| 11. |
- Johansson, Hugo, et al.
(författare)
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Food-borne outbreak of gastroenteritis associated with genogroup I calicivirus.
- 2002
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Ingår i: Journal of Clinical Microbiology. - 1098-660X. ; 40:3, s. 794-798
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Tidskriftsartikel (refereegranskat)abstract
- An outbreak of gastroenteritis affecting 158 of 219 (72%) guests and employees at a hotel is described. Food served at the hotel restaurant is believed to have been the source of the outbreak and to have been contaminated by sick employees working in the restaurant. A secondary attack rate of 22% was seen involving 43 persons in all. In stool specimens from seven of eight patients, Norwalk-like viruses (NLVs) were detected by electron microscopy. While NLV-specific PCR using primers JV12 and JV13 were negative, all specimens examined with primers NVp69 and NVp110 were positive. The failure of primers JV12 and JV13 was attributed to several mismatches in the JV12 primer. Genotyping and sequence analysis revealed that all samples had identical sequences and clustered with genogroup I, and the most closely related well-characterized genotype is Desert Shield. This is the first described food-borne outbreak associated with genogroup I virus in Sweden.
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| 12. |
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| 13. |
- Le Guyader, Francoise S, et al.
(författare)
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Detection of noroviruses in raspberries associated with a gastroenteritis outbreak
- 2004
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Ingår i: International Journal of Food Microbiology. - : Elsevier BV. - 0168-1605 .- 1879-3460. ; 97:2, s. 179-186
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Tidskriftsartikel (refereegranskat)abstract
- Following an acute foodborne gastroenteritis outbreak in southern Sweden, stool specimens from five of nine ill patients were found positive for norovirus using reverse transcriptase polymerase chain reaction. Epidemiological data pointed to raspberry cakes as the source of the outbreak. Using a combination of generic and patient-specific primers and novel food analysis methodology (with extraction efficiency control and inhibitor removal), norovirus strains from two different genogroups were directly identified in the contaminated raspberries.
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| 14. |
- Lopman, Ben, et al.
(författare)
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Increase in viral gastroenteritis outbreaks in Europe and epidemic spread of new norovirus variant
- 2004
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Ingår i: The Lancet. - 0140-6736 .- 1474-547X. ; 363:9410, s. 682-688
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Tidskriftsartikel (refereegranskat)abstract
- Background Highly publicised outbreaks of norovirus gastroenteritis in hospitals in the UK and Ireland and cruise ships in the USA sparked speculation about whether this reported activity was unusual. Methods We analysed data collected through a collaborative research and surveillance network of viral gastroenteritis in ten European countries (England and Wales were analysed as one region). We compiled data on total number of outbreaks by month, and compared genetic sequences from the isolated viruses. Data were compared with historic data from a systematic retrospective review of surveillance systems and with a central database of viral sequences. Findings Three regions (England and Wales, Germany, and the Netherlands) had sustained epidemiological and viral characterisation data from 1995 to 2002. In all three, we noted a striking increase in norovirus outbreaks in 2002 that coincided with the detection and emergence of a new predominant norovirus variant of genogroup II4, which had a consistent mutation in the polymerase gene. Eight of nine regions had an annual peak in 2002 and the new genogroup II4 variant was detected in nine countries. Also, the detection of the new variant preceded an atypical spring and summer peak of outbreaks in three countries. Interpretation Our data from ten European countries show a striking increase and unusual seasonal pattern of norovirus gastroenteritis in 2002 that occurred concurrently with the emergence of a novel genetic variant. In addition to showing the added value of an international network for viral gastroenteritis outbreaks, these observations raise questions about the biological properties of the variant and the mechanisms for its rapid dissemination.
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| 15. |
- Mittelholzer, Christian, et al.
