RESUMEN
A universal stool extraction method for recovery of nucleic acids (NAs) from gastrointestinal pathogens was developed to support rapid diagnostics for the London 2012 Olympics. The method involved mechanical disruption (bead beating) of the stools, followed by automated extraction and detection using real-time PCR. This method had been used extensively in the Second Infectious Intestinal Disease Study (IID2) for the isolation of NA from bacteria and parasites (and was effective for the robust recovery of Cryptosporidium spp.) but had not been used for enteric viruses. To ensure this method was universally suitable, panels of samples known to contain target bacteria, viruses or parasites were processed in triplicate using the pre-treatment method routinely used for each target and the new extraction method (bead beating). The extracts were tested using real-time PCR and the cycle threshold values were compared. The results from this study showed that bead beating improved yields for the bacterial and parasitic targets and was suitable for the viral targets. The implementation of this universal method should confer cost- and time-saving benefits and streamline the processes required for the characterization of an array of pathogens from faecal samples.
Asunto(s)
ADN/aislamiento & purificación , Heces/microbiología , Heces/parasitología , Gastroenteritis/etiología , Técnicas de Diagnóstico Molecular/métodos , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos , Manejo de Especímenes/métodos , Infecciones Bacterianas/diagnóstico , ADN/genética , Humanos , Parasitosis Intestinales/diagnóstico , Londres , Técnicas de Diagnóstico Molecular/economía , Reacción en Cadena en Tiempo Real de la Polimerasa/economía , Manejo de Especímenes/economía , Factores de TiempoRESUMEN
OBJECTIVES: To estimate, overall and by organism, the incidence of infectious intestinal disease (IID) in the community, presenting to general practice (GP) and reported to national surveillance. DESIGN: Prospective, community cohort study and prospective study of GP presentation conducted between April 2008 and August 2009. SETTING: Eighty-eight GPs across the UK recruited from the Medical Research Council General Practice Research Framework and the Primary Care Research Networks. PARTICIPANTS: 6836 participants registered with the 88 participating practices in the community study; 991 patients with UK-acquired IID presenting to one of 37 practices taking part in the GP presentation study. MAIN OUTCOME MEASURES: IID rates in the community, presenting to GP and reported to national surveillance, overall and by organism; annual IID cases and GP consultations by organism. RESULTS: The overall rate of IID in the community was 274 cases per 1000 person-years (95% CI 254 to 296); the rate of GP consultations was 17.7 per 1000 person-years (95% CI 14.4 to 21.8). There were 147 community cases and 10 GP consultations for every case reported to national surveillance. Norovirus was the most common organism, with incidence rates of 47 community cases per 1000 person-years and 2.1 GP consultations per 1000 person-years. Campylobacter was the most common bacterial pathogen, with a rate of 9.3 cases per 1000 person-years in the community, and 1.3 GP consultations per 1000 person-years. We estimate that there are up to 17 million sporadic, community cases of IID and 1 million GP consultations annually in the UK. Of these, norovirus accounts for 3 million cases and 130,000 GP consultations, and Campylobacter is responsible for 500,000 cases and 80,000 GP consultations. CONCLUSIONS: IID poses a substantial community and healthcare burden in the UK. Control efforts must focus particularly on reducing the burden due to Campylobacter and enteric viruses.
Asunto(s)
Enfermedades Transmisibles/epidemiología , Enfermedades Intestinales/epidemiología , Adolescente , Adulto , Anciano , Infecciones por Caliciviridae/diagnóstico , Infecciones por Caliciviridae/epidemiología , Infecciones por Campylobacter/diagnóstico , Infecciones por Campylobacter/epidemiología , Niño , Preescolar , Enfermedades Transmisibles/diagnóstico , Femenino , Medicina General , Humanos , Incidencia , Lactante , Recién Nacido , Enfermedades Intestinales/microbiología , Parasitosis Intestinales/diagnóstico , Parasitosis Intestinales/epidemiología , Modelos Logísticos , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Norovirus/aislamiento & purificación , Vigilancia de la Población , Estudios Prospectivos , Reino Unido/epidemiología , Adulto JovenAsunto(s)
Infecciones por Caliciviridae/complicaciones , Infecciones por Caliciviridae/diagnóstico , Gastroenteritis/complicaciones , Gastroenteritis/diagnóstico , Infecciones por VIH/complicaciones , Norovirus/aislamiento & purificación , Adulto , Fármacos Anti-VIH/uso terapéutico , Infecciones por Caliciviridae/virología , Enfermedad Crónica , Diarrea/virología , Heces/virología , Gastroenteritis/terapia , Gastroenteritis/virología , Infecciones por VIH/tratamiento farmacológico , Humanos , Huésped Inmunocomprometido , Inmunoglobulinas/uso terapéutico , Inmunoterapia/métodos , Masculino , Cumplimiento de la MedicaciónRESUMEN
In this study, we demonstrate that differences within the P2 domain of norovirus genogroup I (GI) strains can be used to segregate outbreaks which are unrelated, whereas complete conservation within this region allows tracking of strains that are part of a single outbreak and likely to have a common source.
