fecal samples from children with acute gastroenteritis from goiânia- goiás, brazil. | 2002 | 12218943 |
| localization of astrovirus in experimentally infected turkeys as determined by in situ hybridization. | twenty-one 3-day-old turkey poults from british united turkeys of america were orally inoculated with a recently characterized astrovirus, tastv-2, isolated from turkeys with poult enteritis and mortality syndrome. at 1, 2, 3, 4, 5, 7, and 9 days postinfection (dpi), three inoculated birds were euthanatized, and tissues (intestines, spleen, bursa, and thymus) were collected immediately into 10% neutral buffered formalin. inoculated birds were diarrheic by 3 dpi, and frothy feces persisted throug ... | 2002 | 12243474 |
| identification of viral agents causing gastroenteritis among children in buenos aires, argentina. | gastroenteritis is one of the most common diseases affecting children and rotavirus is the major etiological agent worldwide. although the role of rotaviruses as a causal agent of gastroenteritis has been previously established in argentina, little is known about the frequency of other gastrointestinal viruses. | 2002 | 12367655 |
| molecular epidemiology of astroviruses in japan from 1995 to 1998 by reverse transcription-polymerase chain reaction with serotype-specific primers (1 to 8). | in addition to the serotype-specific primers described previously (1 to 7), a new serotype 8-specific primer has been designed, allowing detection of all astrovirus serotypes. a total of 1,382 diarrheal stool samples in 5 regions in japan were examined by reverse transcription-polymerase chain reaction (rt-pcr). the incidence of astrovirus infection in all 5 regions was 5.9% (82 of 1,382 samples) and infection occurred mainly from november to april. serotypes 1, 3, and 4 were detected in 66, 14, ... | 2000 | 10861640 |
| 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 |
| incidence of human astrovirus in central australia (1995 to 1998) and comparison of deduced serotypes detected from 1981 to 1998. | the incidence of astrovirus infection was determined among infants and young children admitted to alice springs hospital (central australia) with gastroenteritis from 1995 to 1998. astrovirus was detected by reverse transcription-pcr in 33 of 495 stool samples, and this represented 4.3% of a total of 774 stool samples tested for astrovirus, rotavirus, and norwalk-like viruses. astrovirus incidence was substantially lower than that of rotavirus but higher than that of norwalk-like viruses both ov ... | 2002 | 12409383 |
| virus diversity in a winter epidemic of acute diarrhea in france. | in france, an epidemic peak of acute diarrhea is observed each winter. previous results suggested a viral etiology for these winter epidemics. we investigated the role of enteric viruses in acute diarrhea and their molecular diversity. one hundred sixty-one patients with acute diarrhea and 45 healthy patients (controls) from the general population were given a standardized questionnaire between december 1998 and may 1999. stool specimens were screened for group a and c rotaviruses, human caliciv ... | 2002 | 12409408 |
| astrovirus-associated diarrhea in south african adults. | | 2002 | 12439820 |
| astrovirus acute gastroenteritis among children in madrid, spain. | human astroviruses cause infantile gastroenteritis worldwide, but the prevalence of disease varies greatly by setting. since 1997 we have conducted a survey to determine the causes of diarrhea among spanish children attending an emergency room in madrid and to characterize the clinical features of viral-associated gastroenteritis. | 2002 | 12442026 |
| astrovirus gastroenteritis. | | 2002 | 12442031 |
| molecular characterization of astroviruses by reverse transcriptase pcr and sequence analysis: comparison of clinical and environmental isolates from south africa. | a comparative analysis was performed with 25 isolates of astroviruses (astvs) detected in sewage sources and 22 concurrently identified clinical astv isolates from the tshwane (pretoria) metropolitan area in south africa. the samples and specimens were screened for astvs by using an enzyme immunoassay and/or a reverse transcriptase pcr (rt-pcr) for the highly conserved untranslated region (3' end) of the genome. the rt-pcr results were confirmed by oligonucleotide probe dot blot hybridization. v ... | 2003 | 12570991 |
| complete genomic sequences of astroviruses from sheep and turkey: comparison with related viruses. | the genomes of astroviruses infecting sheep and turkey were sequenced. detailed analyses of these sequences were performed, including comparison with the other complete astrovirus sequences available as well as with other rna virus sequences, with focus on the non-structural proteins and rna sequences. earlier postulated functional astrovirus rna motifs and protein domains could in most cases be recognised in the sheep and turkey astrovirus sequences. in addition, analyses of the available astro ... | 2003 | 12573498 |
