title: Oseltamivir-resistant pandemic (H1N1) 2009 virus infection in England and Scotland, 2009-2010.
abstract: Oseltamivir has been widely used for pandemic (H1N1) 2009 virus infection, and by April 30, 2010, a total of 285 resistant cases were reported worldwide, including 45 in the United Kingdom. To determine risk factors for emergence of oseltamivir resistance and severe infection, a case-control study was conducted in the United Kingdom. Study participants were hospitalized in England or Scotland during January 4, 2009-April 30, 2010. Controls had confirmed oseltamivir-sensitive pandemic (H1N1) 2009 virus infections, and case-patients had confirmed oseltamivir-resistant infections. Of 28 case-patients with available information, 21 (75%) were immunocompromised; 31 of 33 case-patients (94%) received antiviral drugs before a sample was obtained. After adjusting for confounders, case-patients remained significantly more likely than controls to be immunocompromised and at higher risk for showing development of respiratory complications. Selective drug pressure likely explains the development of oseltamivir resistance, especially among immunocompromised patients. Monitoring of antiviral resistance is strongly recommended in this group.
authors: Health Protection Agency, London, UK. calatayudlaurence@yahoo.com
authors: Laurence
authors: L
authors: Calatayud
authors: Angie
authors: A
authors: Lackenby
authors: Arlene
authors: A
authors: Reynolds
authors: Jim
authors: J
authors: McMenamin
authors: Nick F
authors: NF
authors: Phin
authors: Maria
authors: M
authors: Zambon
authors: Richard
authors: R
authors: Pebody
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D024882:Drug Resistance, Viral / Q000235:genetics; D004739:England / Q000453:epidemiology; D005260:Female; D006801:Humans; D007223:Infant; D053118:Influenza A Virus, H1N1 Subtype / Q000187:drug effects* / Q000235:genetics; D007251:Influenza, Human / Q000188:drug therapy / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D009154:Mutation; D009439:Neuraminidase / Q000235:genetics; D053139:Oseltamivir / Q000494:pharmacology* / Q000627:therapeutic use; D058873:Pandemics; D012307:Risk Factors; D012606:Scotland / Q000453:epidemiology; D055815:Young Adult
chemical_list: D053139:Oseltamivir; D009439:Neuraminidase