Asunto(s)
Infecciones por Caliciviridae , Brotes de Enfermedades , Gastroenteritis , Norovirus/genética , Infecciones por Caliciviridae/epidemiología , Infecciones por Caliciviridae/virología , Proteínas de la Cápside/genética , Análisis por Conglomerados , Heces/virología , Gastroenteritis/epidemiología , Gastroenteritis/virología , Genotipo , Humanos , Datos de Secuencia Molecular , Norovirus/clasificación , Filogenia , Reacción en Cadena de la Polimerasa , ARN Viral/química , Análisis de Secuencia de ADNRESUMEN
Norovirus strains were detected in two patients and in environmental swabs from a pediatric primary immunodeficiency unit in London, United Kingdom, during an infection control incident in November and December 2007. Detailed analyses of the gene encoding the P2 domain demonstrated that the majority of the strains were not related to the patients and that the environmental contamination was most likely due to secondary transfer by the hands of staff or visitors.
Asunto(s)
Infecciones por Caliciviridae , Microbiología Ambiental , Norovirus/aislamiento & purificación , Infecciones por Caliciviridae/microbiología , Infecciones por Caliciviridae/transmisión , Análisis por Conglomerados , Heces/virología , Humanos , Huésped Inmunocomprometido , Lactante , Unidades de Cuidado Intensivo Pediátrico , Masculino , Norovirus/genéticaRESUMEN
BACKGROUND: The human noroviruses are a highly diverse group of viruses with a single-stranded RNA genome encoding a single major structural protein (VP1), which has a hypervariable domain (P2 domain) as the most exposed part of the virion. The noroviruses are classified on the basis of nucleotide sequence diversity in the VP1-encoding ORF2 gene, which divides the majority of human noroviruses into two genogroups (GI and GII). GII-4 noroviruses are the major aetiological agent of outbreaks of gastroenteritis around the world. During a winter season the diversity among the GII-4 noroviruses has been shown to fluctuate, driving the appearance of new virus variants in the population. We have previously shown that sequence data and in silico modelling experiments suggest there are two surface-exposed sites (site A and site B) in the hypervariable P2 domain. We predict these sites may form a functional variant-specific epitope that evolves under selective pressure from the host immune response and gives rise to antibody escape mutants. RESULTS: In this paper, we describe the construction of recombinant baculoviruses to express VLPs representing one pre-epidemic and one epidemic variant of GII-4 noroviruses, and the production of monoclonal antibodies against them. We use these novel reagents to provide evidence that site A and site B form a conformational, variant-specific, surface-exposed site on the GII-4 norovirus capsid that is involved in antibody binding. CONCLUSION: As predicted by our earlier study, significant amino acid changes at site A and site B give rise to GII-4 norovirus epidemic variants that are antibody escape mutants.