| characterization of rotaviruses causing diarrhoea in vietnamese children. | faecal samples from 123 children admitted to the centre for tropical diseases in ho chi minh city, vietnam, with acute watery diarrhoea were screened by negative-stain electron microscopy for viral enteropathogens. in addition to the 48 children who were found to be infected with rotavirus only, one had both rotavirus and astrovirus, two had adenovirus 40/41, and one had astrovirus only. the rotaviruses were subjected to molecular analysis by electropherotyping, g- and p-genotyping (by reverse-t ... | 2003 | 12662422 |
| viruses causing gastroenteritis. | acute gastroenteritis is one of the most common diseases in humans worldwide. viruses are recognized as important causes of this disease, particularly in children. since the norwalk virus was identified as a cause of gastroenteritis, the number of viral agents associated with diarrheal disease in humans has steadily increased. rotavirus is the most common cause of severe diarrhea in children under 5 years of age. astrovirus, calicivirus and enteric adenovirus are also important etiologic agents ... | 2003 | 12667234 |
| infantile viral gastroenteritis: on the way to closing the diagnostic gap. | a total of 305 faecal specimens collected from children under the age of 5 who presented with symptoms of acute gastroenteritis either as inpatients at addenbrooke's hospital (n = 100) or to general practitioners in east anglia (n = 205) during 1999-2001 were tested for the presence of rotavirus, norovirus, sapovirus, enteric adenoviruses (group f, serotypes 40 and 41), and astrovirus. an aetiologic agent was found in 184 specimens (60.3%). the most commonly found single viral pathogen was rotav ... | 2003 | 12696113 |
| [astrovirus and enteric adenovirus]. | | 2003 | 12722208 |
| are waterborne astrovirus implicated in acute digestive morbidity (e.mi.r.a. study)? | with rotavirus and norwalk-like viruses, astroviruses are now recognized as important etiologic agents of viral gastroenteritis in all age groups. however, astrovirus is neither routinely screened for in stool samples, nor in environmental samples, and data on the health impact of waterborne astrovirus are lacking. | 2003 | 12727532 |
| first rotavirus, now astrovirus: the evolving benefits of rt-pcr. | we compared rt-pcr and a newly developed amplified eia for the detection of human astrovirus (hastv) in 48 stool samples taken from children of less than five years of age with gastroenteritis. the rt-pcr classified more samples as positive than the eia (18 versus 8). without sensitive diagnosis, infection control policies will be disadvantaged and the true economic burden of hastv underestimated. | 2003 | 12736977 |
| development of a rapid method using nucleic acid sequence-based amplification for the detection of astrovirus. | we have developed a rapid method to detect astrovirus in fecal specimens utilizing nucleic acid sequence-based amplification (nasba) and several detection methodologies, including a sandwich hybridization assay based on dna-tagged liposomes (liposome-strip detection assay). rna was extracted from 65 stool specimens that were positive for astrovirus by enzyme immunoassay and was amplified by both nasba and reverse transcriptase pcr (rt-pcr). also extracted and amplified were 19 specimens containi ... | 2003 | 12798238 |
| astrovirus infection in children. | public health concerns related to enteric viral agents, such as astroviruses and caliciviruses, include their ability to cause sporadic diarrhea, large outbreaks of gastroenteritis, and hospitalizations or deaths resulting from vomiting, diarrhea, and dehydration. improved surveillance and application of sensitive molecular assays has increased awareness of these enteric pathogens and reduced the 'diagnostic gap' or unknown causes of non-bacterial gastroenteritis. | 2003 | 12821816 |
| astrovirus diarrhea in egyptian children. | this study describes the epidemiology of astrovirus diarrhea among a population-based cohort of 397 children aged <3 years residing in rural egypt from 1995 to 1998. the age-specific incidence rates of astrovirus diarrheal episodes per person-year were 0.38 for infants aged <6 months, 0.40 for those aged 6-11 months, 0.16 for those aged 12-23 months, and 0.05 for those aged 24-35 months. the overall incidence rate of astrovirus diarrhea was the same as that of rotavirus diarrhea, 0.19 episodes p ... | 2000 | 10950760 |