(författare)
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Molecular characterization of a novel astrovirus associated with disease in mink
- 2003
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Ingår i: Journal of General Virology. - : Microbiology Society. - 0022-1317 .- 1465-2099. ; 84:11, s. 3087-3094
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Tidskriftsartikel (refereegranskat)abstract
- Pre-weaning diarrhoea is a well-known problem in mink farming in Europe, causing morbidity that varies between farms, regions and season. Different causalities for the disease have been proposed, but only most recently has a novel astrovirus been identified as an important risk factor. In this report, the molecular characterization, origin and evolution of this novel astrovirus of mink are discussed. The polyadenylated, positive-stranded RNA genome was sequenced and found to contain 6610 nt, organized into three ORFs and two short UTRs. A ribosomal frameshift sequence links the 5' two ORFs, containing sequence motifs for a serine protease (ORF1a) and an RNA-dependent RNA polymerase (ORF1b). The structural proteins are encoded by ORF2 and, presumably, are expressed as a polyprotein precursor to be cleaved into the mature capsid proteins. These results indicate that mink astrovirus (MiAstV) has all of the features typical of members of the Astroviridae. Phylogenetic analyses revealed that MiAstV is distantly related to established astroviruses, showing less than 67 % similarity at the nucleotide level with its closest relative, ovine astrovirus, and even lower identities at the predicted amino acid level. Nevertheless, sequence analysis of MiAstV isolates from geographically distinct Swedish and Danish farms showed much less diversity. This suggests either the spread in the mink population of a virus that has evolved a long time ago or the recent introduction of an ancient virus into a new host species.
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| 16. |
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| 17. |
- Nilsson, David, et al.
(författare)
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All-organic electrochemical device with bi-stable and dynamic functionality
- 2003
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- We will present organic electrochemical transistors that show both bi-stable and dynamic current modulation. In electrochemical devices, both ions and electrons are used as charge carriers. The device is all-organic and has been realized using common printing techniques, such as screen-printing. As the substrate, both cellulose-based paper and polyester foil have been used. PEDOT:PSS (poly(3,4-ethylenedioxythiophene):Poly(styrene sulphonic acid)) is used as the conducting and electrochemical active material. PEDOT:PSS is switched between different redox states, corresponding to semi-conducting and conducting states. Operating voltages is below 2V and on/off ratios up to 105 have been reached (typical value is 5000). The operation of these devices does not depend on any critical dimensions, typical dimensions used are around 200 microns. With a certain geometrical design the dynamic transistor can be employed for frequency doubling. For the bi-stable transistor the modulation of the current is done by direct electronic contact, compared to the dynamic transistor that is modulated by induction of electrochemistry. The electrolyte in these devices can either be solidified or a liquid. The bi-stable device in combination with a layer of Nafion® as electrolyte demonstrates humidity sensor functionality. Since substrates based on paper and common printing techniques can be used for fabrication, this give rise to an environmental friendly and non-expensive device setup.
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| 18. |
- Nilsson, David, et al.
(författare)
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An all-organic sensor-transistor based on a novel electrochemical transducer concept printed electrochemical sensors on paper
- 2002
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Ingår i: Sensors and Actuators B: Chemical. - 0925-4005. ; 86:2-3, s. 193-197
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Tidskriftsartikel (refereegranskat)abstract
- A novel transducer concept based on an organic electrochemical transistor is described. Its function as an integral part of an air humidity sensor, in which the proton conductor Nafion acts as sensitivity layer has been realised. The resulting electrochemical sensor–transistor, based on the conducting polymer PEDOT:PSS, operates at low voltages, on the order of 1 V. The sensor response, measured as the drain–source current of the electrochemical transistor, versus air humidity, has a close to exponential behaviour. The sensor can be realised using exclusively printing and coating fabrication techniques. Here, we demonstrate devices realised on plastic foils and on ordinary coated fine paper substrates. This organic electrochemical transducer promise future applications such as all-integrated low-cost sensor tags for single-use chemical sensors.
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| 19. |
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| 20. |
- Nilsson, Mikael, et al.
(författare)
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Incidence and genetic diversity of group C rotavirus among adults
- 2000
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Ingår i: Journal of Infectious Diseases. - : Oxford University Press (OUP). - 0022-1899 .- 1537-6613. ; 182:3, s. 678-684
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Tidskriftsartikel (refereegranskat)abstract
- Fecal samples from a 1-year prospective study were investigated to establish the role of group C rotavirus infections in acute diarrhea in Swedish adults (>15 years old). Rotaviruses were found in samples from 3% of the patients, and, in 35% of these, group C rotavirus was detected. Clinical symptoms of group C rotavirus infection were generally milder than those of group A rotavirus infection. Gene 8 (vp7) from 12 group C isolates, including strains from the prospective study, a military outbreak, and a sporadic case, was sequenced. The gene was found to be extremely conserved, with identities of 99.1%-100% at the amino acid level. This study has systematically investigated the prevalence and genetic diversity of group C rotavirus in adults. The data confirm the extreme sequence conservation within human group C rotavirus strains and suggest that symptomatic group C rotavirus infections occur more frequently in adults than has been previously recognized.
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