Asunto(s)
Anticuerpos Antivirales/inmunología , Epítopos/inmunología , Norovirus/inmunología , Proteínas Estructurales Virales/inmunología , Sustitución de Aminoácidos/genética , Epítopos/genética , Humanos , Modelos Moleculares , Norovirus/genética , Unión Proteica , Estructura Terciaria de Proteína , Proteínas Estructurales Virales/genéticaRESUMEN
UNLABELLED: Norovirus, the most commonly identified cause of both sporadic cases and outbreaks of infectious diarrhoea in developed countries, exhibits a complex epidemiology and has a strong wintertime seasonality. Viral populations are dynamic and evolve under positive selection pressure. METHODS: Time series-adapted Poisson regression models were fitted to daily counts of laboratory reports of norovirus in England and Wales from 1993 to 2006. FINDINGS: Inverse linear associations with daily temperature over the previous seven weeks (rate ratio (RR) = 0.85; 95% CI: 0.83 to 0.86 for every 1 degrees C increase) and relative humidity over the previous five weeks (RR = 0.980; 95% CI: 0.973 to 0.987 for every 1% increase) were found, with temperature having a greater overall effect. The emergence of new norovirus variants (RR = 1.16; 95% CI: 1.10 to 1.22) and low population immunity were also associated with heightened norovirus activity. Temperature and humidity, which may be localised, had highly consistent effects in each region of England and Wales. CONCLUSIONS: These results point to a complex interplay between host, viral and climatic factors driving norovirus epidemic patterns. Increases in norovirus are associated with cold, dry temperature, low population immunity and the emergence of novel genogroup 2 type 4 antigenic variants.
Asunto(s)
Infecciones por Caliciviridae/epidemiología , Gastroenteritis/epidemiología , Interacciones Huésped-Patógeno , Norovirus/patogenicidad , Vigilancia de la Población , Tiempo (Meteorología) , Infecciones por Caliciviridae/virología , Factores de Confusión Epidemiológicos , Inglaterra/epidemiología , Gastroenteritis/virología , Humanos , Distribución de Poisson , Gales/epidemiologíaRESUMEN
The aim of this study was to apply sequence analysis of a hyper variable region of the norovirus (NoV) genome in order to identify point source outbreaks associated with suspect food or water. The hyper-variable region of the gene encoding the P2 domain was chosen as small differences in sequence are likely to indicate virus from different sources whereas identical sequence may reveal transmission routes and the source of contamination. Strains with 100% similarity were considered as originating from a common source, whereas, strains with one or more mutations in the hyper variable region sequenced were regarded as representing unrelated transmission events. This study was able to identify a point source outbreak of a dominant strain, GII-4, on a cruise ship but also of a less common strain, GII-2, between two schools. Also identical GII-3 strains were demonstrated in food handlers amongst the same outbreak; however epidemiologically related outbreaks showed different GII-3 strains indicating multiple sources of contamination.
Asunto(s)
Infecciones por Caliciviridae/epidemiología , Infecciones por Caliciviridae/virología , Brotes de Enfermedades , Gastroenteritis/epidemiología , Gastroenteritis/virología , Norovirus/clasificación , Análisis por Conglomerados , Microbiología Ambiental , Enfermedades Transmitidas por los Alimentos/epidemiología , Enfermedades Transmitidas por los Alimentos/virología , Genotipo , Humanos , Epidemiología Molecular , Datos de Secuencia Molecular , Norovirus/genética , Norovirus/aislamiento & purificación , Análisis de Secuencia , Homología de SecuenciaRESUMEN
The performance of fifteen, commercially available, VZV IgG assays and an "in house" indirect immunofluorescence (IF) assay has been compared to a reference VZV IgG time resolved immunofluorescence assay (VZV TRFIA). A panel of 273 VZV TRFIA IgG positive serum samples and 136 VZV TRFIA IgG susceptible sera, collected from a number of UK hospitals was used. Irrespective of the interpretation of equivocal results the most sensitive assays were Dade Behring EIA (97.4%), "in house" IF (95.2%), Human EIA (92.3%) and Becton Dickinson latex agglutination (94.1%). The least sensitive assays were Virion EIA (69.6%), Diesse EIA (68.9%) and Diasys EIA (68.5%). The least sensitive (<70%) assays all had >99.0% specificity whereas the most sensitive assays had lower specificities; for example, Dade Behring EIA had a specificity of 69.9% when equivocals were treated as VZV IgG negative. For some assays e.g. Dade Behring EIA there were major discrepancies between our findings and those reported by the manufacturer which may reflect the constitution of the panel(s) of sera used for evaluation or the reference method adopted or the choice of cut-off criteria (particularly relevant to our findings for the Behring EIA). Care must be taken to choose an assay with high specificity in order to accurately assess the need for vaccination or immunoprophylaxis; however, high sensitivity is preferable to prevent inappropriate and expensive treatment.