| persistent gastroenteritis in children infected with astrovirus: association with serotype-3 strains. | the relationship between cases of persistent diarrhoea and the levels and type of human astrovirus was investigated. the potential correlation between human astrovirus excretion levels and the occurrence of protracted gastroenteritis was elucidated after quantifying astroviruses in faecal samples by a competitive rt-pcr. this assay was developed employing an internal rna standard constructed for this purpose and showed a threshold of positivity of 3.4 x 10(4) genomes per gram of faeces. by this ... | 2003 | 12938199 |
| profile-profile comparisons by compass predict intricate homologies between protein families. | recently we proposed a novel method of alignment-alignment comparison, compass (the tool for comparison of multiple protein alignments with assessment of statistical significance). here we present several examples of the relations between pfam protein families that were detected by compass and that lead to the predictions of presently unresolved protein structures. we discuss relatively straightforward compass predictions that are new and interesting to us, and that would require a substantial t ... | 2003 | 14500884 |
| the development of sensitive latex agglutination tests for detecting astroviruses (serotypes 1 and 3) from clinical stool specimen. | astrovirus is a small single strand rna virus, that are associated with pediatric gastroenteritis. in order to detect astrovirus, latex agglutination test (la) is simpler, more convenient and rapid diagnostic method for detection of viruses in stool specimens than that of electron microscopy (em) or reverse transcriptase-polymerase chain reaction (rt-pcr). latex reagents was developed with cultured astroviruses serotypes 1 and 3, and tested on rotaviruses- and adenoviruses-negative stool specime ... | 2003 | 14509941 |
| identification and type distribution of astroviruses among children with gastroenteritis in colombia and venezuela. | astrovirus infections were detected by enzyme immunoassay in 12 (5%) of 251 stool samples from children with gastroenteritis from bogota, colombia. in addition, astroviruses were detected by reverse transcription-pcr in 3 (10%) of 29 stool samples negative for other enteric pathogens collected in caracas, venezuela, from children with gastroenteritis. astrovirus type 1 was the most frequently detected virus. | 2000 | 10970410 |
| molecular analysis of a serotype 8 human astrovirus genome. | human astroviruses are an important cause of gastroenteritis. as part of a molecular epidemiological study carried out in mexico a human astrovirus isolate, yuc-8, was adapted to grow in caco-2 cells, and its entire genome was sequenced. a 15 amino acid deletion in orf1a, which has been associated with adaptation of astroviruses to grow in cells other than caco-2, was present in yuc-8. comparative sequence analysis of the yuc-8 orf2 with reported human astrovirus sequences revealed that this iso ... | 2000 | 11086120 |
| characterization of "norwalk-like viruses" and astroviruses by liquid hybridization assay. | "norwalk-like viruses" (nlvs) and human astroviruses are causative agents of gastroenteritis in all age-groups. the typing of these agents is generally done by nucleotide sequencing, blot hybridization, or enzyme immunoassay. these techniques are expensive, time-consuming, and sometimes require scarce reagents, which limits the typing of nlvs and astroviruses to a few reference laboratories. this report describes a liquid hybridization assay that uses broadly reactive probes whose sequences are ... | 2001 | 11164493 |
| molecular epidemiology of human astrovirus diarrhea among children from a periurban community of mexico city. | human astroviruses (hastvs) were detected in 23 stool samples from 365 diarrhea episodes among 214 children (<18 months old) prospectively monitored for diarrhea in mexico city. stool samples were tested by eia and reverse transcriptase-polymerase chain reaction (rt-pcr) analysis. eia was less sensitive (74%) and equally specific, compared with rt-pcr analysis using type-common primers for hastv detection. of 31 hastv isolates, eia typed 18 (69%) of 26 eia-positive samples, and rt-pcr analysis t ... | 2001 | 11181143 |
| detection of norovirus (gi, gii), sapovirus and astrovirus in fecal samples using reverse transcription single-round multiplex pcr. | a reverse transcription (rt) single-round multiplex polymerase chain reaction (smpcr) assay was developed to detect simultaneously norovirus genogroup i and ii, sapovirus and astrovirus. a total of 377 diarrhea stool samples (screened for rotavirus- and adenorivus-negative) from four regions in japan during july 2000 to june 2001 were examined by rt-smpcr. the positive rate was 16.4% (62 out of 377 stool samples). norovirus, sapovirus and astrovirus were detected in 42, 16, 4 of 60 positive samp ... | 2003 | 14599677 |
