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Basic Characteristics of Mutations
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Mutation Site
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D344N |
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Mutation Site Sentence
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Although the D344N substitution in NA has been associated with increases in the enzyme activity, this amino acid is common to both clades 2B and 2C, and none of the clade-specific differences between the NA (13 amino acids) or HA (6 amino acids) can readily account for the greater proportion of ORVs in clade 2B over clade 2C viruses. |
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Mutation Level
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Amino acid level |
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Mutation Type
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Nonsynonymous substitution |
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Gene/Protein/Region
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NA |
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Standardized Encoding Gene
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NA
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Genotype/Subtype
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H1N1 |
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Viral Reference
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-
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Functional Impact and Mechanisms
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Disease
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Influenza A
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Immune
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- |
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Target Gene
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-
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Clinical and Epidemiological Correlations
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Clinical Information
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- |
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Treatment
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- |
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Location
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Europe |
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Literature Information
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PMID
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19331731
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Title
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Oseltamivir-resistant influenza virus A (H1N1), Europe, 2007-08 season
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Author
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Meijer A,Lackenby A,Hungnes O,Lina B,van-der-Werf S,Schweiger B,Opp M,Paget J,van-de-Kassteele J,Hay A,Zambon M
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Journal
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Emerging infectious diseases
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Journal Info
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2009 Apr;15(4):552-60
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Abstract
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In Europe, the 2007-08 winter season was dominated by influenza virus A (H1N1) circulation through week 7, followed by influenza B virus from week 8 onward. Oseltamivir-resistant influenza viruses A (H1N1) (ORVs) with H275Y mutation in the neuraminidase emerged independently of drug use. By country, the proportion of ORVs ranged from 0% to 68%, with the highest proportion in Norway. The average weighted prevalence of ORVs across Europe increased gradually over time, from near 0 in week 40 of 2007 to 56% in week 19 of 2008 (mean 20%). Neuraminidase genes of ORVs possessing the H275Y substitution formed a homogeneous subgroup closely related to, but distinguishable from, those of oseltamivir-sensitive influenza viruses A (H1N1). Minor variants of ORVs emerged independently, indicating multiclonal ORVs. Overall, the clinical effect of ORVs in Europe, measured by influenza-like illness or acute respiratory infection, was unremarkable and consistent with normal seasonal activity.
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Sequence Data
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-
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