Asunto(s)
Varicela/diagnóstico , Fluoroinmunoensayo/métodos , Herpes Zóster/diagnóstico , Herpesvirus Humano 3/inmunología , Inmunoglobulina G/sangre , Juego de Reactivos para Diagnóstico , Adulto , Anticuerpos Antivirales/sangre , Varicela/virología , Niño , Preescolar , Herpes Zóster/virología , Humanos , Huésped Inmunocomprometido , Tamizaje Masivo/métodos , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Factores de TiempoRESUMEN
The aims of this study were to examine the extent of gastroenteric virus contamination in a pediatric primary immunodeficiency (PPI) ward and a general pediatric ward over a winter season and to determine whether changes to hospital infection control interventions would have an impact on environmental contamination levels within pediatric units. Environmental swabs were collected weekly from 11 sites in both wards from 15 December 2005 to 3 March 2006 and examined for the presence of norovirus (NoV), astrovirus, and rotavirus (RV) by reverse transcriptase PCR. Viruses were detected in 17% and 19% of swabs from both wards. Virus contamination for NoV and RV decreased from 20% to 6% and 15% to 10% of swabs, respectively, in the PPI ward from the 2004 study by Gallimore et al. (C. I. Gallimore, C. Taylor, A. R. Gennery, A. J. Cant, A. Galloway, M. Iturriza-Gomara, and J. J. Gray, J. Clin. Microbiol. 44:395-399, 2006). Overall, changes to cleaning protocols were deemed to have reduced the level of environmental contamination with gastroenteric viruses, but contamination still occurred due to a breakdown in infection control procedures indicated by contamination in areas frequented by parents but used only occasionally by staff.
Asunto(s)
Infecciones por Astroviridae/prevención & control , Infección Hospitalaria/prevención & control , Gastroenteritis/prevención & control , Departamentos de Hospitales/normas , Mamastrovirus , Norovirus , Pediatría/normas , Infecciones por Rotavirus/prevención & control , Rotavirus , Preescolar , Descontaminación , Humanos , Datos de Secuencia Molecular , Estaciones del AñoRESUMEN
BACKGROUND: The use of molecular methods for rotavirus characterisation provides increased sensitivity for typing, and allows the identification of putative reassortant strains. However, due to the constant accumulation of point mutations through genetic drift; and to the emergence of novel genotypes; and possibly zoonotic transmission and subsequent reassortment, the reagents and methods used for genotyping require close monitoring and updating. OBJECTIVES: To design and evaluate a new VP4 consensus oligonucleotide primer pair that provides increased sensitivity and allows typing of strains that were untypeable using available methods. STUDY DESIGN: A total of 489 rotavirus-positive faecal specimens from studies conducted between 1996 and 2006 were used for the evaluation of the new VP4 primers which was performed in the WHO Rotavirus Collaborating and Reference centres in the US, Australia, South Africa and the UK. RESULTS: The new primer pair allowed P-typing of rotavirus strains and provided increased sensitivity, allowing typing of a significant number of strains that previously could not be P-typed. CONCLUSIONS: This study highlights the importance of a constant reconsideration of primer sequences employed for the molecular typing of rotaviruses.
Asunto(s)
Cartilla de ADN/genética , Rotavirus/clasificación , Rotavirus/genética , Australia , Proteínas de la Cápside/genética , Heces/virología , Humanos , ARN Viral/genética , Rotavirus/aislamiento & purificación , Infecciones por Rotavirus/virología , Sensibilidad y Especificidad , Sudáfrica , Reino Unido , Estados UnidosRESUMEN
BACKGROUND: Human noroviruses are a highly diverse group of viruses classified into three of the five currently recognised Norovirus genogroups, and contain numerous genotypes or genetic clusters. Noroviruses are the major aetiological agent of endemic gastroenteritis in all age groups, as well as the cause of periodic epidemic gastroenteritis. The noroviruses most commonly associated with outbreaks of gastroenteritis are genogroup II genotype 4 (GII-4) strains. The relationship between genotypes of noroviruses with their phenotypes and antigenic profile remains poorly understood through an inability to culture these viruses and the lack of a suitable animal model. METHODOLOGY/PRINCIPAL FINDINGS: Here we describe a study of the diversity of amino acid sequences of the highly variable P2 region in the major capsid protein, VP1, of the GII-4 human noroviruses strains using sequence analysis and homology modelling techniques. CONCLUSIONS/SIGNIFICANCE: Our data identifies two sites in this region, which show significant amino acid substitutions associated with the appearance of variant strains responsible for epidemics with major public health impact. Homology modelling studies revealed the exposed nature of these sites on the capsid surface, providing supportive structural data that these two sites are likely to be associated with putative variant-specific epitopes. Furthermore, the patterns in the evolution of these viruses at these sites suggests that noroviruses follow a neutral network pattern of evolution.