| detection and sequence analysis of danish and swedish strains of mink astrovirus. | the sequences of mink astroviruses collected from 11 farms in denmark and sweden were analyzed and found to be homologous with one another but different from those of other astroviruses. a species-specific reverse transcriptase-pcr for mink astrovirus was established and shown to be suitable for the analysis of clinical samples. | 2003 | 14605160 |
| inactivation of an astrovirus associated with poult enteritis mortality syndrome. | outbreaks of poult enteritis mortality syndrome (pems) continue to cause financial losses to the turkey industry. clinically, pems is defined by mortality profiles, diarrhea, flock unevenness, and immunosuppression. pems is a very difficult disease to control and prevent. depopulation of pems-affected flocks and thorough cleaning of the contaminated housing have failed to prevent infection (disease) in subsequent flock placements. the relationship of pems to other enteric disease complexes of yo ... | 2001 | 11332502 |
| prevalence and characterization of astroviruses in argentinean children with acute gastroenteritis. | among viral agents causing gastroenteritis, human astroviruses (hastvs) take second or third place, after rotaviruses and caliciviruses, as the most frequent cause of illness. the aims of this study were to determine the prevalence of hastv infection and to characterize the circulating hastv strains in children with diarrhea under 3 years of age treated between 1995 and 1998 at out- or in-patient facilities of the children's hospital in mendoza, argentina. reverse transcription-polymerase chain ... | 2004 | 14635014 |
| molecular characterization of human astroviruses in germany. | the molecular epidemiology of human astroviruses (hastv) was studied using fecal specimens from different regions in germany during 1998/99 by rt-pcr and sequencing of orf2 amplicons. hastv of genotypes 1-4 were found to cocirculate in germany. the complete sequence of one isolate representing genogroup 3 (putative serotype 3) was determined. | 2001 | 11338382 |
| [detection of astrovirus rna from sewage works, seawater and native oysters samples in chiba city, japan using reverse transcription-polymerase chain reaction]. | through a year from april, 1999 to march, 2000, 20 samples, which consisted of raw sewage (2), chlorine-treated sewage (2), seawater (10) and naturally grown oysters (6), were collected monthly both from the sewage works at mihama-ku, chiba city and at a yacht harbor in chiba city bay, japan. astrovirus rna were detected by reverse transcription-polymerase chain reaction (rt-pcr) and was typed by direct sequencing. astrovirus positive products were detected from 9 samples (raw sewage; 1/2, chlor ... | 2001 | 11357315 |
| prevalence and genetic diversity of human astroviruses in mexican children with symptomatic and asymptomatic infections. | the prevalence and type diversity of human astroviruses (hastv) in children with symptomatic and asymptomatic infections were determined in five localities of mexico. hastv were detected in 4.6 (24 of 522) and 2.6% (11 of 428) of children with and without diarrhea, respectively. genotyping of the detected strains showed that at least seven (types 1 to 4 and 6 to 8) of the eight known hastv types circulated in mexico between october 1994 and march 1995. hastv types 1 and 3 were the most prevalent ... | 2004 | 14715746 |
| genetic analysis of the capsid region of astroviruses. | eight serotypes of human astroviruses (hastv-1 to hastv-8) have been described. to date, the entire genomes of hastv-1 and hastv-2 as well as the orf2 sequences of hastv-1-6 and 8 have been reported. in this study, the orf2 sequences of seventeen strains of hastvs originating from different countries were determined, as well as the sequence orf2 of one porcine astrovirus (pastv) strain. afterwards, comparison of the capsid protein precursors encoded by orf2 of 46 strains of hastvs, pastv, and fe ... | 2001 | 11424111 |
| characterisation of a south african human astrovirus as type 8 by antigenic and genetic analyses. | human astroviruses (hastv) can, on the basis of immunoassays using type-specific rabbit antisera, be classified into eight serotypes that correlate with genotypes. very few isolates of hastv type 8 have been described and there is a paucity of data available with regard to the antigenic and genetic relationships between hastv type 8 (hastv-8) and hastv types 1 (hastv-1) to 7 (hastv-7). a wild-type hastv from a south african paediatric patient with diarrhoea was analysed antigenically, by immune ... | 2001 | 11424112 |
