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- Johansen, Kari, et al.
(författare)
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Norovirus strains belonging to the GII.4 genotype dominate as a cause of nosocomial outbreaks of viral gastroenteritis in Sweden 1997-2005 - Arrival of new variants is associated with large nation-wide epidemics
- 2008
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Ingår i: Journal of Clinical Virology. - : Elsevier BV. - 1386-6532 .- 1873-5967. ; 42:2, s. 129-134
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Tidskriftsartikel (refereegranskat)abstract
- Background: In recent years an increase of the incidence of nosocomial outbreaks caused by noroviruses has been observed throughout Sweden, with high peaks noted in the winter seasons 2002/2003 and 2004/2005, respectively. Objectives: To phylogenetically characterize norovirus strains causing nosocomial outbreaks from 1997 to 2005 and estimate the impact of norovirus-like disease on the Swedish health care system during the peak season 2002/2003 when a new variant of norovirus occurred. Study design: Stool samples from 115 randomly selected nosocomial outbreaks occurring during 1997-2005 throughout Sweden were studied by RT-PCR and sequencing. In addition, to investigate the impact on the health-care system, a questionnaire was distributed to infection control units (n = 90) serving all Swedish hospitals, nursing homes and other health-care institutions during the largest epidemic of nosocomial outbreaks. Results: Sequencing of 279 nucleotides of the norovirus RNA polymerase gene in stools containing norovirus RNA showed that strains belonging to the GII.4 genotype dominated. Each of the two large epidemics was due to a new variant within this cluster. The questionnaire revealed that 30,000-35,000 episodes of nosocomial norovirus-like infections occurred in 80 of 82 major Swedish hospitals affected in 2002/2003. Conclusion: New norovirus variants within the cluster GGII.4 may have a major impact on the health-care system. (c) 2008 Elsevier B.V. All rights reserved.
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| 2. |
- Tiveljung Lindell, Annika, et al.
(författare)
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Molecular epidemiology of norovirus infections in Stockholm, Sweden, during the years 2000 to 2003 : Association of the GGIIb genetic cluster with infection in children
- 2005
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Ingår i: Journal of Clinical Microbiology. - 0095-1137 .- 1098-660X. ; 43:3, s. 1086-1092
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Tidskriftsartikel (refereegranskat)abstract
- The incidence of norovirus-associated gastroenteritis and the molecular epidemiology of norovirus strains were studied during three seasons (2000-2001, 2001-2002, and 2002-2003) among patients of all ages, mainly from the Stockholm region in Sweden. A total of 3,252 fecal samples were analyzed by reverse transcription-PCR. The incidences of norovirus infection among adults were 23, 26, and 30% during the three seasons studied and 18,11, and 15% among children 0 to 15 years of age. During the first season, all norovirus strains detected by PCR were typed either by reverse line blot hybridization or nucleotide sequence analysis. During the two successive seasons, a total of 60 norovirus-positive strains from the beginning, peak, and end of the seasons were selected for nucleotide sequence analysis. We identified two dominant noroviras variants over the seasons: a new norovirus variant, recently described as the GGIIb genetic cluster, dominated among children during the first season, and during the following two seasons, a GGII-4 variant dominated. Our data suggest that norovirus infections are common, not only among adults, but also among children, and that some strains may predominantly affect children. Copyright © 2005, American Society for Microbiology. All Rights Reserved.
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