Asunto(s)
Sustitución de Aminoácidos , Proteínas de la Cápside/química , Epítopos/química , Norovirus/química , Secuencia de Aminoácidos , Secuencia de Bases , Cartilla de ADN , Datos de Secuencia Molecular , Reacción en Cadena de la Polimerasa , Homología de Secuencia de AminoácidoRESUMEN
Tracking the spread of noroviruses during outbreaks of gastroenteritis is hampered by the lack of sequence diversity in those regions of the genome chosen for virus detection and characterization. Sequence analysis of regions of the genes encoding the RNA-dependent RNA polymerase and the S domain of the capsid does not provide sufficient discrimination between genotypically related strains of different outbreaks. However, analysis of sequences derived from the region encoding the P2 domain showed 100% similarity among strains from the same outbreak and <100% similarity among strains of different outbreaks. The prolonged nature of some hospital outbreaks, links between hospitals, and the introduction of multiple strains of a single genotype associated with an outbreak aboard a cruise ship were determined using this method. This provides a powerful tool for tracking outbreak strains and the subsequent analysis and validation of interventions in a background of multiple introductions of virus strains of the same genotype or genetic cluster.
Asunto(s)
Infecciones por Caliciviridae , Proteínas de la Cápside/genética , Brotes de Enfermedades , Gastroenteritis , Virus Norwalk/clasificación , Virus Norwalk/genética , Análisis de Secuencia de ADN , Secuencia de Bases , Infecciones por Caliciviridae/epidemiología , Infecciones por Caliciviridae/transmisión , Infecciones por Caliciviridae/virología , Heces/virología , Gastroenteritis/epidemiología , Gastroenteritis/virología , Genotipo , Hospitales , Humanos , Virus Norwalk/química , Virus Norwalk/aislamiento & purificación , Filogenia , Reacción en Cadena de la Polimerasa , ARN Viral/análisis , ARN Viral/aislamiento & purificación , Navíos , Especificidad de la Especie , Reino Unido/epidemiologíaRESUMEN
A total of 2,254 fecal samples were tested in a European multicenter evaluation of commercially available norovirus antigen detection assays. Two commercial enzyme immunoassays, IDEIA Norovirus (Oxoid; Thermo Fisher Scientific, Ely, United Kingdom) and RIDASCREEN Norovirus (R-Biopharm, Darmstadt, Germany), were included in the evaluation, and their performance was compared with the results of reverse transcription-PCR (RT-PCR). Included in the evaluation were samples collected in sporadic cases of gastroenteritis, samples from outbreaks in which two or more samples were collected, well-characterized samples representing genotypes currently cocirculating within Europe, and samples collected from patients with gastroenteritis caused by a pathogen other than norovirus. The sensitivities and specificities of the IDEIA Norovirus and RIDASCREEN Norovirus assays were 58.93 and 43.81% and 93.91 and 96.37%, respectively, compared with RT-PCR. The sensitivities of both assays for outbreak investigations improved when six or more samples from an outbreak were examined. The IDEIA Norovirus assay exhibited reactivity to a broader range of norovirus genotypes than the RIDASCREEN Norovirus assay, which showed genotype-dependent sensitivities. The results indicate that, if used, these assays should serve as screening assays and the results should be confirmed by RT-PCR.