| apoptosis in astrovirus-infected caco-2 cells. | cell death processes during human astrovirus replication in caco-2 cells and their underlying mechanisms were investigated. morphological and biochemical alterations typical of apoptosis were analyzed in infected cells using a combination of techniques, including dapi staining, the sub-g(0)/g(1) technique and the tunel assay. the onset of apoptosis was directly proportional to the virus multiplicity of infection. transient expression experiments showed a direct link between astrovirus orf1a enco ... | 2004 | 14980485 |
| astrovirus infection in young children with diarrhea hospitalized at beijing children's hospital. | this study was to assess certain epidemiological and clinical characteristics of astrovirus infection in children with diarrhea below 5 years old hospitalized at the beijing children's hospital. | 2004 | 15043772 |
| molecular epidemiology of viral gastroenteritis in asia. | acute gastroenteritis is one of the most common diseases in humans, and continues to be a significant cause of mortality and morbidity worldwide. recently the estimates of mortality associated with diarrhea declined, however the majority of deaths still occur in developing countries and thus urgent intervention is needed for the prevention of these diseases. in asian countries it is very important to study the distribution, transmission and characteristics of prevalent viruses in order to produc ... | 2004 | 15056259 |
| an outbreak of viral gastroenteritis in a mother-and-child health clinic. | an outbreak of diarrhoeal disease in a modern mother-and-child health clinic prompted the health authorities to initiate a retrospective cohort study in order to assess the scope of the outbreak and to identify possible risk factors. the management of the clinic had been rather concerned because four similar outbreaks had occurred during the last two years. a total of 151 guests, i.e. mothers with their children, who had arrived some days before the peak of the outbreak for a three-week-stay and ... | 2001 | 11434217 |
| [winter viruses]. | | 2004 | 15119334 |
| molecular epidemiology of childhood astrovirus infection in child care centers. | this study assessed the role of human astrovirus (hastv) in outbreaks and sporadic cases of diarrhea among children attending child care centers (cccs) and determined the infecting astrovirus antigenic types by reverse transcriptase-polymerase chain reaction (rt-pcr) and sequence analysis. eight astrovirus outbreaks occurred in 6 cccs. of 179 children with diarrhea, 36 (20%) had astrovirus-associated diarrhea. diarrhea stools obtained during diarrhea outbreaks were more likely to contain astrovi ... | 1999 | 10395872 |
| childhood astrovirus-associated diarrhea in the ambulatory setting in a public hospital in cordoba city, argentina. | human astroviruses have been increasingly identified as important agents of diarrheal disease in children. however, the disease burden of astrovirus infection is still incompletely assessed. this paper reports results on the epidemiological and clinical characteristics of astrovirus-associated diarrhea, as well as the impact of astrovirus infection on the ambulatory setting at a public hospital in córdoba city, argentina. from february 2001 through january 2002, 97 randomly selected outpatient v ... | 2004 | 15141279 |
| a simple and rapid single-step multiplex rt-pcr to detect norovirus, astrovirus and adenovirus in clinical stool samples. | a single-step multiplex reverse transcription-polymerase chain reaction (rt-pcr) assay that detects and identifies norovirus, astrovirus and adenovirus in clinical stool samples is described. four hundred sixty stool samples were tested from patients with non-rotavirus acute gastroenteritis, that were either stored at -80 degrees c and tested retrospectively, or tested immediately after viral nucleic acid extraction in a prospective manner, including outbreaks of gastroenteritis that occurred in ... | 2004 | 15158068 |
| diversity of enteric viruses detected in patients with gastroenteritis in a tertiary referral paediatric hospital. | the genetic diversity of enteric viruses co-circulating in a cohort of patients with viral gastroenteritis in a large tertiary paediatric hospital in london, uk, was determined. multiple strains of noroviruses (nv), sapoviruses (sv) and astroviruses (hasv) were detected in these patients, indicating the likelihood of multiple introductions from different sources, possible sub-clinical infections and simultaneous infection with different viruses in immunocompromised and other patients. routine sc ... | 2004 | 15170641 |
| processing and intracellular location of human astrovirus non-structural proteins. | human astrovirus (hast) non-structural polyproteins are encoded in two open reading frames linked in expression by a ribosomal frameshifting event. the first of these (orf 1a) specifies the serine protease, whilst the second (orf 1b) encodes the virus rna-dependent rna polymerase. the orf 1a product contains an unusual motif for small rna viruses which could potentially direct proteins to the cell nucleus. we have expressed part of orf 1a containing this motif and the whole of orf 1b separately ... | 1999 | 10573153 |
| the isolation and characterisation of astroviruses from chickens. | the isolation, cultivation and characterization of three chicken astroviruses (castv) isolates are described. they are antigenically related to each other but unrelated to avian nephritis virus (anv) and duck hepatitis virus type 2 (dvh2) in neutralization, immunofluorescence and gel diffusion tests. castv, anv and dvh2 all grew well in the lmh cell line, which was used for assay and serological tests. serological surveys in 1982 and 2001 showed that antibody to castv virus was widespread in bro ... | 2004 | 15223568 |
| one-year survey of astrovirus infection in children with gastroenteritis in a large hospital in hungary: occurrence and genetic analysis of astroviruses. | human astroviruses (hastv) are the causative agents of viral gastroenteritis mainly in children worldwide. this study investigated the epidemiology and genotype diversity of hastvs detected in children admitted to hospital with gastroenteritis in hungary. stool samples were collected from children with diarrhea at the municipal "szent lászló" hospital, budapest, hungary, between january 2002 and december 2002. of 2,758 samples, 607 were negative for both rotaviruses and bacterial pathogens and w ... | 2004 | 15258971 |
| virus diversity and an outbreak of group c rotavirus among infants and children with diarrhea in maizuru city, japan during 2002-2003. | a total of 236 fecal specimens collected from infants and children with gastroenteritis in maizuru city, japan from july 2002 to june 2003, were tested for the presence of rotaviruses, noroviruses, sapoviruses, astroviruses, and adenoviruses by rt-pcr, page, rpha, and latex agglutination methods. among diarrheal viruses detected, group a rotavirus was the most prevalent (32.2%; 76 of 236) followed by norovirus gii (21.2%; 50 of 236), group c rotavirus (10.2%; 24 of 236), adenovirus (3.8%; 9 of 2 ... | 2004 | 15258985 |
| caspases mediate processing of the capsid precursor and cell release of human astroviruses. | in this work we have shown that astrovirus infection induces apoptosis of caco-2 cells, since fragmentation of cellular dna, cleavage of cellular proteins which are substrate of activated caspases, and a change in the mitochondrial transmembrane potential occur upon virus infection. the human astrovirus yuc8 polyprotein capsid precursor vp90 is initially processed to yield vp70, and we have shown that this processing is trypsin independent and occurs intracellularly through four cleavages at its ... | 2004 | 15280469 |
| processing of nonstructural protein 1a of human astrovirus. | astrovirus contains three open reading frames (orf) on its genomic rna, orf1a, orf1b, and orf2. orf1a encodes a 920-amino-acid (aa) nonstructural protein, nsp1a, which displays a 3c-like serine protease motif. little is known about the processing of nsp1a or whether the protease it contains is active and involved in autocatalytic processing. here we address both of these matters. intact and n-terminally deleted forms of orf1a from human astrovirus serotype 1 were expressed in bhk cells, and nsp1 ... | 2002 | 11799197 |
| molecular characterization of a novel recombinant strain of human astrovirus associated with gastroenteritis in children. | we report a naturally occurring human astrovirus (hastv) strain detected in two different geographic locations. we identified two isolates of this strain in a diarrhea outbreak at a child care center in houston, texas; and two isolates in diarrhea stool samples from two children in mexico city. all four isolates were detected in stool samples by enzyme immunoassay (eia). one of the mexican isolates was typed by eia and all four isolates were hastv-5 by typing rt-pcr. the four isolates were >97% ... | 2001 | 11811685 |
| a review of viral gastroenteritis. | since kapakian first identified a virus in the stool of a patient with diarrhoea in 1972, many viruses have been described that cause diarrhoea directly or indirectly. it is now appreciated that viruses are the most common cause of diarrhoeal illness worldwide. although bacteria and other pathogens cause significant numbers of gastroenteritis, it is the viruses that are dealt with in this review. the viruses responsible will be discussed individually. | 2004 | 15353966 |