Asunto(s)
Antígenos Virales/análisis , Heces/virología , Técnicas para Inmunoenzimas , Norovirus/inmunología , Antígenos Virales/inmunología , Infecciones por Caliciviridae/diagnóstico , Infecciones por Caliciviridae/inmunología , Europa (Continente) , Gastroenteritis/diagnóstico , Gastroenteritis/inmunología , Humanos , Técnicas para Inmunoenzimas/normas , Juego de Reactivos para Diagnóstico , Sensibilidad y EspecificidadRESUMEN
The incidence of calicivirus infection in Ghana and many other African countries is not known. Thirteen (15.9%) of the 82 diarrhoeic stool samples tested for caliciviruses were positive for noroviruses (NoVs). NoVs were present in all age groups and were detected only during the diarrhoea peak that coincided with the peak rotavirus season. Ten (76.9%) of the NoV detected were genogroup II (GII) NoVs and the remaining three (23.1%) genogroup I (GI) NoVs. The predominant GII detected was GII-4 (60%, 6/10). Three of the GII NoVs were determined to be recombinants of GII-8/GII-14 as deduced from the sequencing of the region spanning the Orf1/2 junction. The GII genotypes formed four clusters with published GII sequences. The data shown enhances understanding of NoV diversity in Ghanaian children and demonstrate the global spread of distinct common genotypes to African countries.
Asunto(s)
Infecciones por Caliciviridae/virología , Diarrea/virología , Gastroenteritis/virología , Norovirus/genética , Norovirus/aislamiento & purificación , Enfermedad Aguda , Infecciones por Caliciviridae/epidemiología , Diarrea/epidemiología , Femenino , Gastroenteritis/epidemiología , Ghana/epidemiología , Humanos , Lactante , Masculino , Datos de Secuencia MolecularRESUMEN
BACKGROUND: Noroviruses are highly infectious pathogens that cause gastroenteritis in the community and in semi-closed institutions such as hospitals. During outbreaks, multiple units within a hospital are often affected, and a major question for control programs is: are the affected units part of the same outbreak or are they unrelated transmission events? In practice, investigators often assume a transmission link based on epidemiological observations, rather than a systematic approach to tracing transmission.Here, we present a combined molecular and statistical method for assessing:1) whether observed clusters provide evidence of local transmission and2) the probability that anecdotally|linked outbreaks truly shared a transmission event. METHODS: 76 healthcare associated outbreaks were observed in an active and prospective surveillance scheme of 15 hospitals in the county of Avon, England from April 2002 to March 2003. Viral RNA from 64 out of 76 specimens from distinct outbreaks was amplified by reverse transcription-PCR and was sequenced in the polymerase (ORF 1) and capsid (ORF 2) regions. The genetic diversity, at the nucleotide level, was analysed in relation to the epidemiological patterns. RESULTS: Two out of four genetic and epidemiological clusters of outbreaks were unlikely to have occurred by chance alone, thus suggesting local transmission. There was anecdotal epidemiological evidence of a transmission link among 5 outbreaks pairs. By combining this epidemiological observation with viral sequence data, the evidence of a link remained convincing in 3 of these pairs. These results are sensitive to prior beliefs of the strength of epidemiological evidence especially when the outbreak strains are common in the background population. CONCLUSION: The evidence suggests that transmission between hospitals units does occur. Using the proposed criteria, certain hypothesized transmission links between outbreaks were supported while others were refuted. The combined molecular/epidemiologic approach presented here could be applied to other viral populations and potentially to other pathogens for a more thorough view of transmission.
Asunto(s)
Infecciones por Caliciviridae/transmisión , Infecciones por Caliciviridae/virología , Infección Hospitalaria/transmisión , Infección Hospitalaria/virología , Brotes de Enfermedades , Transmisión de Enfermedad Infecciosa , Gastroenteritis/epidemiología , Norovirus/genética , Infecciones por Caliciviridae/epidemiología , Infección Hospitalaria/epidemiología , Inglaterra/epidemiología , Gastroenteritis/virología , Humanos , Epidemiología Molecular/métodos , Reacción en Cadena de la Polimerasa/métodos , Estudios Prospectivos , Reacción en Cadena de la Polimerasa de Transcriptasa InversaRESUMEN
A fecal archive containing 115 sapovirus (SaV) strains detected in samples collected from 15 outbreaks and 98 sporadic cases of gastroenteritis between 1989 and 2004 in the UK were characterized in order to determine the genomic diversity within SaV co-circulating in the human population. Strains were characterized by partial sequencing of the genes encoding the RNA-dependent RNA polymerase (RdRp) region and/or the polymerase/capsid (Pol/Cap) junction of the open reading frame (Orf) 1. Overall, SaV of genogroup I genotype 1 (GI 1) were the predominant strains circulating in the UK in each year between 1989 and 2004. During 2004, GII 1 was the predominant strain. These two SaV types accounted for 89.5% of the sporadic cases and outbreaks in the UK. The remaining cases were caused by six other SaV genotypes. On the basis of partial sequencing of the RdRp and capsid encoding genes of strains, which did not show sufficient homology to any of the currently recognized genotypes, we propose the inclusion of a presumptive fourth genotype within genogroup I (GI 4).
Asunto(s)
Infecciones por Caliciviridae/epidemiología , Brotes de Enfermedades , Gastroenteritis/epidemiología , Variación Genética , Epidemiología Molecular , Sapovirus/genética , Adulto , Infecciones por Caliciviridae/virología , Cápside/metabolismo , Niño , Preescolar , Heces/virología , Genes Virales/genética , Humanos , Lactante , Irak , Sistemas de Lectura Abierta/genética , ARN Polimerasa Dependiente del ARN/genética , ARN Polimerasa Dependiente del ARN/metabolismo , Sapovirus/clasificación , Especificidad de la Especie , Reino Unido/epidemiologíaRESUMEN
The aim of this study was to determine if gastroenteric viruses were present on surfaces and equipment in a pediatric primary immunodeficiency unit (PPIU) by environmental sampling using swabs and subsequent nucleic acid extraction and reverse transcriptase PCR assays. A PPIU was chosen, and 11 swabs were taken at the same sites every 2 weeks for 6 months. Nested/heminested PCR assays were used to screen for astroviruses (AsV), noroviruses (NoV), and rotaviruses (RV). AsV, NoV, and RV were detected at multiple swab sites during the study period. NoV was the most frequently detected virus on environmental surfaces; however, RV was detected on 79% and NoV on 50% of swabbing dates during the study period. Toilet taps were the most contaminated sites. Fecal samples from selected patients in the unit were also screened during the study period, and patients excreted AsV, NoV, and RV at times during the study. New cleaning schedules and changes in some of the PPIU sanitary furniture have been suggested as a means of reducing environmental contamination.
Asunto(s)
Monitoreo del Ambiente/métodos , Gastroenteritis/virología , Unidades Hospitalarias , Síndromes de Inmunodeficiencia/complicaciones , Mamastrovirus/aislamiento & purificación , Norovirus/aislamiento & purificación , Rotavirus/aislamiento & purificación , Preescolar , Microbiología Ambiental , Heces/virología , Humanos , Lactante , Masculino , Pediatría , Infecciones por Virus ARN/virología , Reacción en Cadena de la Polimerasa de Transcriptasa InversaRESUMEN
Gastroenteritis affected many British military personnel during the war in Iraq. In the first month, 1,340 cases were seen; 73% of patients required hospital admission and 36% were hospital staff. In a survey of 500 hospital staff, 76% reported gastroenteritis, which was more likely in clinical workers. Investigations showed only caliciviruses.
Asunto(s)
Brotes de Enfermedades , Gastroenteritis/epidemiología , Personal Militar , Guerra , Adolescente , Adulto , Infecciones por Caliciviridae/epidemiología , Infecciones por Caliciviridae/virología , Femenino , Gastroenteritis/fisiopatología , Gastroenteritis/virología , Humanos , Irak/epidemiología , Masculino , Persona de Mediana Edad , Norovirus/aislamiento & purificación , Personal de Hospital , Factores de Riesgo , Reino UnidoRESUMEN
An outbreak of astrovirus gastroenteritis occurred in the Primary Immunodeficiency Unit at Newcastle General Hospital in March 2004. Environmental swabbing of the unit was undertaken after the outbreak, with multiple sites swabbed pre- and postcleaning. Astroviruses were detected in four environmental swabs and from two patient fecal samples using heminested reverse transcriptase PCR. An astrovirus genotype 3 strain was identified in both environmental swabs and fecal specimens and was the strain identified as being responsible for the outbreak. Environmental transmission of the virus was thought to have occurred by contamination of a syringe pump outside the laminar-flow curtain of a patient who was admitted with astrovirus gastroenteritis. This was subsequently transmitted to a cubicle next door and to a television/games console in a parents' room in the ward. Environmental monitoring of surfaces/equipment, using PCR assays for gastroenteric viruses in hospital situations where infection can give rise to serious clinical complications, may have a role in controlling and monitoring cleaning and the subsequent prevention of nosocomial transmission of gastroenteritis.