| molecular epidemiology of astrovirus infection in italian children with gastroenteritis. | abstract a 1-year study involving 157 gastroenteritis samples was conducted to investigate the role of human astrovirus (hastv) as a cause of gastroenteritis in italian children aged < 2 years. the overall incidence of hastv was 3.1%. most cases occurred between march and may, and four of the five isolates were of the hastv-1 type, the other being hastv-3. analysis of genetic variability showed that the three hastv-1 isolates collected in 2000 clustered together, but separately from the 1999 iso ... | 2004 | 15522011 |
| detection and characterisation of human astroviruses in children with acute gastroenteritis in blantyre, malawi. | in a 2-year hospital-based study of paediatric gastroenteritis in blantyre, malawi, astroviruses were detected by enzyme immunoassay in 15 (1.9%) of 786 inpatients and in 9 (2.3%) of 400 outpatients. greater disease severity was noted in children coinfected with human immunodeficiency virus (hiv). six human astrovirus (hastv) genotypes were identified, including hastv-1 (25%), hastv-2 (21%), hastv-3 (25%), hastv-4 (13%), hastv-5 (4%), and hastv-8 (13%). although astroviruses are not major causes ... | 2002 | 12116005 |
| proteolytic processing of a serotype 8 human astrovirus orf2 polyprotein. | astroviruses require the proteolytic cleavage of the capsid protein to infect the host cell. here we describe the processing pathway of the primary translation product of the structural polyprotein (orf2) encoded by a human astrovirus serotype 8 (strain yuc8). the primary translation product of orf2 is of approximately 90 kda, which is subsequently cleaved to yield a 70-kda protein (vp70) which is assembled into the viral particles. limited trypsin treatment of purified particles containing vp70 ... | 2002 | 12134004 |
| nucleotide correlation between hav isolates from human patients and environmental samples. | hepatitis a disease is endemic in albania even though records from the medical authority show outbreaks involving only limited numbers of people. in the city of lac, 200 people became ill following an outbreak of hepatitis a started on november 2002. the age distribution of the cases shows a peak in the age group 5-9 (43.5%) followed by the age group 10-14 (28%) and the age group 1-4 (18%). no cases were recorded in the age group 0-1. drinking water and sewage samples were collected, using elect ... | 2005 | 15543594 |
| avian astroviruses. | as poultry becomes more important in the world economy, it is increasingly important to fully understand the mechanisms of disease and poor production that affect the industry. to more accurately and reasonably treat these diseases, a more sophisticated understanding of interrelatedness is required. this review focuses on avian astroviruses (aastvs), in particular the recent advances in our understanding of aastv molecular biology, and also history, diagnosis, treatment and control. the known aa ... | 2002 | 12396344 |
| detection of enteric viruses and bacterial indicators in german environmental waters. | a german mining lake and the supplying surface waters, which are located downstream of a sewage plant, were examined regarding their microbiological and virological quality. between october 2002 and september 2003, specific pcr methods were used to determine the occurrence of enteric viruses in 123 water specimens drawn at different sites downstream of the waste water treatment plant and in 9 samples from the sewage plant influent. detection rates in sewage plant effluents and surface water samp ... | 2005 | 15645371 |
| antigenicity of two turkey astrovirus isolates. | astroviruses are positive-sense single-stranded rna viruses. these viruses cause gastroenteritis in humans and in a variety of animal species, including turkey poults. only human astroviruses are well characterized antigenically. in the current study, two turkey astrovirus isolates, tastv1987 and tastv2001, were antigenically compared using cross-neutralization tests in turkey embryos, as well as cross-reactivity of the two isolates by an enzyme-linked immunosorbent assay (elisa). the antigenic ... | 2004 | 15666872 |
| vaccinia virus recombinant expressing an 87-kilodalton polyprotein that is sufficient to form astrovirus-like particles. | human astrovirus is an important cause of acute gastroenteritis. we have generated, for the first time, a vaccinia virus recombinant expressing the astrovirus 87-kda structural polyprotein. the results demonstrate that this expression results in the formation of virus-like particles in the absence of other astrovirus proteins and genomic rna. the purified trypsin-activated virus-like particles strongly resemble the complete astrovirus particles. | 2003 | 12885927 |